Samsung Digital Laser MFP SCX 4720F Series SCX 4720 SCX 4520 Parts Service Manual

DIGITAL LASER MFP
SCX-4720F Series
SCX-4720F
SCX-4520
SERVICE Manual
DIGITAL LASER MFP CONTENTS
1. Precautions
2. Reference Information
3. Specifications
4. Summary of product
5. Disassembly and Reassembly
6. Alignment and Adjustments
7. Troubleshooting
8. Exploded Views and Parts List
9. Block Diagram
10. Connection Diagram
11. Schematic Diagram
Precautions
1
1. Precautions
In order to prevent accidents and to prevent damage to the equipment please read the precautions listed
below carefully before servicing the printer and follow them closely.
1.1 Safety Warning

(1) Only to be serviced by appropriately qualified service engineers.
High voltages and lasers inside this product are dangerous. This printer should only be serviced by a suitably
trained and qualified service engineer.
(2) Use only Samsung replacement parts

There are no user serviceable parts inside the printer. Do not make any unauthorized changes or
additions to the printer, these could cause the printer to malfunction and create electric shock or fire haz-ards.
(3) Laser Safety Statement

The Printer is certified in the U.S. to conform to the requirements of DHHS 21 CFR, chapter 1 Subchapter J for
Class 1(1) laser products, and elsewhere, it is certified as a Class I laser product
conforming to the requirements of IEC 825. Class I laser products are not considered to be hazardous. The
laser system and printer are designed so there is never any human access to laser radiation above a Class I
level during normal operation, user maintenance, or prescribed service condition.
Warning >> Never operate or service the printer with the protective cover removed from Laser/Scanner assembly. The
reflected beam, although invisible, can damage your eyes. When using this product, these basic safety
pre-cautions should always be followed to reduce risk of fire, electric shock, and injury to persons.
CAUTION - INVISIBLE LASER RADIATION

WHEN THIS COVER OPEN.
DO NOT OPEN THIS COVER.
VORSICHT - UNSICHTBARE LASERSTRAHLUNG,
WENN ABDECKUNG GE FFNET.
NICHT DEM STRAHL AUSSETZEN.
ATTENTION - RAYONNEMENT LASER INVISIBLE EN CAS
D OUVERTURE. EXPOSITION DANGEREUSE
AU FAISCEAU.
ATTENZIONE - RADIAZIONE LASER INVISIBILE IN CASO DI
APERTURA. EVITARE L ESPOSIZIONE AL
FASCIO.
PRECAUCION - RADIACION LASER IVISIBLE CUANDO SE ABRE.
EVITAR EXPONERSE AL RAYO.
ADVARSEL. - USYNLIG LASERSTR LNING VED BNING, N R
SIKKERHEDSBRYDERE ER UDE AF FUNKTION.
UNDG UDSAETTELSE FOR STR LNING.
ADVARSEL. - USYNLIG LASERSTR LNING N R DEKSEL
PNES. STIRR IKKE INN I STR LEN.
UNNG EKSPONERING FOR STR LEN.
VARNING - OSYNLIG LASERSTR LNING N R DENNA DEL
R PPNAD OCH SP RREN R URKOPPLAD.
BETRAKTA EJ STR LEN. STR LEN R FARLIG.
VARO! - AVATTAESSA JA SUOJALUKITUS OHITETTAESSA
OLET ALTTIINA N KYM TT M LLE LASER-
S TEILYLLE L KATSO S TEESEEN.
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Precautions
1.2 Caution for safety
1.2.1 Toxic material
This product contains toxic materials that could cause illness if ingested.
(1) If the LCD control panel is damaged it is possible for the liquid inside to leak. This liquid is toxic. Contact with the skin
should be avoided, wash any splashes from eyes or skin immediately and contact your doctor. If the liquid gets into
the mouth or is swallowed see a doctor immediately.
(2) Please keep toner cartridges away from children. The toner powder contained in the toner cartridge may be harmful
and if swallowed you should contact a doctor.
1.2.2 Electric Shock and Fire Safety Precautions
Failure to follow the following instructions could cause electric shock or potentially cause a fire.
(1) Use only the correct voltage, failure to do so could damage the printer and potentially cause a fire or electric
shock.
(2) Use only the power cable supplied with the printer. Use of an incorrectly specified cable could cause the cable
to overheat and potentially cause a fire.
(3) Do not overload the power socket, this could lead to overheating of the cables inside the wall and could lead to
a fire.
(4) Do not allow water or other liquids to spill into the printer, this can cause electric shock. Do not allow paper
clips, pins or other foreign objects to fall into the printer these could cause a short circuit leading to an electric
shock or fire hazard..
(5) Never touch the plugs on either end of the power cable with wet hands, this can cause electric shock. When
servicing the printer remove the power plug from the wall socket.
(6) Use caution when inserting or removing the power connector. The power connector must be inserted com-
pletely otherwise a poor contact could cause overheating possibly leading to a fire. When removing the power
connector grip it firmly and pull.
(7) Take care of the power cable. Do not allow it to become twisted, bent sharply round corners or otherwise
damaged. Do not place objects on top of the power cable. If the power cable is damaged it could overheat and
cause a fire or exposed cables could cause an electric shock. Replace a damaged power cable immediately,
do not reuse or repair the damaged cable. Some chemicals can attack the coating on the power cable,
weakening the cover or exposing cables causing fire and shock risks.
(8) Ensure that the power sockets and plugs are not cracked or broken in any way. Any such defects should be
repaired immediately. Take care not to cut or damage the power cable or plugs when moving the machine.
(9) Use caution during thunder or lightening storms. Samsung recommend that this machine be disconnected from
the power source when such weather conditions are expected. Do not touch the machine or the power cord if it
is still connected to the wall socket in these weather conditions.
(10) Avoid damp or dusty areas, install the printer in a clean well ventilated location. Do not position the machine
near a humidifier. Damp and dust build up inside the machine can lead to overheating and cause a fire.
(11) Do not position the printer in direct sunlight. This will cause the temperature inside the printer to rise possibly
leading to the printer failing to work properly and in extreme conditions could lead to a fire.
(12) Do not insert any metal objects into the machine through the ventilator fan or other part of the casing, it could
make contact with a high voltage conductor inside the machine and cause an electric shock.
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Precautions
1.2.3 Handling Precautions
The following instructions are for your own personal safety, to avoid injury and so as not to damage the printer
(1) Ensure the printer is installed on a level surface, capable of supporting its weight. Failure to do so could cause
the printer to tip or fall.
(2) The printer contains many rollers, gears and fans. Take great care to ensure that you do not catch your fingers,
hair or clothing in any of these rotating devices.
(3) Do not place any small metal objects, containers of water, chemicals or other liquids close to the printer which if
spilled could get into the machine and cause damage or a shock or fire hazard.
(4) Do not install the machine in areas with high dust or moisture levels, beside on open window or close to a
humidifier or heater. Damage could be caused to the printer in such areas.
(5) Do not place candles, burning cigarettes, etc. on the printer, these could cause a fire.
1.2.4 Assembly / Disassembly Precautions
Replace parts carefully, always use Samsung parts. Take care to note the exact location of parts and also
cable routing before dismantling any part of the machine. Ensure all parts and cables are replaced correctly.
Please carry out the following procedures before dismantling the printer or replacing any parts.
(1) Check the contents of the machine memory and make a note of any user settings. These will be erased if the
mainboard or network card is replaced.
(2) Ensure that power is disconnected before servicing or replacing any electrical parts.
(3) Disconnect printer interface cables and power cables.
(4) Only use approved spare parts. Ensure that part number, product name, any voltage, current or temperature
rating are correct.
(5) When removing or re-fitting any parts do not use excessive force, especially when fitting screws into plastic.
(6) Take care not to drop any small parts into the machine.
(7) Handling of the OPC Drum
- The OPC Drum can be irreparably damaged if it exposed to light.
Take care not to expose the OPC Drum either to direct sunlight or to fluorescent or incandescent room
lighting. Exposure for as little as 5 mins can damage the surface’s photoconductive properties and will result
in print quality degradation. Take extra care when servicing the printer. Remove the OPC Drum and store it in
a black bag or other lightproof container. Take care when working with the covers(especially the top cover)
open as light is admitted to the OPC area and can damage the OPC Drum.
- Take care not to scratch the green surface of OPC Drum Unit.
If the green surface of the Drum Cartridge is scratched or touched the print quality will be compromised.
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Precautions
1.2.5 Disregarding this warning may cause bodily injury
(1) Be careful with the high temperature part.

The fuser unit works at a high temperature. Use caution when working on the printer. Wait for the fuser to cool
down before disassembly.
(2) Do not put finger or hair into the rotating parts.
When operating a printer, do not put hand or hair into the rotating parts (Paper feeding entrance, motor, fan,
etc.). If do, you can get harm.
(3) When you move the printer.
This printer weighs 15.6kg including toner cartridge and cassette. Use safe lifting and handling techniques. Use
the lifting handles located on each side of the machine. Back injury could be caused if you do not lift carefully.
(4) Ensure the printer is installed safely.

The printer weighs 15.6Kg, ensure the printer is installed on a level surface, capable of supporting its weight.
Failure to do so could cause the printer to tip or fall possibly causing personal injury or damaging the printer.
(5) Do not install the printer on a sloping or unstable surface. After installation, double check that the printer is stable.
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Precautions
1.3 ESD Precautions
Certain semiconductor devices can be easily damaged by static electricity. Such components are commonly called
“Electrostatically Sensitive (ES) Devices”, or ESDs. Examples of typical ESDs are: integrated circuits, some field
effect transistors, and semiconductor “chip” components.
The techniques outlined below should be followed to help reduce the incidence of component damage caused by
static electricity.
Caution >>Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
1. Immediately before handling a semiconductor component or semiconductor-equipped assembly, drain off any
electrostatic charge on your body by touching a known earth ground. Alternatively, employ a commercially avail-
able wrist strap device, which should be removed for your personal safety reasons prior to applying power to the
unit under test.
2. After removing an electrical assembly equipped with ESDs, place the assembly on a conductive surface, such as
aluminum or copper foil, or conductive foam, to prevent electrostatic charge buildup in the vicinity of the assem-
bly.
3. Use only a grounded tip soldering iron to solder or desolder ESDs.
4. Use only an “anti-static” solder removal device. Some solder removal devices not classified as “anti-static” can
generate electrical charges sufficient to damage ESDs.
5. Do not use Freon-propelled chemicals. When sprayed, these can generate electrical charges sufficient to dam-
age ESDs.
6. Do not remove a replacement ESD from its protective packaging until immediately before installing it. Most
replacement ESDs are packaged with all leads shorted together by conductive foam, aluminum foil, or a compa-
rable conductive material.
7. Immediately before removing the protective shorting material from the leads of a replacement ESD, touch the pro-
tective material to the chassis or circuit assembly into which the device will be installed.
8. Maintain continuous electrical contact between the ESD and the assembly into which it will be installed, until com-
pletely plugged or soldered into the circuit.
9. Minimize bodily motions when handling unpackaged replacement ESDs. Normal motions, such as the brushing
together of clothing fabric and lifting one’s foot from a carpeted floor, can generate static electricity sufficient to
damage an ESD.
1.4 Super Capacitor or Lithium Battery Precautions
1. Exercise caution when replacing a super capacitor 3. Super capacitor or Lithium batteries contain toxic
or Lithium battery. There could be a danger of substances and should not be opened, crushed, or
explosion and subsequent operator injury and/or burned for disposal.
equipment damage if incorrectly installed.
2. Be sure to replace the battery with the same or 4. Dispose of used batteries according to the
equivalent type recommended by the manufacturer. manufacture’s instructions.
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Reference Information
2
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2. Reference Information
This chapter contains the tools list, list of abbreviations used in this manual, and a guide to the
location space required when installing the printer. A definition of test pages and Wireless
Network information definition is also included.
2.1 Tool for Troubleshooting

The following tools are recommended safe and easy troubleshooting as described in this service manual.
• DVM (Digital Volt Meter) • Cleaning Equipments

Standard : Indicates more than 3 digits. Standard : An IPA (Isopropyl Alcohol) dry wipe tissue or
a gentle neutral detergent and lint-free cloth.
• Driver
Standard : "-" type, "+" type (M3 long, M3 short, M2 • Vacuum Cleaner
long, M2 short).
• Spring Hook
Standard : For general use
• Tweezers
Standard : For general home use, small type.
• Cotton Swab
Standard : For general home use, for medical service.
• Software (Driver) installation CD ROM
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2.2 Acronyms and Abbreviations

The table in the below explains abbreviations used in this service manual.
The contents of this service manual are declared with abbreviations in many parts. Please refer to the
table.
AC Alternating Current IC integrated circuit

ADF Automatic Document Feeder IDE Intelligent Drive electronics or Imbedded
Drive Electronics
ASIC Application Specific Integrated Circuit
IEEE Institute of Electrical and Electronics
ASSY assembly
Engineers. Inc
BIOS Basic Input Output System
IPA Isopropy Alcohol
CCD Charge Coupled Device
IPM Images Per Minute
CMOS Complementary Metal Oxide Semiconductor
LAN local area network
CN connector
lb pound(s)
CON connector
LBP Laser Beam Printer
CPU Central Processing Unit
LCD Liquid Crystal Display
CRUM Customer Replaceable Unit Memory
LED Light Emitting Diode
dB decibel
LSU Laser Scanning Unit
dbA decibelampere
MB Megabyte
dBM decibel milliwatt
MFP Multi-Functional Product
DC direct current
MHz Megahertz
DCU Diagnostic Control Unit
NVRAM Nonvolatile random access memory
DPI Dot Per Inch
OPC Organic Photo Conductor
DRAM Dynamic Random Access Memory
PBA Printed Board Assembly
DVM Digital Voltmeter
PCL Printer Command Language , Printer Control
ECP Enhanced Capability Port Language
EEPROM Electronically Erasable Programmable Read PDL Page Discription Language
Only Memory
PPM Page Per Minute
EMI Electro Magnetic Interference
PTL Pre-Transfer Lamp
EP electrophotographic
Q’ty Quantity
EPP Enhanced Parallel Port
RAM Random Access Memory
FCOT First Copy Out Time
ROM Read Only Memory
F/W firmware
SCF Second Cassette Feeder
GDI graphics device interface
SMPS Switching Mode Power Supply
GND ground
SPGP Samsung Printer Graphic Processor
HBP Host Based Printing
SPL Samsung Printer Language
HDD Hard Disk Drive
Spool Simultaneous Peripheral Operation Online
HV high voltage
SW Switch
HVPS High Voltage Power Supply
Sync Synchronous or synchronization
I/F interface
TBD To Be Determined
I/O Input and Output
USB Universal Serial Bus
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2.3 The Sample Pattern for the Test

The sample pattern shown in below is the standard pattern used in the factory.
The life of the toner cartridge and the printing speed are measured using the pattern shown below.
(The image is 70% of the actual A4 size).
2.3.1 A4 5% Pattern
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2.3.2 A4 2% Pattern
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2.3.3 A4 IDC 5% Patten
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2.3.4 A4 ISO 19752 Standard Pattern

This test page is reproduced at 70% of the normal A4 size
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2.4 Wireless LAN

• This product uses a printing function with a wireless LAN, which is an option.
- The wireless LAN function uses a frequency instead of connecting LAN cable to connect data to
an access point for print.
- For a wireless LAN connection, an AP is needed, It is possible to use wireless LAN onnection with
wired LAN. Also, if AP is installed in an office or at home, the wireless LAN function can be simply
used.
• Types of desk top PC (or Lap top) that uses the wireless LAN.
Division Basic type Recommend type
CPU Over PENTIUM 233M PENTIUM 300MHz

MEMORY Over 64MB Over 128MB
VIDEO CARD Over 800X600 Over 1024X768
OS Over WINDOWS 98 Over WINDOWS ME
INTERFACE CARD A product has a certificated mark of Wi-FiTM
• About the certificated mark of Wi-FiTM
- The Wi-FiTM is a registered trademark of WECA (Wireless Ethernet

Compatibility Alliance). Over 50 of a wireless LAN companies are member
of it. The most of main wireless networking companies are attending and
the main companies are Lucent technologies, Cisco, Intel/Symbol, 3Com,
Enterasys (Cabletron), Compaq, IBM, Nokia, Dell, Philips, Samsung elec-
tronic, Sony, Intersil, and so on. This mark certifies mutual compatibility
among product has Wi-FiTM (IEEE 802.1) and it is certified as a standard of
a wireless LAN market.
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Specifications
3
3. Specifications
Specfications are correct at the time of printing. Product specifications are subject to change without notice.
See below for product specifications.
3.1 General Specifications

Items SCX-4520 SCX-4720F
Major Features Copier, Print, Scan, ADF, Fax, Copier, Print, Scan, ADF,
Scan-to-Email (Through Smar Scan-to-Email (Through
Thru S/W) Direc Print, Smar Thru S/W) Direc Print,
Scan-to-USB Memory Scan-to-USB Memory
Size (W*D*H) w/o Hand Set 450mmx423mmx456mm (17.7x16.7x18")
Net Weight(Inc. Toner Cartridge) 15.6kg
Net Weight(exc. Toner Cartridge) 14.8kg
Gross Weight(with package) 20.4kg
LCD 16*2 Char
I/O Interface USB2.0 (High Speed)
MPU SPGPm / 166MHz
Power Consumption Printing Operation 370W
Sleep Mode 30 W Energy Star Compliant
Power Switch Yes
Power Supply Input Voltage Low Voltage : 110 ~ 127VAC
High Voltage : 220 ~ 240VAC
Input Frequency 50 / 60Hz(+/- 3Hz)
Noise Printing 54dBA
Copy 55dBA
Standby 33dBA
Warm Up Time from Cold Status Less than 42 seconds
Machine Life Max. Monthly Print 15,000pages
Volume Scan 1,000pages
(Duty Cycle) ADF 1,000pages
Average Monthly Print Volume 1,500pages
Machine Life 150,000pages
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Specifications

Periodic Replacing Pickup Roller 150,000 Pages
Parts
Pad Unit(Tray) 150,000 Pages
Pad Unit (ADF) 20,000 Pages
Transfer Roller 60,000 Pages
Fuser Unit 80,000 Pages
Environmental Temperature Operating 10~32°C
Non Operating -20~40°C
Humidity Operating 20~80%
Non Operating 10~90%
Altitude Max 8,200ft
EMI Approval Class B
Device Memory Standard / Max. 32MB/160MB(Std./Max)
12MB(PS) + 4MB(FAX) + 2MB
(System) + 2MB(Scan) = 20MB
Type SDRAM
Expand Memory Slot Type SDRAM DIMM - Option DIMM : 16, 32,
64, 128MB (SDRAM)
- 100Pin SDRAM DIMM
(Use only Samsung
Memory parts made
Specifically for this printer)
Compression Technology YES
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Specifications
3.2 Print Specification

PRINT Print Speed Up to 22ppm/Ltr, 20ppm/A4 (600 dpi)
Print Emulation GDI, PCL6, PCL5e PostScript Level3(opt.)
*Korea (KS / KSSM / KSC5895)
Auto Emulation Sensing YES
Font Type 45 Scalable, 1 Bitmap
Number N/A
Power Save Yes(5/10/15/30/45min.)
Resolution Normal 600x600dpi
RET Yes (1200x1200dpi)
Toner Save Yes (No dedicated button on CP)
Memory 16MB
FPOT From Stand by Approx. 10 seconds (From LSU ‘ON’, A4)
From Cold Status Less than 50 seconds
Duplex Print N.A
Printable Area 208 x 273 mm (Letter)
Halftone(Gray Scale) 128levels
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Specifications
3.3 Scan Specification

SCAN Scan Method Color CCD
Scan Speed Linearity Approx. 75sec (USB 1.1) *USB 1.1,
through ADF Gray Approx. 75sec (USB 1.1) 300dpi,
Letter Size,
Color Approx. 150sec (USB 1.1) Pentimum
Scan Speed Linearity Approx.75sec (USB 1.1) 41.xGHz,
128MB RAM
through Platen Gray Approx. 75sec (USB 1.1)
Color Approx. 150sec (USB 1.1)
75dpi/300dpi
Resolution Optical 600*1200dpi
Enhanced 4800dpi*4800dpi
Halftone 256level
Scan Size Max. Document Max.216mm(8.5")
Width
Effective Max 208mm(8.2inch)
Scan Width
Scan-to E-mail, Image, OCR, FAX, WEB --> through PC
Direct Scan-to-USB Memory(Std.)
Scan Depth Color 24 bit
Mono 1bit for Lineart, 8 Bit for Gray scale
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Specifications
3.4 Copy Specification

COPY Copy Quality Text 600x300dpi

Selection or
Original Image Text/Photo 600x300dpi
type selection Photo 600x600dpi for Platen
Mode
Other N/A
FCOT Stand by Approx. 10 seconds:Platen
Approx. 15 seconds:ADF
From Cold Status 50 seconds
Copy Speed SDMC at all mode 22cpm/Ltr, 20cpm/A4
/ Letter MDMC at Text, 14cpm
(600x300dpi)
MDMC at Photo 8cpm
Mode
(600x600dpi)
Origin Platen REAR LEFT
Alignment ADF Center
Resolution Scan:600x300dpi, 600*600dpi
Print:600*600dpi
Zoom Range 25% to 400% for Platen
25% to 100% for ADF
Multi Copy 1~99
Preset Yes
Darkness Control 3 level(by LED)
Copy Mode(=Quality) Text, Mixed, Photo
Collation Copy 600x300dpi : Yes
Auto return to default mode Yes (Time can be changeable 15, 30, 60, 180sec, Off)
Changeable Default mode Contrast, Image, Reduce/Enlarge, No. of Copies
Special Copy N-up copy 2-up, 4-up
Collation Copy Yes(ADF only)
AutoFit Copy Yes(Platen only)
2-side Copy Yes(Platen only)
* Copy 2-side printed original document into one page
(ex. ID Card Copy)
Clone Yes(Platen only)
Poster Yes(Platen only)
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Specifications
TELEPHONE Handset No No
On hook Dial No Yes
Search No Yes (Phone Book)
1-Touch Dial No 40EA (20 x shift)
*20 x 2 Dedicated keys
Speed Dial No 200 locations(00~199)
include 1-touch dials
TAD I/F No Yes
Tone/Pulse No Selectable in Technical Mode
Pause No Yes
Auto Redial No Yes
Last Number Redial No Yes
Distinctive Ring No Yes
Caller ID No No
External Phone Interface No Yes
Report & Tx/Rx Journal No Yes
List Print out Confirmation No Yes
Help List No No
Auto Dial List No Yes
System Data List No List all user setting
Sound Control Ring Volume No Yes(Off, Low, MED, HIGH)
Key Volume No Yes(On, Off)
Alarm Volume No Yes(On, Off)
Speaker No Yes(On, Off, Comm)
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Specifications
3.5 Fax Specification

Fax Compatibility No ITU-T G3

Communication System No PSTN/PABX
Modem Speed No 33.6Kbps
TX Speed No 3sec
Compression No MH/MR/MMR/JPEG
Color Fax No Yes(Send Only)
ECM No Yes
Resolution Std No 203*98dpi
Fine No 203*196dpi
S.Fine No 300*300dpi
Scan Speed Std No 2.5 sec/ LTR
(ADF) Fine/S.Fine No 5 sec/ LTR
Rx fax duplex print out No No
Multiple page scan speed No 14ppm/LTR, Std mode
Receive Mode No Fax, TEL, Ans/Fax, DRPD
Memory Capacity No 4MB
Optional Memory No No
Max locations No 199 locations
to store to
1 Group Dial
Fax Forward No Yes(On/Off)
Broadcasting No up to 209 locations
Cover page No Yes
Delayed fax No Yes
Memory RX No Yes
Functions Voice Request No No
TTI No Yes
RTI No Yes
Polling No No
Earth/Recall No No
Auto Reduction No Yes
F/W Remote No Yes
upgrade
Junk Fax barrier No Yes
Secure Receive No Yes
Memory Back-up No Yes, Max. 43hours
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Specifications
3.6 Other Specification

Network Option Yes (Standard)

Protocol SPX/IPX, TCP/IP, Ethertalk, SNMP, HTTP 1.1, DLC/LLC
Operating System MS Windows 98/2000/XP/NT/Me, MAC
(English only, no status monitor, web download only)
Paper Handling Capacity( 20lbs) Main Tray 250sheets
Bypass 50 Sheet
Optional Cassette 250sheets
Output Capacity Face Down: 150Sheets/20lb Face Up: 1Sheet
Paper Handling Output Control Face down/Face up
(Continued) Paper Size Main Tray A4, Letter, Legal, Folio, Executive, B5
Bypass Bypass:Envelope 63/4, 73/4, #9, #10, DL, C5, B5
Paper Weight Main Tray 16~24 lb.
Bypass 16~43 lb.
Paper Path Standard output Bottom to Middle Front (FIFO)
Straight Through Face up, Single Sheet
Paper Size Max 216 x 356mm (8.5"x14")
Min 76 x 127mm (3"x5")
ADF Paper Weight 12.5 ~ 28lb
Capacity 50 sheets
Document Size 142mm - 216mm (5.6" - 8.5")
Widtth
Document Size 148 mm - 356mm (5.8" - 14.0")
Length
Jam Rate Cassette, 2nd Feeder 1/2000
ADF 1/1000
Multi_Feeding Cassette, 2nd Feeder 1/1000
Rate ADF 1/500
Printing Skew Top 1.5/177.8mm (1st Tray)
2.0/177.8 (2nd Tray)
Side 2/243.5mm (1st Tray)
2.5/243.5mm (2nd Tray)
Copy Skew Top 2.5/190mm (1st Tray)
3.0/190mm (2nd Tray)
Side 3.5/277mm (1st Tray)
4.0/277mm (2nd Tray)
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Specifications
Software Compatibility DOS No

Win 3.x No
Win 95 No
Win 98 Yes
Win ME Yes
Win NT 4.0 Yes
Win 2000 Yes
Win XP Yes
Mac English only web version
Linux No
WHQL MFP Yes for 2000 & XP
Driver Printer GDI, PCL6, PCL5e (Std.), PostScript Level3 (Std.)
TWAIN Yes
WIA Yes
RCP Yes
PC-FAX Yes (through PC modem and Fax S/W)
Consumables Type One Piece Type
How to install Front door open and front loading
Toner Life Initial 3Kpages (5% ISO Test Pattern) running Standard
3Kpages High yield : 5K pages
Level Sensor No
Toner Count Yes (Dot Counter)
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Specifications
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Summary of Product
4
4. Summary of Product
This chapter describes the functions and operating principal of the main components.
4.1 Printer Components

4.1.1 Front View
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Summary of Product
4.1.2 Rear View
* This wireless network antenna is not supplied with the machine. It is an option that must be purchased and
installed separately. (Option Function)
** The network port is not fitted as standard on the machine. You can purchase an optional Network Card and
install it separately.
*** If your country has a different telephone connection system, this socket may be blocked.
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Summary of Product
4.1.3 Control Panel (SCX-4720F)
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Summary of Product
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Summary of Product
Control Panel (SCX-4520)
Adjusts the brightness of the documents for

the current copy job.
1
Selects the document type for the current
copy job.
Allows you to access a list of your PC software
programs that an image can be scanned to.
2 You must create the scan list using the
S Samsung software (Printer Setting Utility)
C provided with this machine.
A Also allows you to scan and save documents in
N a USB flash drive, and manage it when it is
inserted into the USB port of your machine.
See User Guide Chapter 10, Installing a USB
Flash Drive.
Displays the current status and prompts
during an operation.
3
Turns on when the toner cartridge is empty.
Uses to scroll through the available options for

the selected menu item.
Confirms the selection on the display.

4
Enters Menu mode and scrolls through the
menus available.
Sends you back to the upper menu level.
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Summary of Product
Stops an operation at any time.

In Standby mode, clears/cancels the copy
options, such as the darkness, the document
4 type setting, the copy size, and the number of
copies.
Starts a job.
Selects the number of copies.
Allows you to use special copy features, such

as Clone, Collation, Auto Fit, 2Sides on 1pg, 2/
5
4 Up (multiple pages on a sheet), and Poster
copying.
Makes a copy smaller or larger than the original.
Allows you to save on toner by using less

6
toner to print a document.
Allows you to directly print files stored on a USB

7 flash drive when it is inserted into the USB port
in front of your machine.
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Summary of Product
4.2 System Layout

The SCX-4720F/4520 is roughly made up Main Control part, Operation Panel part, Scanner part, Line Interface
part and Power part. Each Part is separated Module which focus on common and standard design of different
kind products. main control part adopting Fax & LBP Printer exclusive Controller is composed of 2 CPU and
1 Board. Scanner part is composed of ADF and Platen and is connected with Main by Harness.
4.2.1 Feeding section

There is a universal cassette which automatically loads paper and the manual feed which supplies paper single
sheet at a time. The cassette has a friction pad which separates paper to ensure single sheet
feeding, and it has a sensor, which checks when the paper tray is empty.
- Feeding Method: Universal Cassette Type

- Feeding Standard: Center Loading
- Feeding Capacity: Cassette-250 sheets (75g/m2, 20lb paper standard)
Manual 1 sheet (Paper, OHP, Envelop, etc.)
- Paper detecting sensor: Photo sensor
- Paper size sensor: None
4.2.2 Transfer Ass’y

This consists of the PTL (pre-transfer lamp) and the Transfer Roller. The PTL shines a light onto the OPC drum.
This lowers the charge on the drum’s surface and improves transfer efficiency.
The transfer roller transfers toner from the OPC drum surface to the paper.
- Life expectancy: Over 60,000 sheets (at 15~30°C)
4.2.3 Driver Ass’y

- Gear driven power unit. The motor supplies power to the paper feed unit, the fuser unit, and the toner
cartridge.
4.2.4 Fixing Part(Fuser)

- The fuser consists of the Heat Lamp, Heat Roller, Pressure Roller, Thermistor, and Thermostat. It fixes toner to
the paper using pressure and heat to complete the printing job.
4.2.4.1 Temperature-Intercepting Device (Thermostat)

The thermostat is a temperature sensing device, which cuts off the power to the heat lamp to prevent
overheating fire when the heat lamp or heat roller overheats.
4.2.4.2 Temperature Detecting Sensor (Thermistor)

The Thermistor detects the surface temperature of the heat roller, this information is sent to the main processor
which uses this information to regulate the temperature of the heat roller.
4.2.4.3 Heat Roller

The surface of the Heat Roller is heated by the Heat Lamp. As the paper passes between the Heat and Pressure
rollers the toner is melted and fixed permanently to the paper. The surface of the roller is coated with Teflon. This
ensures that toner does not adhere to the roller surface.
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Summary of Product
4.2.4.4 Pressure roller

The Pressure Roller mounted under the heat roller, it is made of a silicon resin, and the surface of the roller is
coated with Teflon. This ensures that toner does not adhere to the roller surface.
4.2.4.5 Safety Features

• To prevent overheating
- 1st protection device: Hardware cuts off when overheated
- 2nd protection device: Software cuts off when overheated
- 3rd protection device: Thermostat cuts off mains power to the lamp.
• Safety device
- Fuser power is cut off when the front cover is opened
- LSU power is cut off when the front cover is opened
- The temperature of the fuser cover's surface is maintained at less than 80ºC to protect the user and a caution
label is attached where the customer can see it easily when the rear cover is opened.
4.2.5 Scanner
This image is read using a photosensitive sensor. It consists of a CCD module, Connection board, ADF board,
AFE (Analog Front End), Image Processor (Located in CPU), platen glass and ADF mechanism.
• CCD Module Specification

1.Resolution: 600dpi/A4
2.Maximum scan wide: 8.5”
3.Color filter: Red, Green, Blue
4.Output channel: 3 channels (R, G, B)
5.Effective pixel: 5,400 pixel *3
6.Voltage: 24V & 5V
7.Pre-heating time: Maximum 30 seconds (70% of light output reached)
8.The life span of a lamp: 30,000 hours (25oC)
• Image Processor Specification

1.Operating frequency: 66MHz
2.Image sensor interface: 200/300/600 dpi CIS or CCD
3.Line time: Copy, FAX, Binary (Lineart, Halftone) PC Scan: 1.5ms/Line Color PC Scan (Grey, 256 Color,
True Color): 4.5ms/Line
4.A/D conversion: 10bit conversion
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Summary of Product
4.2.6 LSU (Laser Scanner Unit)

This is the core of the laser printer. It converts the video data received from the computer into an electrostatic
latent image on the surface of the OPC drum. This is achieved by controlling the laser beam and exposing the
surface of the OPC drum to the laser light. A rotating polygon mirror reflects the laser light onto the OPC and each
side of the mirror is one scan line. The OPC drum turns as the paper feeds to scan the image down the page.
The /HSYNC signal is created when the laser beam from LSU reaches the end of the polygon mirror and this
signal is sent to the controller. The controller detects the /HSYNC signal to adjust the vertical line of the image on
paper. In other words after the /HSYNC signal is detected the image data is sent to the LSU to adjust the left margin
on the paper.
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Summary of Product
4.2.7 Toner Cartridge

The toner cartridge is an integral unit containing the OPC unit and toner unit. The OPC unit consists of the
OPC drum and charging roller, and the toner cartridge unit consists of the toner, supply roller, developing
roller, and blade (Doctor blade)
- Developing Method: Non magnetic 1 element contacting method

- Toner: Non magnetic 1 element shatter type toner
- The life span of toner: 3,000 sheets (IDC Pattern/A4 standard)
- Toner remaining amount detecting sensor: Yes
- OPC Cleaning: Electrostatic process
- Management of waste toner: Collect the toner using a Cleaning Blade
- OPC Drum protecting Shutter: Yes
- Classifying device for toner cartridge: ID is classified by interruption of the frame channel
-430V
-950V
-580V
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Summary of Product
4.3 Main PBA

The Engine Board and Controller Board have been integrated into a single PBA. This consists of the CPU,
printer scanner and line control functions. The CPU functions as the bus controller, I/O handler, motor driver
and PC inter-face. The main board sends the Current Image Video data to the LSU and manages the
Electrophotographic printing process. Circuits on the PBA drive include the main motor (paper feed,
cartridge, fuser), clutch driver, pre-transfer lamp driver, heat-lamp driver, CCD driver, scan motor driver,
modem and fan driver.
The signals from the paper feed jam sensor and paper empty sensor are inputted to the main board from
the power supply PBA..
10 19
11 16
12 1
3 5
20
4 6
25
26
21 2
22
27
15
23 18 7 8
13 24
14 15 17
28
9
29
LIN E T RAN SCE IV ER

1 IMAG E P RO CE SS OR(CIP4 E ) U 1 0 11 M OT OR DRIV ER(T E A3 7 1 8 S) U 5 21
(7 4 LV X1 6 1 2 8 4 ) U 3 6
2 P ROCE SSOR AS IC(S PGP m) U3 5 12 M OT OR DRIV ER(T E A3 7 1 8 S) U 9 22 VE DIC X- T AL (1 9 .6 MH z) OS C3
FL ASH ME MORY
3 13 U SB 2 .0 (N ET 2 2 72 ) U5 0 23 CPU X- T AL (1 2 MH z) OSC8
CODE - H IGH (2 9 LV1 6 0 DB) U2 3
FL ASH ME MORY M ODEM X- T AL (2 8 .2 2 4 M Hz)
4 14 CMO S- LOG IC(7 4 H CT 2 7 3 ) U5 8 24
CODE - LO W( 2 9L V1 6 0 DB) U 3 0 OSC6
FL ASH ME MORY
5 15 CMO S- LOG IC(7 4 H CT 2 7 3 ) U5 9 25 U SB HOS T X- T AL (6 MH z) OSC9
P CL 6 - HIGH (2 9 LV1 6 0 DB) U 2 4
FL ASH ME MORY
6 16 P ANAS ONIC(3 V) BAT 2 26 P S3 DIMM CN1 0
P CL 6 - LOW(2 9 L V1 6 0 DB) U3 1
7 SDRAM (K4 S2 8 1 6 3 2 E) U4 5 17 VA RT A (3 .6 V) BA T 1 27 RAM DIM M CN 1 2
8 SDRAM (K4 S2 8 1 6 3 2 E) U4 6 18 FP GA(E X6 4 - FT Q 6 4) U4 4 28 J ACK U SB J1
A/D CONVE RT E R(AF E- CIP 4 E)

9 MODEM(FM 3 3 6 ) U6 2 19 29 J ACK DIN CN 1 7
U3
10 SRAM (K6 R1 0 1 6 VID) U2 20 U SB HOS T (T DO T G2 4 2 ) U 14 8 30
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Samsung Electronics
Summary of Product
4.3.1 ASIC
Use 32Bit RISC Processor, ARM946ES,which is exclusive controller to execute Printer & FAX Function and to
execute operation block by flash memory within system program, and to control whole system.
• Main function block

• Completely Integrated System for Embedded Applications,
• 32 Bit Risc Architecture, Efficient and Powerful ARM9 Core.
• LSU Interface Module for Interfacing PVC or HPVC with LSU
• 2 Channel General Purpose DMA Controller for High Speed I/O
• Dual Memory Bus Architecture
• Operation Frequency : AHB Bus: 60MHz, Internal System Bus: 120MHz
• Operation Voltage : 3.3V
• POWER ON RESET TIME : Below 5.6ms
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Summary of Product
4.3.2 Memory
The SCX-4720F/4520 has Flash ROM and DRAM memory units. There are 2 SODIMM sockets to enable extra DRAM
or FlashROM (Postscript Option) to be fitted.
On Domestic 9Korean) models additional Mask ROM is also fitted: to store domestic Fonts such as PCL Font and
KS5895, KSSM etc.
- Capacity : 32MByte
- Access Time : 100nsec
4.3.3 Flash Memory

Record System Program, and download System Program by PC INTERFACE.
FAX for Journal List, and Memory for One Touch Dial, Speed Dial List.
- size : 4M Byte
- Access Time : 70 nsec
4.3.4 SDRAM
SDRAM is used as Swath Buffer in Printing, Scan Buffer in Scanning, ECM Buffer in FAX receiving, and System
Working Memory Area
- size 32MB : 32Mbyte(Basic).
- Max Frequency : 133MHz
- store Fax Receive Memory Data by using Battery
4.3.5 Battery Backup (SCX-4720F only)

Backup power is provided by a 3.6V rechargeable Lithium battery. It provides power to the SD-RAM to retain any
faxes in memory when main power is lost. Typically backup power will last up to 43 hours. The battery requires 48
hours to charge from empty.
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Summary of Product
4.3.6 Sensor input circuit

1) Paper Empty Sensor
The Paper Empty sensor (Photo Interrupter) on the SMPS/HVPS PBA (CON2-2) is monitored by the
CPU on signal (nP_EMPTY). When the cassette is empty the printer displays a message on the LCD
panel.
2) MP Sensing
Presence of paper in the MP tray is detected by operation of the MP Sensor (Photo Interrupter) on the
SMPS/HVPS PBA (CON2-14). The CPU monitors signal(MP_EMPTY) to recognize paper in the MP, and
paper is fed from MP if there is paper present.
3) Paper Feed Sensor, (Toner Cartridge Sensor)

When paper passes the actuator on the feed sensor (CON2-1), it is detected by the Photo interrupter. sig-
nal(nP_FEED) monitored by the CPU and this signal starts the process of creating the image after certain
delay time If the feed sensor is not detected within 1 sec. after paper is fed, a paper Jam0 occurs.
(Displayed on the LCD panel).
When a toner cartridge is inserted it also operates the Paper Feed sensor. A message is displayed on the
LCD if no cartridge is detected.
4) Paper Exit Sensor

This detects that paper exits cleanly from the Machine using an exit sensor (CON2-24) on the engine
board and actuator on the frame. The monitors signal (P_EXIT) and detects the on/off time of the exit
sensor and if jam status is detected then JAM2 is displayed the on the LCD panel.
5) Cover Open Senser

The Cover open sensor actuator is located on the front cover and the senor is in the main frame. When the
front cover is opened the +24V supplies to the DC fan, solenoid, main motor, polygon motor part of LSU,
HVPS that are cut off. The CPU monitors signal (COVER_OPEN) to recognize when the cover is opened.
6) DC FAN / SOLENOID Driving

It is driven by a transistor and controlled by signal (FAN (SMPS, CON2-23)) bit of the CPU.
When it is high the fan is activated by turning on the TR, and it is off when the sleep mode is selected.
There are two solenoids and these are driven by the Paper Pick-up and MP signals. The drive time is
300ms. The diode protects the driving TR from the Back-EMF pulse which is generated when the sole-
noid is de-energized.
7) Motor Driving
The motor driving circuit is activated when the Driver IC is enabled. An A3977 (Motor driver IC) is used in
this case. The resistance Rs value of sensing and the voltage value of the V reference can be changed
by the motor driving voltage value.
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Summary of Product
4.4 SMPS & HVPS

The SMPS and HVPS are on one integrated board.
The SMPS supplies the DC power to the system. It takes either 110V or 220V and outputs the +5V, +12V and
+24V supplies to the main and other PBAs.
The HVPS creates the high voltage of THV/MHV/Supply/Dev and supplies it to the toner cartridge. The CPU is
used to modify some of these voltage settings to provide the ideal voltages to create the image.
The HVPS part uses the 24V and outputs the high voltage for THV/MHV/BIAS and the outputted high voltage is
supplied to the toner, OPC cartridge and transfer roller.
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Summary of Product
4.4.1 HVPS(High Voltage Power Supply)

1) Transfer High Voltage (THV+)
- Function : It is this voltage that transfers toner from the OPC Drum to the paper.
- Output voltage : +1300V DC±20V
- Error : IF THV (+) is not present, low density printing occurs due to toner on the OPC Drum not being
transferred to the paper. It is possible that waste toner over-flow can occur if this condition
persists. Ghost images may appear which repeat at 76mm intervals.
2) Charge Voltage (MHV)

- Function : It is this voltage that charges the surface of the OPC to -900V ~ -1000V.
- Output voltage : -1550V DC ± 50V
- Error : IF MHV is not present toner then since the OPC drum surface has no charge toner is attracted to
the whole OPC surface. A black page is printed out when this happens.
3)Cleaning Voltage (THV-)

- Function : It removes toner contamination from the rear side of the paper by sending (-) polarity to the
transfer roller forcing toner to transfer back to the to OPC drum.
- Output Voltage : -1200V, +300V/-150V
- Error : Smudges and toner contamination on the reverse side of the printed page.
4) Developing Voltage (DEV)

- Function: It is this voltage that develops toner with on to the section of the OPC drum surface exposed
by the LSU
(Laser Scanning Unit).
* When printing the exposed voltage on the OPC is -180V, unexposed is -900~-1000V, and the exposing
voltage on the DEV is -430V. Therefore toner with (-) polarity is developed onto an exposed
section of the OPC.
- Output voltage: -430V DC ± 20V
- Error: a) If DEV is GND, print density gets extremely low.
b) When DEV is floating due to poor connection between the frame and cartridge contacts etc.,
print density gets extremely high.
5) Supply Voltage (SUP)

- Function: It is this voltage that supplies toner to the developing roller.
- Output voltage: : -580V DC ± 50V (Use ZENER, DEV Gear)
- Error: a) When SUP is GND print density gets extremely low.
b) If SUP is floating due to poor connection between the frame and cartridge contacts etc. density
gets extremely low such that it is hard to see toner with the eyes
6) OPC Ground ZENER Voltage

- Function: It is this voltage that prevents image contamination under low temperature and low humidity
environment conditions.
- When a set prints without an output voltage, -130V DC ± 15V is maintained on OPC ground. (-103V
ZENER diode is connected to OPC ground)
- Error type: a) When the ZENER diode is - 0V there is no serious image problem in general environ-
ment, but in low temperature and low humidity environments it is possible that contamination
can occur on the entire image
b) When the ZENER diode is disconnected a blank page is printed out. (It is the same when
a ZENER diode is disconnected from OPC ground.)
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Summary of Product
4.4.2 SMPS (Switching Mode Power Supply)

This is the power source for the whole system. It is an independent module so that it is possible to use it for
common use. It is mounted at the bottom of the set.
It consists of the SMPS section, which supplies the DC power to drive the system, and the AC heater control part,
which supplies the power to the fuser. The SMPS has four output channels (+5V, +24V and 24VS).
There are three kinds of power, 120V exclusive (America), 220V exclusive (Europe), and 220V for China (nations
with unstable power supply).
1) AC Input
> Input Rated Voltage : AC 220V ~ 240V AC 120V / AC 220V(EXP version)
> Input Voltage fluctuating range : AC 198V ~ 264V AC 90V ~ 135V / AC 198V ~ 264V
> Rated Frequency : 50/60 Hz
> Frequency Fluctuating range : 47 ~ 63 Hz
> Input Current : Under 5.0Arms / 2.5Arms (When the fuser lamp is off and input / output voltages are in range)
2) Rated Output Power
NO ITEM CH2 CH3 Remark

1 CHANNEL NAME +5V +24.0V
2 CONNECTOR PIN CON 23 CON 23
5V PIN: 3, 4 24V PIN:11,12,13
GND PIN: 5, 6, 7 GND PIN:9,10, 18
3 Rated Output +5V & 5% +24V & 10%
(4.75 to 5.25V) (21.6 to 26.4V)
4 Max. Output Current 0.14 A 2.0 A
5 Peak Loading Current 0.14 A 2.5 A 1ms
6 RIPPLE NOISE 100mVp-p Under 500mVp-p
Voltage
7 Maximum Output Power 0.35W 48W
8 Peak Output Power 0.7W 60W 1ms
9 Protection for short circuit -
and current overload
3) Power Consumption
NO ITEM CH2 (+5V) CH3 (+24V) Remark
1 Stand-By 0.07A 0.4 A AVG:55 Wh
2 PRINTING 0.14A 2.0 A AVG 350 Wh
3 Sleep-Mode 0.01A 0.4A AVG : 20 Wh
4) Length of Power Cord : 1830 ± 50mm
5) Power Switch : Fitted
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Summary of Product
6) Feature
- Summary of Product
- Insulation resistance : over 50M Ω (at DC500V)
- Insulating retest pressure : Must be no problem within 1min. (at 1500Vzc, 10mA)
- Leakage current : under 3.5mA
- Operating current : under 40A peak (at 25°c, Cold start) Under 60A peak (in other conditions)
- Rise Time : Within 2Sec
- Fall Time : Over 20ms
- Surge : Ring Wave 6KV-500A (Normal, Common)
7) Environment Condition
- Operating temperature range : 0°C ~ 40°C
- Storage temperature range : -25°C ~ 85°C
- Storage humidity range : 30% ~ 90% RH
- Operating atmospheric pressure range : 1
8) EMI Requirement : CISPR ,FCC, CE, MIC, C-Tick,
9) Safety Requirement
- IEC950, C-UL, TUV,Semko,iK,CB, CCC, EPA,
4.4.3 Fuser AC Power Control

The Fuser (HEAT LAMP) is heated using AC power. The AC power is controlled by a Triac (THY1), a
semiconductor switch. 'On/Off control' is achieved when the gate of the Triac is turned on/off by a Photo
triac (PC1), this is an insulting part.
In the other words the AC control part is a passive circuit. It turns the heat lamp on/off by taking a signal
from the engine control section. When the 'HEATER ON' signal is activated by the engine the LED of PC1
(Photo Triac) flashes. The flashing light causes the Triac (PC1) to switch and a voltage is supplied to the
gate of Triac THY1. As a result AC current flows in the heat lamp, and heat is produced.
On the other hand, when the signal is off, PC1 is off, the voltage is cut off at the gate of Triac THY1, this
Triac is therefore off, and thus the heat lamp is turned off.
1) Triac (THY1) feature

- 12A, 600V SWITCHING
2) Phototriac Coupler (PC3)

- Turn On If Current : 15mA ~ 50mA(Design: 16mA)
- High Repetive Peak Off State Voltage : Min 600V
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Summary of Product
4.5 Engine F/W

4.5.1 Feeding
If feeding from the cassette the drive of the pickup roller is controlled by controlling the pick-up solenoid. The on/off
of the solenoid is controlled by controlling the general output port or the external output port. If feeding from the
manual feeder the set decides to feed the paper according to the operation of the manual sensor, and by driving
the main motor, insert the paper in front of the feed sensor. When paper moves the occurrence of a paper jam is
judged as below.
4.5.1.1 Jam 0 – Jam in Feed area

• After a page was picked up, paper did not enter the unit due to a paper misfeed.
• After a page was picked up, paper entered but it did not reach the feed sensor in certain time due to slip, etc.
• After a page was picked up, if the feed sensor is not on try to pick up again. After retrying if the feed
sensor is still not on after certain time, it is Jam 0.
- this indicates that the leading edge of the paper doesn't pass the feed sensor within a certain time.
• Even though the paper reaches the feed sensor, the feed sensor does not turn on.
- this indicates that the leading edge of the paper already passed the feed sensor or that the sensor is fauty.
4.5.1.2 Jam 1 – Jam inside the print engine

• After the leading edge of the paper passes the feed sensor, the trailing edge of the paper does not pass the feed
sensor within certain time. (During this time the feed sensor cannot be Off)
• After the leading edge of the paper passes the feed sensor, the paper does not reach the exit sensor within cer-
tain time. (The exit sensor cannot be On during this time)
- There is already paper between the feed sensor and the exit sensor.
4.5.1.3 Jam 2 – Jam in the Exit area

• After the trailing edge of the paper passes the feed sensor the trailing edge of the paper does not pass the exit
sensor within certain time.
4.5.2 Drive
The main motor drives the paper feed, developing unit and the Fuser It is driven by software which controls the
acceleration, constant speed and deceleration profiles. The Motor is managed with an A3977 driver IC and con-
trolled by step and enable signals from the CPU.
4.5.3 Transfer
The charging voltage, developing voltage and the transfer voltage are controlled by PWM (Pulse Width
Modulation). Each output voltage is changeable according to the PWM duty cycle. The transfer voltage used when
the paper passes the transfer roller is decided by environment recognition. The resistance value of the transfer
roller changes due to the surrounding environment in the room or within the set, this change in resistance in turn
changes the value of the voltage due to loading. This voltage is fed back into the set through the A/D converter.
Based on this fed back value the PWM cycle is changed to maintain the required transfer voltage
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Summary of Product
4.5.4 Fusing
The temperature of the heat roller's surface is detected according to the resistance value of the thermistor.
The thermistor resistance is measured using the A/D converter and thus the CPU can determine the
temperature of the heat roller. The AC power is controlled by comparing the target temperature to the value
from the thermistor. If the value from the thermistor is out of the controlling range while controlling the fusing
process, the error stated in the table occurs. (For the domestic model, the Q-PID method has been applied.)
4.5.4.1 Error Type
Error Description
Open heat error When warming up, it has been lower than 68 °C over 25 sec
Lower heat error • Standby:

It has been lower than 100°C over 25 sec
• Printing:
- 2 consecutive pages: it has been lower than 145°C over 5 sec
- 3 consecutive page: it has been 40°C lower than the fixed fusing temperature over 4 seconds.
Over heat error It has been higher than 220°C over 3 seconds
4.5.5 LSU
The LSU consists of the LD (Laser Diode) and the polygon motor control. When the printing signal occurs,
the LD is turned on and the polygon motor is enabled. When the light sensor detects the beam, Hsync occurs.
When the polygon motor speed becomes a normal, LReady occurs. If these two conditions are satisfied, the
status bit of the LSU controller register becomes 1 ant the LSU is judged to be ready. If the two conditions
are not satisfied, the error shown in the table below occurs.
Error Description
Polygon motor error When the polygon motor’s speed doesn’t become a normal
Hsync error The polygon motor’s speed is normal, but the Hsync signal is not created.
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Summary of Product
4.6 OPE PBA

The OPE board consists of various function keys and an LCD to display set status and operator messages.
A MICOM (HOLTEC HT48R50) drives the LEDs and LCD. Communication between the OPE and the CPU
on the main board is serial (related signals are /Reset, TXD, and RXD).
4.7 USB Host

The USB Host PBA provides power to the USB connector to enable a USB Memory drive to be used in conjunction with
the USB Direct printing and Scan to USB functions.
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Summary of Product
4.8 Fax Section
4.8.1 Modem
• Group3 Facsimile Modem (Entire FM336/314 Family)
• External Handset Support (not implemented on SCX4720F)
• Requires Discrete Line Interface Unit (LIU )
• V.34 Half-Duplex Mode
• V.90 PCM/V.34 Duplex Data Modes
/RTS XTLI
/CTS XTLO Crystal

TXD
OR
TDCUK CLKIN
XTCLK Oscillator
V24 /RLSD
Interface RXD RIN
/RDCLK TXA1 telephone

line
/DTR TXA2 TIP
/DSR**
Line RING
DH
Interface
/RI* RINGD
/TALK
FM336
/RD
Modem
/WR EYEXY
/CS EYESYNC Optional

/D[x:0]
Eye Pattern
EY RCLK
Generator
Host RS[4:0]
Processor IRQ
/RESET
TXRQ* SPKR Speaker

RXRQ** Amplifier
+SV
+3.3V
AGND Power Supply
DGND
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Summary of Product
4.8.2 LIU PBA

The LIU board is the Line interface unit. It consists of a Tel_line Interface circuit and Telephone circuit.
The Tel_Line circuit consists of a matching transfer to conform to the impedance of the receiving telephone line and a
circuit to isolate the fax machine from the PSTN, and a surge absorber to protect against lighting strike surges on the
incoming line.
The Telephone circuit is consists of ring detection circuit, speech circuit, external hook detection circuit, and recall circuit.
1 TRANS MATCHING T1
4 2 TRANS MATCHING T2
1 3 RELAY RE1
4 VARISTOR VAR1/VAR2
5
3 5 JACK MODULAR(TEL) MJ1
6 JACK MODULAR(EXT) MJ2
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Samsung Electronics
Summary of Product
4.8.3 Tel-Line Connection Circuit

• The Tel-Line Connection Circuit connects the fax machine to the PSTN using Tip and Ring terminals.
• Use Modular Plug : RJ-11C
• Arr1, Arr2 and Arr3 are protection components to prevent damage due to overvoltage surges, e.g. lightening.
4.8.4 Transformer Circuit

• The Transformer circuit is a line impedance matching circuit which matches the internal impedance of the fax machine
to the external -48Volt DC impedance of the PSTN system.
• The Transformer circuit insolates the fax machine electrically from the PSTN.
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Summary of Product
4.8.5 On Hook State

• DC10V ~ DC100V, DC Resistance : 5MΩ and over
• DC150V ~ DC200V, DC Resistance : 30KΩ and over
• Ring Sensitivity
- Ring detection voltage : 40Vrms ~ 150Vrms
- Ring detection frequency : 15.3Hz ~ 68Hz
- Ring detection current : 20mA ~ 100mA
• Pseudo Ring Sound

- Ring frequency : 750Hz + 1020Hz
- Ring Interrupt period : Mark/Space controlled by CPU/Modem
4.8.6 Off Hook State

• DC Resistance
- DP Dial Mode (DC 30mA) : 50 ~ 220 Ω
- DTMF Dial Mode (DC 20mA) : 50 ~ 300 Ω
- DTMF Dialing (DC 20mA) : 50 ~ 540 Ω
• Matching (Input AC Impedance) : 600 Ω±30% for 300Hz ~ 3.4KHz
• Minimum Line Current detecting Off Hook : 20mA(Handset Hook Off)

15mA(external Handset Hook Off)
• Minimum Line Current for DP Dial transmission : 20mA ~ 120mA

Product Margin : 20mA and over
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Samsung Electronics
Summary of Product
4.8.7 Signal
• Input Signal Level Range : - 0dBm ~ - 48dBm
• DP (Dial Pulse) Dial

- Make / Brake Ratio : 40 : 60
- Pulse Speed : 10 ± 0.8 pps, Minimum Pause : above 60 msec
• DTMF Signal
- Coding Format
- Transmission Level
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Samsung Electronics
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Summary of Product
MEMO
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Samsung Electronics
Precautions
5
5. Disassembly and Reassembly
5.1 General Precautions on Disassembly
When you disassemble and reassemble compo-

nents, you must use extreme caution. The close
proximity of cables to moving parts makes proper
routing a must.
If components are removed, any cables disturbed
Releasing Plastic Latches
Many of the parts are held in place with plastic

latches. The latches break easily; release them
by the procedure must be restored as close as carefully.
possible to their original positions. Before remov- To remove such parts, press the hook end of the
ing any component from the machine, note the latch away from the part to which it is latched.
cable routing that will be affected.
Whenever servicing the machine, you

must perform as follows:
1. Check to verify that documents are not stored

in memory.
2. Be sure to remove the toner cartridge before

you disassemble any parts.
3. Unplug the power cord.
4. Use a flat and clean surface.
5. Replace only with authorized components.
6. Do not excessive force on components made of

plastic, they may break.
7. Make sure all components are in their proper

position.
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Precautions
5.2 Rear Cover

1. Remove the four screws securing the Rear Cover. 3. Unclip the Face Up Cover from the Rear cover, as
shown below. Then lift the Face Up Cover out.
Face Up Cover
2. Remove the Rear Cover from the Frame Ass'y and

Scanner Ass'y.
Rear Cover
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Samsung Electronics
Precautions
5.3 Side Cover (LH, RH)
1. Before you remove the Side Cover (LH, RH), you

should remove:
- Rear Cover (see page 5-2)
2. Take out the Cassette.
Side Cover (LH)

Cassette
3. Open the front cover and remove 2 screws on the

front and 1 screw on the back. Release 3 clips under-
neath, ease the rear screw bracket over its locating
pin and pull the RH side cover to the right, taking care
not to damage the clips, to remove it from the Frame
Assembly.
Side Cover (RH)
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Precautions
5.4 Front Cover

1. Open the Front Cover. 3. Unclip the Front Cover from the Frame Ass'y. Then
remove the Front Cover, as shown below.
Front Cover
2. Remove the Toner Cartridge.
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Samsung Electronics
Precautions
5.5 Scanner Ass'y

1. Before you remove the Scanner Ass'y, you should 4. Pull up the Scanner Ass'y, as shown below.
remove:
- Rear Cover (see page 5-2) Scanner Ass'y
- Side Cover (LH, RH) (see page 5-3)
2. Remove the 2 screws securing the Scanner Ass'y, as

shown below.
5. SCX4520 only. Lift the Platen Cover upward to

remove it.
1
3. Remove the 5 connectors and the ground wire screw 3
from the main PBA as shown below.
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Precautions
6. SCX4720F. Free the Scanner Cable Harness from the 8. Release the 3 clips on the front of the OPE unit and
clips underneath the scanner and release it from the frame. remove the OPE unit as shown below, taking care to
thread the cable harness through the frame
Clips
7. Lift the front part of the COVER-OPE FRONT to

release the hook connecting the cover with the scan
assembly. <SCX-4520>
Clips
COVER-OPE FRONT
<SCX-4520>
<SCX-4720F>
COVER-OPE FRONT
<SCX-4720F>
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Samsung Electronics
Precautions
9. Remove the 4 screws securing the Scan Upper. 12. Pull up the CCD Shaft and take out the Scanner
Module.
Scanner Module
CCD Shaft
10. Unclip the Scan Upper from the Scan Ass'y by

releasing 2 clips on each side then pull the Scan
Upper upward and remove it. 13. Squeeze the spring to release the tension in the Belt
and lift from the pulleys as shown below.
Scan Upper
Spring
Belt
11. Remove the CCD Cable, as shown below.
CCD Cable
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Precautions
14. Remove the Reduction Gear and Idle Gear, as

shown below.
Gear-Reduction
Gear-Timing
Caution. Reassembling Scanner Module

1. When re-fitting the scanner belt and belt spring
take care to relocate the tension spring as close to
the right hand side of the scanner module as is
possible, as shown on the right.
2. When refitting the Scan Upper cover take care to
ensure that the cover open switch is not trapped.
Caution
Assembling Scanner Module When

re-assembling the scanner module, belt
and belt spring take care to relocate the
tension spring as close to the right hand
side of the scanner module as is possible,
as shown on the right.
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Samsung Electronics
Precautions
15. Remove the 3 screws and take out the Motor 17. Unlatch the Open Sensor and remove it, as shown
Bracket. below.
Motor Bracket
Open Sensor
16. Unplug the connector from the Open Sensor Ass'y. 18. Remove the CCD lock
Unlock
CCD Lock
Lock
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Precautions
5.6 ADF Motor Ass'y

1. Before you remove the ADF Motor Ass'y, you should 4. Release the Bush and rotate it until it reaches the slot,
remove: as shown below. Then lift the Pick-Up Ass'y out.
- Scanner Ass’y (see page 5-5)
Pick up Ass y
2. Unclip the harness from the platen cover. Remove the
2 screws securing the ADF Ass'y and remove it, taking
care to thread the harness through the frame.
Bushing
ADF Ass y
5. Remove the 2 screws securing the Upper Cover and

remove it, as shown below.
3. Remove the Open Cover, as shown below. Upper Cover
Open Cover
manuals4you.com
Caution. Before removing the ADF Motor Ass’y take

great care to note the position of the ferrite
core and the motor harness routing. When
refitting the ADF Motor Ass’y ensure that the
Caution. When working on the ADF Motor Ass’y take harness and ferrite are properly located and
care not to contaminate any of the rubber are clear of the motor fan and white bar clip.
surfaces with grease.
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Samsung Electronics
Precautions
6. Unplug the one connector and remove 5 screws

securing the ADF Motor Ass'y. Then take out the ADF
Motor Ass'y.
ADF Motor Ass y
ADF Lower Ass y
Note. It is not necessary to disassemble the ADF unit in

order to change the ADF separator pad. Simply
open the ADF cover and remove the Pickup Ass’y
(step 4 page 5.10). Then, using a pair of tweezers
or a small flat-bladed screwdriver, release the clips
on each side of the ADF Separator Pad Ass’y.
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Precautions
5.7 OPE Unit(SCX-4520)

1. Before you remove the OPE Unit, you should remove: 4. Remove the Key Pad from the OPE Cover.
2. Remove the 7 screws securing the OPE PBA from to

the OPE Cover.
OPE Cover
Key Pad
OPE PBA
3. Remove the Contact Rubber from the OPE Cover.
Contact Rubber
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Samsung Electronics
Precautions
OPE Unit(SCX-4720F)
1. Before you remove the OPE Unit, you should remove: 4. Remove the Key Pad from the OPE Cover.
2. Remove the 10 screws securing the OPE PBA from to

the OPE Cover.
OPE Cover
Key Pad
OPE PBA
3. Remove the Contact Rubber from the OPE Cover.
Contact Rubber
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Precautions
5.8 Middle Cover & Exit Roller

1. Before you remove the Middle Cover and Exit Roller, 4. Remove the Exit Gear and Bearing, as shown below.
you should remove:
- Scanner Ass'y (see page 5-5)
2. Remove the 4 screws securing the Middle Cover and

remove it.
3. Remove 2 screws securing the Controller Shield Ass’y

to the Middle Cover. Unclip the Middle Cover from the
Frame Ass'y, as shown below. Take care to release
the Shield Ass’y locating pegs and lift the Top Cover out.
Middle Cover
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Samsung Electronics
Precautions
5.9 Controller Shield Ass’y

1. Before you remove the Main PBA, you should 4. Remove 3 screws to remove the bracket from the
remove: main board.
- Side Cover(LH, RH) (see page 5-3)
Main Board
2. Remove all of the connectors and the 5 screws con-
necting the Controller Shield Assembly to the Middle
Cover and frame and remove the assembly.
Controller Shield Ass y
Bracket
3. If fitted remove the 2 screws connecting the NIC card

to the Controller Shield Assembly and remove the card.
NIC Card
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Precautions
5.10 Engine Shield Ass’y & Exit Board

1. Before you remove the Engine Shield Ass'y, you 3. Remove the 11 screws securing the Engine Shield
should remove: Ass'y and tilt to one side. Then unplug the all the
- Rear Cover (see page 5-2) HVPS/SMPS harness before removing the ass’y.
- Scanner (see page 5-5)
2. Unplug the Exit, AC and Fan connectors. Unplug the

LIU connector if fitted.
Exit Connector
Main Connector
AC Connector Engine shild Ass y
4. Remove the 2 screws to remove the exit board.

Fan Connector
Exit Board
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Samsung Electronics
Precautions
5.11 SMPS and LIU

1. Before you remove the SMPS, you should remove: 4. Remove the 3 screws securing the SMPS. Then lift
- Rear Cover (see page 5-2) the SMPS out, as shown below.
SMPS
- Engine Shield Ass’y(see page 5-16)
2. Remove the 2 screws securing the Inlet Bracket and

remove it
Inlet Bracket
3. Remove the one screw securing the Engine Shield

ground wire 5. Remove the 3 screws securing the LIU. Then lift the
LIU out, as shown below.
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Precautions
5.12 Fuser Ass'y

1. Before you remove the Fuser Ass'y, you should 4. Remove the 2 screws securing the Halogen Lamp.
remove: Then take out the Halogen Lamp from the Heat Roller
2. Unplug the two connectors from the Main PBA and

SMPS, as shown below. Then remove the 4 screws Heat Roller
securing the Fuser Ass'y and remove it.
Fuser Ass y
Halogen Lamp
5. Remove 4 screws to remove the fuser cover as

below. Remove 2 screws to remove the guide input.
3. Remove the 2 bolts securing the Thermostat. Then lift

the Thermostat out taking care not to loose the 2 nuts. Claw
Fuser Cover
Bolts
Thermostat
Nuts
guide Input
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Samsung Electronics
Precautions
6. Unwrap the Thermistor Harness, as shown below. 7. Remove the one screw securing the Thermister and
remove it, as shown below.
Thermistor
Thermistor
5.13 Fan
1. Before you remove the Fan, you should remove: 2. Unplug the connector from the SMPS and remove the
- Rear Cover (see page 5-2) one screw. Then take out the Fan.
- Side Cover (RH) (see page 5-3)
DC Fan
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Precautions
5.14 LSU
1. Before you remove the LSU, you should remove: 3. Unplug the two connectors.
- Front Cover (see page 5-4)
- Middle Cover (see page 5-14)
2. Remove the 4 screws securing the LSU and remove it.
5.15 CRUM Board

1. Before you remove the CRUM Board, you should 2. Remove the 4 screws to separate the CRUM board
remove: from the main frame as below, taking care not to loose
- Rear Cover (see page 5-2) the springs.
- Middle Cover (see page 5-14) CRUM Board
- LSU (see page 5-20)
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Samsung Electronics
Precautions
5.16 Drive Ass'y
1. Before you remove the Drive Ass'y, you should 3. Take out the Drive Ass'y, then unplug the connector
remove: from the Motor PBA, as shown below.
- Side Cover (LH) (see page 5-3)
Drive Ass y
- Shield Controller Ass’y (see page 5-9)
2. Remove the 5 screws securing the Drive Ass'y.
Drive Ass y
Caution. The six screws have numbers stamped. into

the Drive Ass’y base plate. When refitting the
Drive Ass’y tighten the screws the order they
are numbered. Only screw s numbered 1 to 5
are fitted at this stage. Screw 6 is fitted when
the Shield Controller Ass’y is refitted
5.17 Cover Mid Front
1. Before you remove the Cover Mid Front, you should 2. Remove the 4 screws securing the Cover Mid Front
remove: and release 2 clips in the center. This cover is fragile
- Rear Cover (see page 5-2) take care when removing it.
clips
Cover Mid Front
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Precautions
5.18 Transfer Ass'y

1. Before you remove the Transfer Ass'y, you should 4. Remove the transfer roller by pressing the hook
remove: securing the roller to the right using a tool.
- LSU (see page 5-20)
- Cover Mid Front (see page 5-22)
2. Remove the 3 screws securing the Transfer Earth and

remove it.
Hook
Transfer Earth
5. Unlatch the Bushing and remove it. Then lift the

Transfer Roller out, as shown below.
Transfer Roller
Bushing
3. Unplug the PTL Holder connector, then remove the

PTL Holder and PTL Lens, as shown below.
PTL Lens
PTL Holder
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Samsung Electronics
Precautions
5.19 Feed Ass'y

1. Before you remove the Feed Ass'y, you should 4. Remove the 3 screws securing the Feed Bracket and
remove: remove it.
- Scanner Ass’y (see page 5-5) Feed Bracket
- Controller Shield Ass’y (see page 5-15)
- Drive Ass’y (see page 5-20)
2. Remove the 4 screws securing the Guide Paper Front

and remove it.
5. Remove the Feed Gear2.
Guide Paper Front
Feed Gear2
3. Remove the screws on the right and left sides of the
guide paper to remove the guides and the spring as
shown below.
Screw
Spring
Guide Paper
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Precautions
6. Remove the Feed Gear1 Ass'y. 7. Pull up the Feed Roller and Feed Roller1.
Feed Roller
Feed Gear1 Ass y
Feed Roller1
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Samsung Electronics
Precautions
5.20 Pick-Up Ass'y & Solenoid

1. Before you remove the Pick-Up Ass'y, you should 4. Remove the 2 screws securing the Manual Solenoid
remove: and Pick-Up Solenoid. Then remove Manual Solenoid
- Rear Cover (see page 5-2) and Pick-Up Solenoid.
- Controller Shield Ass,y (see page 5-15)
- Engine Shield Ass,y (see page 5-16) Pick Up Solenoid
- Drive Ass'y (see page 5-20)
- Feed Ass’y (see page 5-23)
2. Remove the Pick-Up Gear Ass,y.
Manual Solenoid
Pick up Gear Ass y
5. To replace the pick up roller, move the stopper secur-

ing the sponge-roller to the right and then turn the
sponge-roller to remove it from the shaft.
Stopper
Shaft
Sponge Roller
3. Take out the Pick-Up Ass'y, as shown below.
When replacing either the MP pick up roller or main

cassette pick up roller only, it is possible to do this by
turning the set over after removing the cassette and
the processor. See page 5-26
Bush
1
2
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Samsung Electronics
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Precautions
6. It is a simple matter to replace the MP Pickup b) In order to replace the MP Pickup Roller
Roller and the main cassette Pickup Roller 1) Release the white catch and slide the locking
without dismantling the set. piece as far to the side as possible.
In both cases first remove the main paper 2) Slide the white collar as far to the side as
cassette, toner cartridge and front cover. possible.
3) Slide the Pickup Roller as far as possible to
a) In order to replace the main cassette Pickup the side, until it is free from the white collar on
Roller the other end.
1) Turn the set upside down 4) Rotate the Pickup Roller around the drive
2) Release the white catch and slide the locking shaft until it can be removed.
piece as far to the side as possible.
3) Slide the white collar as far to the side as
possible.
4) Slide the Pickup Roller as far as possible to
the side, until it is free from the white collar on
the other end.
5) Rotate the Pickup Roller around the drive
shaft until it can be removed.
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Samsung Electronics
Alignment & Adjustments
6
6. Alignment and Adjustments
This chapter describes some of the main service procedures including:
Using the EDC mode; Clearing paper jam and test patterns.
Much of this chapter is also included in the user's guide.
6.1 Paper path
Scanner Part
ADF-Roller
Pickup-Roller
Doc-Paper(30Sheets)
ADF-Idle Roller
Sensor-R gi
Sensor-Regi
Sensor-Doc
Exit-Roller
Feed-Roller Sensor-Scan
Sensor-Scan
White-Sheet
hite-Sheet
CCD-Module
Engine Part
4 L S U
Fuser CR
Toner Cartridge
DR
7 PR
OPC SR 2
PTL
TR 6 FR 8
K /R
5 P IC
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Samsung Electronics
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6.1.1 Copy & Scan Document Path

Scanner Part
3 2
1 1 Doc. Paper (50 Sheets)
2 Pickup Roller
5 4
3 ADF Roller
7 6
4 Sensor - Doc.
White-Sheet
8
5 Sensor - Regi
6 Sensor - Scan
CCD-Module
7 Feed Roller
8 Exit Roller
6.1.2 Printer Paper Path
1) After receiving a print command, the printer feeds paper from the main cassette or manual feeder as required.
2) The paper being fed passes the paper feed sensor. (Jam 0 occurs if the sensor is not operated within a certain time)
3) Having passed the paper feed sensor the paper moves to the paper exit sensor via printing process. (Jam 1
occurs if the sensor is not operated within a certain time)
4) The paper then passes through the paper exit sensor and out of the set. (Jam 2 occurs if the trailing edge of the
paper does not pass the exit sensor within a certain time of the paper leading edge activating the exit sensor)
Engine Part
3
L S U
Fuser CR
Toner Cartridge
DR
7 PR
OPC SR 2
PTL
TR 6 FR
4
K /R
5 P IC
1 Paper Input (Cassette) 5 Paper Empty Sensor (Cassette)

2 Paper Input (Manual Feeder) 6 Paper Feeding Sensor
3 Paper Out (Face Down) 7 Paper Exit Sensor
4 Paper Empty Sensor (Manual)
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Samsung Electronics
6.2 Clearing Paper Jams

Occasionally, paper can be jammed during a print job. Some of the causes include:
• The tray is loaded improperly or overfilled.
• The tray has been pulled out during a print job.
• The front cover has been opened during a print job.
• Paper was used that does not meet paper specifications.
• Paper that is outside of the supported size range was used.
If a paper jam occurs an error message appears in the LCD display. Find and remove the jammed paper.
If you don't see the paper, open the covers.
Do not use a tweezers, pincers or other metal tools when clearing a paper jam.
This could damage the internal mechanism causing print quality problems or possibly electrical shock.
L S U
ADF-Roller
Pickup-Roller
Doc-Paper(30Sheets)
Fuser CR
Toner Cartridge
DR
EXIT OPC SR
ADF-Idle Roller Sensor PR
PTL Feed MP Sensor
TR Sensor FR
Sensor-Regi
Sensor-Doc
K /R
Exit-Roller
Feed-Roller P IC
Sensor-Scan
Sensor-Scan
Empty Sensor
White-Sheet
Document Jam Paper Jam0

(in the ADF area) (in the paper feed area)
L S U
L S U
Fuser CR
Toner Cartridge
DR Fuser CR
Toner Cartridge
EXIT OPC SR
Sensor PR
DR
PTL MP Sensor EXIT OPC SR
Feed Sensor PR
TR Sensor FR
PTL Feed MP Sensor
TR Sensor FR
K /R
P IC
Empty Sensor
K /R
P IC
Empty Sensor
Paper Jam1 Paper Jam2

(in the fuser area or around the toner cartridge) (in the paper exit area)
L S U
Fuser CR
Toner Cartridge
DR
EXIT OPC SR
Sensor PR
PTL Feed MP Sensor
TR Sensor FR
K /R
P IC
Empty Sensor
MP Tray Jam
(in the manual feed area)
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6.2.1 Clearing Document Jams

If a document jams while it is feeding through the ADF (Automatic Document Feeder),“DOCUMENT JAM ”
appears on the display.
6.2.1.1 ADF Input Misfeed

1) Open the ADF top cover. 3) Close the ADF top cover. Then load the documents
back into the ADF.
NOTE : To prevent document jams, use the document

glass for the thick, thin or mixed documents.
2) Pull the document gently to the right and out of the ADF.
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Samsung Electronics
6.2.1.2 ADF Exit Misfeed

1) Open the document cover and turn the release knob to remove the misfed documents from the exit area.
2) Close the document cover.Then load the documents back into the ADF.
6.2.1.3 ADF Roller Misfeed

1) Open the document cover. 2) Turn the release knob so that you can easily remove
the misfed document, and remove the document
from the ADF or the feed area by carefully pulling it
towards the right by using both hands.
3) Close the document cover. Then load the documents

back into the ADF.
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6.2.2 JAM0 (In the Paper Feed Area)

1) Open and close the front cover.The jammed paper 4) Insert the paper tray into the machine until it snaps
automatically exits the machine. into place.
If the paper does not exit,continue to Step 2.
2 Pull the paper tray open.
5) Open and close the front cover to resume printing.
3) Remove the jammed paper by gently pulling it

straight out.
If there is any resistance and the paper does

not move when you pull or if you cannot see
the paper in this area, skip to the fuser area
around the toner cartridge.
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Samsung Electronics
6.2.3 JAM1 (In the Fuser Area or Around the Toner Cartridge Area)
NOTE : The fuser area is hot. Be careful when removing paper from the machine.
1) Open the front cover and remove the toner cartridge. 3) Replace the toner cartridge and close the front cover.
Printing automatically resumes.
2) Remove the jammed paper by gently pulling it

straight out.
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6.2.4 JAM 2 (In the Paper Exit Area)

1) Open and close the front cover. The jammed paper 4) Remove the jammed paper by gently pulling it
automatically exits the machine. straight out..
If the paper does not exit, continue to Step 2.
2) Gently pull the paper out of the front output tray.
5) Close the rear cover.
3) If there is any resistance when you pull the paper or 6) Open and close the front cover to resume printing.
the paper is not seen in the front output tray, open
the rear cover.
co m
o u .
ls 4y
Service Manual nua
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Samsung Electronics
6.2.5 MP-Tray Jam (In the Bypass Tray)

“MP Tray Jam” appears on the display when you try to print using the manual feeder and the machine does not
detect paper, due to no paper or improper paper loading.
The error message may also occur when the paper is not properly fed into the machine through the manual feeder.
In that case, pull the paper out of the machine.
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6.3 User Mode(SCX-4520)
The table below shows the map of User settings available in User Mode. These are fully described in the
User Guide and are not included here.
1.Paper Setting 2.Copy Setup 6.Reports

Paper Tray Change Default System Data
Paper Size Timeout
9.Maintenance 8.Machine Setup

Clean Drum Language
Clear Memory Power Save
CCD Power Save
USB Mode
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Samsung Electronics
6.3 User Mode(SCX-4720F)
The table below shows the map of User settings available in User Mode. These are fully described in the
User Guide and are not included here.
1.Paper Setting 2.Copy Setup 3.Fax Setup

Paper Tray Change Default Receive Mode
Paper Size Timeout Ring to Answer
Contrast
Redial Term
Redials
MSG Confirm.
Auto Report
Auto Reduction
Discard Size
4.Fax Feature 5.Advanced Fax 6.Reports

Delay Fax Send Forward Phone Book
Priority Fax RCV Forward Send Report
Add / Cancel Toll Save RCV Report
Junk Fax Setup System Data
Secure Receive Scheduled Jobs
Prefix Dial No Tx Confirm.
Stamp RCV Name Junk Fax List
ECM Mode
7.Sound/Volume 8.Machine Setup 9.Maintenance

Speaker Machine ID Clean Drum
Ringer Date&Time Notify toner
Key Sound Clock Mode Clear Memory
Alarm sound Dial Mode
Language
Power Save
CCD Power Save
USB Mode
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6.4 Tech Mode
6.4.1 How to Enter Tech Mode

In service (tech) mode the technician can check the machine and perform various tests to help with failure
diagnosis.
When in Tech mode the machine still performs all normal operations.
While in Tech mode the machine still performs all normal operations.
To enter the Tech mode

To enter the Tech mode press in sequence and the LCD
briefly displays ‘TECH’, the machine has entered service (tech) mode.
6.4.2 Setting-up System in Tech Mode
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6.4.3 Data Setup

SEND LEVEL
You can set the level of the transmission signal. Typically, the Tx level should be under -12 dBm.
Caution : The Send Fax Level is set to the best condition during manufacture. Never change settings arbitrarily.
DIAL MODE
This function can choose the dialing method.
*Default : Dial (Dial/Pulse)
MODEM SPEED
You can set the maximum modem speed.
When the fax establishes communication with a remote set the value of the maximum modem speed is
checked for both transmitter and receiver. The lowest value is used. It is best set at 33.6Kbps, the default
setting.
ERROR RATE
When the error rate is about exceed the set value, the Baud rate automatically adjusts to 2400 bps.
This ensures that the error rate remains below the set value.
You can select the rate between 5% and 10%.
CLEAR ALL MEMORY

The function resets the system to factory default settings.
This function is used to reset the system to the initial value when the product is functioning abnormally.
All the values are returned to the default values, and all the information which was set by the user
will be erased.
< Method >

1. Select the [MEMORY CLEAR] in TECH MODE.
2. Push the ENTER button.
3. Select your country. (There are four country groups. Refer to the table below.)
4. Push the ENTER button then it will clear all memory.
NOTICE : Always perform a memory clear after replacing the main board, otherwise the system may
not operate properly.
Country Group USA/Canada UK Russia Southafrica
USA/Canada UK Russia South Africa
Mexico Germany India
Brazil France Oman
Italy Poland
Spain Bangladesh
Kuwait
Netherlands Moroco
Belgium Algeria
Country Portugal Pakistan
Sweden UAE
Norway Bahrain
Denmark Srilanka
Finland Saudi Arabia
Switzerland Chile
Greece Peru
Ireland Argentina
Turkey Hungary
Romania
Bulgaria
Czech
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FLASH UPGRADE
There are 2 methods to update the Flash Rom, Local and Remote.
(1) Local Machine
• RCP (Remote Control Panel) mode

This method is for Parallel Port or USB Port. Connect the PC and activate the RCP (Remote Control Panel) to
upgrade the Firmware.
< Method >

How to Update Firmware using RCP
1. Connect PC and Printer with a Parallel Cable or a USB Cable.
2. Run the RCP utility and select Firmware Update.
3. Search for the Firmware file to be used to update the set using the Browse Icon.
4. Click the Update icon. The firmware file is transmitted to the Printer automatically and the printer is
initialized when the download completes.
5. Click the Refresh icon and check that the updated version numbers are displayed.
• DOS Command mode

This method is ONLY for Parallel Port. Connect the PC to the set using a Parallel Cable and enter the DOS
Command to upgrade the firmware.
< Method >

1. First of all you need the following files : down.bat, down_com.bin, fprt.exe, and Rom File: (file name for
upgrade). Ensure you save ALL of these files in the same folder.
2. At the DOS prompt enter the correct command (as shown below) and push the enter key.
Then the upgrade will automatically take place..
3. There are two commands use the correct one depending on the condition of the set..
* When the product is in the idle condition
down "rom file"
* When the product is in Ready condition
(TECH MODE --> DATA SETUP --> FLASH UPGRADE --> LOCAL)
fprt "rom file"
4. Do not turn off the power during the upgrade process.
(2) Remote FAX
It is possible to use a set that already has the latest firmware to upgrade a remote set remotely using the tele-
phone system.
< Method >

1. On the set that has the latest firmware set it toi transmit the upgrade:-
(TECH MODE •DATA SETUP•••• FLASH UPGRADE•••• REMOTE)
2. Enter the telephone number of the set that needs to be upgraded.
(Several faxes can be upgrade at the same time. In this case, enter each fax number.)
3. When the enter button is pressed the set sends the firmware file by calling designated fax number.
(Around 10~15 minutes are needed to send the file.)
< Caution >

1. The Sending and Receiving fax machines MUST be the same model.
2. The sending fax must be set up in ECM mode and the Receiving fax memory must be 100%.
If not the function will not work.
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6.4.4 Machine Test

SWITCH TEST
Use this feature to test all keys on the operation control panel. The result is displayed on the LCD window each
time you press a key.
MODEM TEST
Use this feature to hear various transmission signals to the telephone line from the modem and to
check the modem, amplifier and speaker. If no transmission signal sound is heard, it means the
modem part of the main board, amplifier, speaker or speaker harness is faulty.
DRAM TEST
Use this feature to test the machine's DRAM. The result appears in the LCD display.
If all memory is working normally, the LCD shows << O K >>
ROM TEST
Use this feature to test the machine's ROM. The result and the software version appear in the LCD
display.
• FLASH VER : 1.00 V
• ENGINE VER :1.00V
PATTERN TEST
Using this pattern printout you can check that the printer mechanism is functioning properly.
This function is for factory manufacturing use only.
SHADING TEST
The function is used to set the optimum scan quality determined by the specific characteristics of
the CCD (Charge Coupled Device). If copy image quality is poor perform this function to check the
condition of the CCD unit.
< Method >

1. Select the [Shading Test] in TECH MODE
(Menu, #, 1934).
2. Push the ENTER button and an image will
be scanned.
3. After scanning the CCD SHADING PRO-
FILE will be print out.
4. If the printed image is different to the sample
image shown the CCD is defective.
NOTICE : When you test the CCD, make

sure that the cover is closed.
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6.4.5 Report
PROTOCOL LIST
This list shows the sequence of the CCITT group 3 T.30 protocol during the most recent sending or receiving
operation. Use this list to check for send and receive errors. If
SYSTEM DATA
This list provides a list of the user system data settings and tech mode settings.
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6.5 Engine Test Mode

The Engine Test Mode supplies useful functions to check the condition of the print engine. It tests the con-
dition of each device and displays the result of the test on the LCD. It is divided into 5 functions (0~4), and
these are shown below.
6.5.1 To enter the Engine Test Mode

To enter the Engine Test mode
Press in sequence, and the LCD briefly displays

‘Engine Test’, the machine has entered Engine Test Mode.
Press “0”, “1”, “2”, “3” or “4” to select the Test No. (see list below – left hand column)
6.5.2 Diagnostic
NO. Sub No. Engine test Remark
0 1 Motor Test 1 : On, 2 : Off – next test selected
2 Pick Up Test 1 : On, 2 : Off – next test selected
3 Fan Test 1 : On, 2 : Off – next test selected
4 Manual Clt Test 1 : On, 2 : Off – next test selected
5 PTL Test 1 : On, 2 : Off – next test selected
1 1 LSU Motor Test 1 : On, 2 : Off – next test selected
2 LSU Hsync Test 1 : On, 2 : Off – next test selected
3 LD Test 1 : On, 2 : Off – next test selected
2 1 Feed Sensor Test 1. Check : read the sensor
2. Next : Next Sensor test
2 Exit Sensor Test 1. Check : read the sensor
3 Cover Sensor Test 1. Check : read the sensor
4 Empty Sensor Test 1. Check : read the sensor
5 Manual Sensor Text 1. Check : read the sensor
3 1 Therm ADC 180 1 : On, 2 : Off (maintain the fusing temp. 80˚C)
2 Therm ADC 140 1 : On, 2 : Off (maintain the fusing temp. 135˚C)
4 1 MHV Test 1 : On, 2 : Off (-1550V ± 50V)
2 Dev Bias Test 1 : On, 2 : Off (-430V ± 20V)
3 THV EN/NEG Test 1 : On, 2 : Off (-1200V +300V/-150V)
4 THV ON (1300V) 1 : On, 2 : Off (+1300V ± 20V)
5 THV ADC 1300V 1 : On, 2 : Off (ADC Value : 101 ± 5)
6 THV ADC 600V~3500V 1 : On, 2 : Off (Compare each ADC Value)
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6.5.3 Detail Description (Engine Test Mode)
Function Name Description Display

01.Motor Test The main motor starts when the execution key is pressed Main Motor On/Off
and stops when the stop key is pressed.
02.Pick Up Test Automatically stops, when the execution is chosen. Tray 1,2 Solenoid On/Off
stops, when the execution is chosen.
03.Fan Test The fan starts when the execution key is pressed and Fan On/Off
stops when the stop key is pressed.
04.Manual Clutch Test The tray2,3 clutch is on for 1sec and then it automatically Tray 2,3 Clutch On/Off
stops, when the execution is chosen.On this function,
the main motor runs before 2sec from the point of the clutch
on in order to check the clutch state.
05.PTL Test PTL(Pre-Transfer Lamp) is lights when the execution key PTL On/Off
chosen and it stops when the stop key is chosen.
11.LSU Motor The laser motor starts when the execution key is pressed Laser Motor On/Off
and stops when the stop key is pressed.
12.LSU Hsync Test The LSU motor starts and "Laser Ready" is displayed if Laser Leady On/Off
the motor spins at the correct speed, otherwise "Laser Error"
is displayed.
13.LD Test "Diode On" is displayed, when the laser diode is on. Diode On/Off
Otherwise "Diode Off" is displayed.
21.Feed Sen Test These functions allow the current state of the sensor to be "Sensor Off" or “ Sensor On ”
22.Exit Sen Test displayed.
23.Cover Sen Test This function allows the current state of the Cover sensor "Cover Open" or "Cover Close"
to be displayed. Touch the sensor and confirm that the
message changes: "Cover Open" to " Cover Close"
24.Empty Sen Test These functions allow the current state of the sensor to be "Sensor Off" or “ Sensor On ”
25.Manual Sen Test displayed.
31.Them ADC 180 "Current value" is displayed on the upper line of the LCD, Target temperature and
32.Them ADC 140 and "Target value" on the bottom line. output temperature from
33.Them ADC 120 Target value is limited from "191°C" to "80°C" thermistor and ADC.
34.Them ADC 100
41.MHV Test These Functions are provided to check whether the MHV On/Off
42.Dev Bias Test control of the HVPS is functioning correctly. Dev Bias On/Off
43.THV EN/NEG Test THV EN/NEG On/Off
44.THV ON(1300V) THV On/Off
45.THV ADC 1300V ADC value displayed.
46.THV ADC 600V~3500 ADC value displayed.
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6.6 Identify Sale Date

This function confirms the date that the consumer bought the product and used the product for the first time.
When the consumer first operates the machine, it will start the scan and page counters.
The time the machine was first used is also displayed.
These settings are remembered after memory delete (Clear All Memory).
< Method >

Press MENU, #, 1, 9, 3, # in sequence. The Firmware version is displayed on the LCD.
Press 1( in the number keypad) : The LCD display shows "Updated date"
Press 2( in the number keypad) : The LCD display shows "Product first use date"
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6.7 Consumables and Replacement Parts

The life cycle outlined below is a general guideline for maintenance purposes and is for reference only.
Environmental conditions (temperature, humidity, dust etc.) and actual use can cause these figures to vary.
COMPONENT REPLACEMENT CYCLE

ADF Rubber 20,000 Pages
Pick-up Roller 150,000 Pages
Friction Pad 60,000 Pages
Transfer Roller 60,000 Pages
Fuser Unit 80,000 Pages
Toner Cartridge 3,000 Pages (A4 ISO 5% Pattern)
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6.8 Abnormal Image Printing and Defective Roller
If a mark or other printing defect occurs at regular intervals down the page it may be caused by a damaged or
contaminated roller. Measure the repetition interval and refer to the table below to identify the roller concerned.
L S U
Fuser CR
Toner Cartridge
DR
OPC SR
PR
PTL MP Sensor
TR FR
K/
R
P IC
1 OPC Drum 5 Transfer Roller

2 Charge Roller 6 Heat Roller
3 Supply Roller 7 Pressure Roller
4 Developing Roller
No Roller Abnormal image period Kind of abnormal image

1 OPC Drum 75.5mm White spot, Block spot
2 Charge Roller 37.7mm Black spot
3 Supply Roller 44.9mm Horizontal density band
4 Develop Roller 35.2mm Horizontal density band
5 Transfer Roller 47.1mm Black side contamination/transfer fault
6 Heat Roller 77.8mm Black spot and fuser ghost
7 Pressure Roller 75.4mm Black side contamination
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6.9 Error Messages

The front panel displays the printer's status or error messages. Refer to the list below for an explanation of these
messages and how to clear problems. The messages and their meanings are listed in alphabetical order, with numbered
messages following.
MP Tray Jam [Door Open]

Meaning: A paper jam has occurred in the manual feeder or the multi-function printer detects improper feeding from
the manual feeder.
Solution: Clear the paper jam. Load paper in the manual feeder correctly.
Cancel ? 1. Yes 2. No (Only SCX-4720F)

Meaning: While storing the document in memory the memory has become full.
Solution: To cancel the fax job, press the ‘1’ button to accept “Yes.” If you want to send the pages that were stored
press the ‘2’ button to accept “No.” This will send ONLY the pages stored. The remaining pages should be
sent later when more memory becomes available.
[COMM. Error] (Only SCX-4720F)

Meaning: The multi-function printer has a communication problem.
Solution: Ask the sender to try again.
Low Heat Error / Open Heat Error

Meaning: There is a problem in the fuser unit.
Solution: Check thermostat, thermister contact point & Heating Lamp.
[Over Heat]
Meaning: The printer has overheated.
Solution: Your unit will automatically return to the standby mode when it cools down to normal operating temperature.
If failure persists,check the ELA HOU-FUSER.
Delayed Function Full (Only SCX-4720F)

Meaning: The delayed fax job list or memory space is full.
Solution: Cancel any unnecessary delayed fax jobs.
Document Jam
Meaning: The loaded document has jammed in the Automatic Document Feeder (ADF).
Solution: Clear the document jam.
[Door Open]
Meaning: The front or rear cover is not securely latched.
Solution: Close the cover until it locks into place.
Enter Again
Meaning: You entered an unavailable item.
Solution: Enter the correct item again.
Function Impossible
Meaning: You have tried to use a combination of printer functions that can not be used at the same time.
Solution: Reduce the number of selected functions or use only one function at a time.
Group Not Available (Only SCX-4720F)

Meaning: You have tried to select a group location number where only a single location number can be used, such
as when adding locations for a broadcasting operation.
Solution: Use a speed dial number or dial the number manually using the number keypad.
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[LSU Error]
Meaning: A problem has occurred in the Laser Scanning Unit (LSU).
Solution: Use TECH mode to test LSU. Replace the LSU
Invalid Cartridge or No Cartridge

Meaning: You have used an unauthorized cartridge.
Solution: You must use a Samsung approved cartridge.
[Line Error] (Only SCX-4720F)

Meaning: Your machine cannot connect with the remote machine or has lost contact because of a problem with the
phone line.
Solution: Try again. If the problem persists, wait an hour or so for the line to clear and try again. Or, turn the ECM
on.
Memory Full (Only SCX-4720F)

Meaning: The memory is full.
Solution: Delete any unnecessary documents (delayed transmission, broadcast or polling jobs) or retransmit after
more memory becomes available. This can also be caused when a large complex document with many
pages is being sent, try splitting the job into more than one operation.
[No Answer] (Only SCX-4720F)

Meaning: The remote fax machine has not answered after several redial attempts.
Solution: Try again. Verify the number to make sure a fax can be received.
No. Not Assigned (Only SCX-4720F)

Meaning: YThe speed dial location you tried to use has no number assigned to it.
Solution: Dial the number manually using the number keypad or assign the number.
No. Not Available (Only SCX-4720F)

Meaning: You have tried to delete the number for a delayed fax job.
Solution: Verify the number to be deleted and try again.
Or Delete the number after the delayed fax job is completed or deleted.
[No Paper] Add Paper

Meaning: The paper in the paper tray has run out.
Solution: Load paper in the paper tray.
Operation Not Assigned (Only SCX-4720F)

Meaning: You are performing an Add / Cancel operation, but there are no jobs waiting.
Solution: Check the display to see if there are any scheduled jobs. The display should indicate if any scheduled jobs
are in Standby mode, for example, Delay Fax.
[Paper Jam 0] Open/Close Door

Meaning: Paper has jammed in the feeding area of the paper tray.
Solution: Clear the jam.
[Paper Jam 2] Check Inside

Meaning: Paper has jammed in the paper exit area.
Solution: Clear the jam.
[Power Failure]
Meaning: The power has been turned off and then on and the printer’s memory has not been saved.
Solution: The printer’s memory was not saved due to a power failure. The job will need to be started over.
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Registered
Meaning: The group dial location is already registered with another speed dial number.
Solution: Select another group dial location.
[Retry Redial?] (Only SCX-4720F)

Meaning: The multi-function printer is waiting for a specified time interval to redial a previously busy station.
Solution: You can press <Select>to immediately redial, or <Cancel>to cancel the redial operation.
[Toner Low]
Meaning: The toner is almost empty.
Solution: Take out the toner cartridge and gently shake it. By doing this, you can temporarily reestablish printing
operations.
Or Replace the toner cartridge with a new one for the best print quality.
Priority Fax Function Full (Only SCX-4720F)

Meaning: The priority fax job queue is full.
Solution: Cancel any unnecessary priority fax jobs.
[Incompatible] (Only SCX-4720F)

Meaning: The remote machine did not have the requested feature, such as a sending a color fax.
This message also occurs if the remote machine does not have enough memory space to complete the
operation you are attempting.
Solution: Reconfirm the remote machine’s features.
[Jam 1] or [No Cartridge]

Meaning: Paper has jammed in the paper exit area. Or, the toner cartridge is not installed.
Solution: Clear the jam. Or, install the toner cartridge.
[Line Busy] (Only SCX-4720F)

Meaning: The receiving party did not answer or the line is already engaged.
Solution: Try again after a few minutes.
Load Document
Meaning: You have attempted to set up a copy or fax operation with no document loaded into the ADF.
Solution: Load a document into the ADF and try again.
Scanner Locked
Meaning: The scanner module is locked
Solution: Unlock the scanner and press Stop/Clear.
[Stop Pressed]
Meaning: The Stop/Clear button has been pressed during a copy or fax operation.
Solution: Try again.
[Toner Empty] Replace Toner

Meaning: The toner cartridge has run out. The machine stops printing.
Solution: Replace the toner cartridge with a new one.
[Retry Redial?] (Only SCX-4720F)

Meaning: The machine is waiting for a specified time interval to redial a previously busy station.
Solution: You can press Enter to immediately redial, or Stop/Clear to cancel the redial operation.
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Troubleshooting
7
7. Troubleshooting
7.1 Paper Feed problems – Causes and Solutions
7.1.1
• Description
Wrong Print Position
Printing begins when the paper is in the wrong position.
Check and Cause Solution

A defective feed sensor actuator can cause incorrect Replace the defective actuator
timing.
7.1.2 JAM 0
1. Paper does not exit from the cassette.

• Description
2. Jam-0 occurs when the paper feeds into the printer.

L S U
1. Check the Solenoid by using Tech 1. Replace the solenoid.
Fuser CR
DR
Toner Cartridge
Mode.
EXIT OPC SR
Sensor PR
PTL Feed MP Sensor
TR Sensor FR
2. Check cassette/MP knock-up plate 2. Repair / replace as required

K /R
P IC
Empty Sensor
and springs.
3. Check paper separator pad 3 Clean with soft cloth dampened with
IPA (Isopropyl Alcohol) or water.
Replace if required.
4. Check the pick up roller for 4. Clean with soft cloth dampened with
contamination and correct assembly. IPA (Isopropyl Alcohol) or water.
Replace if required
5. If continuous clusters occur, check all 5. Ensure all rollers are clean and free to
rollers between pickup and registration operate correctly.
sensor.
6 If the paper feeds into the printer and 6. Check the SMPS PBA, Main PBA and
Jam 0 occurs, perform Tech Mode to all connections. Replace any faulty
check feed sensor. parts or the
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Troubleshooting
7.1.3 JAM 1
1. Recording paper is jammed in front of or inside the fuser.

• Description 2. Recording paper is stuck in the discharge roller and in the fuser just after passing through the
Actuator-Feed.

L S U
Fuser CR
Toner Cartridge
1. If the recording paper is jammed in 1. Replace the SMPS.
EXIT
Sensor PR
OPC
DR
PTL
SR
Feed MP Sensor
front of or inside the fuser.
TR Sensor FR
K /R
P IC
Empty Sensor
2. If the recording paper is stuck in the 2. Reassemble the Actuator-Feed and
discharge roller and the fuser just Spring-Actuator if the return is bad.
after passing through the Actuator-
Feed, Feed Actuator may be defec
tive.
7.1.4 JAM 2
1. Recording paper is jammed in front of or inside the fuser.

• Description 2. Recording paper is stuck in the discharge roller and in the fuser just after passing through the
Actuator-Feed.

L S U
1. If the paper is completely fed out of 1. Check if the exit sensor actuator is
Fuser Toner Cartridge
the printer, but Jam 2 occurs: The defective.
CR
DR
EXIT OPC SR
Sensor PR
TR
PTL Feed
Sensor FR
MP Sensor
Exit sensor may be defective. • Check if the actuator exit is deformed

• After the paper is completely (Check if the lever part is deformed).
K /R
P IC
Empty Sensor
discharged the Exit sensor actuator • Check whether burrs occur in the
should return to its original position assembly part of the exit actuator
to shut the photo-sensor. It may and if the actuator operates smoothly.
stick open or return only slowly due • Check if foreign objects or paper
to contamination be paper debris or debris are preventing the correct
foreign objects. operation of the actuator.
2. If the paper is rolled in the Fuser 2. If the paper is stuck in the fuser :
Roller: disassemble the fuser and remove the
• This occurs when a Guide claw is jammed paper, and clean the surface
broken away, damaged or of the pressure roller with dry gauze.
deformed. Check all ribs, claws and springs.
• It occurs when the Spring of a
Guide claw is broken or damaged.
• It occurs when the Heat-Roller or
Pressure-Roller is seriously
contaminated with toner.
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Troubleshooting
7.1.5 Multi-Feeding
• Description Multiple sheets of paper are fed at once.

1. Check that the paper size guides are set correctly 1. Adjust paper guides.
(cassette and MPF tray).
2. Solenoid malfunction (the solenoid does not work 2. Replace the solenoids or PBA as appropriate.
properly).
3. Friction Pad is contaminated. 3. Clean the friction pad rubber with a soft cloth
dampened with IPA (Isopropyl Alcohol) or water.
4. Paper has a rough surface texture. 4. Use paper with a smother surface finish.
7.1.6 Paper rolled in the fuser
• Description Paper rolled around fuser rollers or ‘Concertina’ jam

1. Contamination of the pressure roller or heat roller. 1. After disassembling the fuser, clean contamination
from between the heat roller and the thermistor and
also clean contamination from the pressure roller.
Clean the surface of the rollers with IPA or water
2. Damaged or deformed ribs, claws or springs. 2. Check for damage or deformation of the print claws
and the holder plate claws, and repair or replace as
appropriate.
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Troubleshooting
7.1.7 Paper rolled on the OPC Drum
• Description Paper is rolled up in the OPC.

1. Paper is too thin. 1. Use paper that conforms to the printer specification.
2. The face of paper is curled. 2. Ensure paper is stored properly to prevent curl.
Note. To remove paper rolled in the OPC.

• Remove the toner cartridge from the set, taking
care not to touch the green surface. Use the
gearwheel at the side to rotate the OPC drum and
pull the paper from the cassette.
• Clean fingerprints on the OPC gently with soft
tissue, taking care not to scratch the surface.
7.1.8 Defective ADF
• Description ADF (Automatic document Feeder) does not operate correctly.

1. Check if the ADF rubber or HOLDER rubber are 1. Replace the contaminated or damaged part.
damaged or contaminated.
2. Check if the ADF Ass'y document sensors (3 paper 2. If you cannot confirm the damaged part with the
sensors) are working correctly.
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Troubleshooting
7.2 Set Malfunction – Causes and Solutions
7.2.1 LCD Display Defect ( in LCD Display)
• Description Strange characters are displayed in the LCD Window and OPE Panel buttons do not work.

1. Clear the memory. (see page 6-18) 1. Try again after clearing the memory.
2. Check that the OPE HARNESS is connected to 2. If re-connecting the harness does not correct
the Connection Board correctly. the fault replace the OPE Ass’y and the main
Board in sequence.
7.2.2 Defective OPE Keypad
• Description Pressing keys does not cause the set to respond correctly

1. Clear the memory. (See page 6-18). 1. Check that the keypad is assembled correctly and
the membrane is not damaged, replace the
membrane or whole keypad assembly if necessary.
2. Check that there is an audible key click when a key is 2. If the fault remains replace the OPE Ass’y and the
pressed. Main board in sequence.
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Troubleshooting
7.2.3 Fuser gear melts due to overheating causing Paper Jam.
• Description Constant Jam where paper is entering Fuser unit.

Fuser rollers do not turn

1. Check the Heat Lamp, thermostat and thermistor 1. Use EDC Mode to test the fuser.
Replace Fuser unit

Replace SMPS or Main PBA as appropriate.
7.2.4 Paper Empty
• Description Paper Empty is displayed in the LCD panel even when paper is loaded in the cassette.

1. Deformed paper sensor actuator or faulty sensor. 1. Replace the defective actuator or sensor.
2. SMPS PBA or Main PBA is defective 2. Replace the SMPS PBA or MAIN PBA as
appropriate.
3. Faulty cables or connectors.
7.2.5 Paper Empty without indication
• Description The paper empty message does not appear in the LCD when the paper cassette is empty.

1. Deformed paper sensor actuator or faulty sensor. 1. Replace the defective actuator.
2. SMPS PBA or Main PBA is defective 2. Replace the SMPS PBA or MAIN PBA as
. appropriate
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Troubleshooting
7.2.6 Cover Open
• Description The Cover Open message appears on the LCD even when the print cover is closed.

1. The ‘Open Cover’ microswitch may be stuck or faulty 1. Use TECH mode(“cover sensor test”) to check
cover switch operation. Check and replace switch if
necessary.
2. The tab on the front cover may be damaged or broken 2. Replace the front cover.
3. Check the connector and cables between Switch and 3. Replace the Main Control board or Cover Open
main PBA. S/W as necessary.
7.2.7 No error message when the cover is open
• Description The Cover Open message does not appears on the LCD even when the print cover is open.

1. The ‘Open Cover’ microswitch may be stuck or faulty 1. Use TECH mode(“cover sensor test”) to check
cover switch operation. Check and replace switch if
necessary.
2. Check the connector and cables between Switch and
main PBA. 2. Replace the Main Control board or Cover Open
S/W as necessary.
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Troubleshooting
7.2.8 Defective motor operation
• Description Main motor is faulty and paper does not feed into the printer, resulting in Jam 0'

1. The main motor harness or Motor PCB may be faulty. 1. Check the motor harnesses and connectors, replace
if defective.. If the problem persists replace the main
PBA.
Note Check motor operation using EDC Mode.
7.2.9 No Power
• Description When system power is turned on the LCD panel does not come on.

1. Check if the power input and SMPS output are normal. 1. Replace the power supply cord or SMPS. Check
power fuse and SMPS fuses replace if necessary.
2. LCD panel does not come on but normal start up 2. Replace the OP panel.
sounds are heard.
3. After replacing SMPS display does not come on and no 3. Replace the main PBA panel.
start up sounds are heard.
7.2.10 Printed Vertical Lines become curved
• Description When printing, vertical lines are not straight.

1. Check stability of 24V supply to LSU. 1. 24V stable - Replace LSU.
24V unstable replace SMPS, if the problem persists
replace the main PBA.
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Troubleshooting
7.3 Paper Feed Problems – Causes and Solutions
7.3.1 Wrong Print Position
• Description Printing begins when the paper is in the wrong position.

Digital Printer A defective feed sensor actuator can cause Replace the defective actuator
Digital Printer incorrect timing.
Digital Printer
Digital Printer
Digital Printer
7.3.2 Vertical White Line
• Description White vertical voids in the image.

Digital Printer 1. 1. Contamination of the window or 1. Clean the LSU window with recommended
Digital Printer internal lenses of LSU mirror. cleaner (IPA) Clean the window with a
Digital Printer clean cotton swab. If dirt is inside the LSU
Digital Printer – replace LSU.
Digital Printer 2. Foreign object inside the toner cartridge 2. Replace the toner cartridge.
or low toner.
3. Foreign object, contamination or burr on 3. Clean the exposure window.

the edge of the toner cartridge window.
4. If the fuser is defective, voids occur 4. Open the front cover and check the ribs
periodically at the top of a black image. that correspond to the position of the
voids. Remove if found.
5. Contamination of the OPC drum. 5. If the problems are not solved, replace
the toner cartridge.
6. Depression or deformation of the surface 6. Replace the transfer roller.

of the transfer roller
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Troubleshooting
7.3.3 Horizontal Black Bands
1. Dark or blurry horizontal stripes occur in the printing periodically.

• Description
(These may occur at regular intervals down the page.)

Digital Printer 1. Bad contacts on the toner cartridge high 1. Clean all HV terminals on the cartridge and
Digital Printer voltage terminals. on the set frame. Ensure all toner or paper
Digital Printer dust particles are removed.
Digital Printer
2. The rollers in the toner cartridge may be 2. Clean the right Gear that has relatively
Digital Printer contaminated. small tooth gap on the OPC.
Charge roller = 37.7 mm
Supply roller = 44.9 mm
Develop roller = 35.2 mm
Transfer roller = 47.1 mm
3. If the problem persists replace the toner

cartridge.
7.3.4 Black/White Spot
1. Dark or blurry black spots occur periodically in the printing.

• Description
2. White spots occur periodically in the printing.

Digital Printer
1. If dark or blurry black spots occur periodi- 1. Print several OPC cleaning Mode Prints
Digital Printer cally, the rollers in the Developer may be and then run the Self-test 2 or 3 times.
Digital Printer contaminated with foreign matte or paper
Digital Printer particles.
( Charge roller : 37.7 mm interval
Digital Printer
OPC drum : 75.5 mm interval)
2. If faded areas or voids occur in a black 2. 75.5 mm repetition: Examine the surface of
image at intervals of 75.5 mm, or black the OPC drum and carefully clean with a
spots occur elsewhere, the OPC drum soft, lint free cloth. If unsuccessful replace
surface is damaged. the cartridge.
37.7mm repetition: Replace the toner car-

tridge
3. If a black image is partially broken, the 3. The transfer roller guarantees 60,000
transfer voltage is abnormal or the sheets printing. If the roller's life is expired,
transfer roller's life has expired. replace it.
Note. Cleaning the inside of the set to

remove excess toner particles or paper
dust will reduce the occurrence of this
problem..
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Troubleshooting
7.3.5 Light Image
• Description The printed image is light, with no ghost.

Digital Printer
1. Toner Save mode enabled 1. Ensure the Toner Save mode is off. Check
Digital Printer set and driver settings.
Digital Printer
Digital Printer 2. Develop roller is contaminated or the 2. Replace the toner cartridge and try to print
toner cartridge is almost empty. out again.
Digital Printer
3. Ambient temperature is below than 10°C. 3. Wait 30 minutes after printer is powered on
before you start printing.
4. Bad contact caused by dirty terminals on 4. Clean the cartridge and set contacts.
the toner cartridge or set. Generally clean dirt from inside the set.
5. Abnormal output from the HVPS. 5. Replace the HVPS if the problems are not
(Run EDC mode – see sections 6.5.1 solved by the above four instructions.
and 6.5.3)
7.3.6 Dark Image or a Black
• Description The printed image is dark.

Digital Printer
1. No charge voltage in the engine board. 1. Check the state of the connector which
Digital Printer connects the engine board and HVPS.
Digital Printer
Digital Printer 2. Charge voltage fault due to bad contact 2. Clean the high voltage charge terminals.
between toner cartridge and set contacts. Note if 1 and 2 do not resolve the problem
Digital Printer and the problem persists replace the
HVPS.
3. VD0 signal of the Main PBA is Low state. 3. Replace the LSU Unit or Main PBA.
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Troubleshooting
7.3.7 Uneven Density
• Description Print density is uneven between left and right.

1. The pressure force on the left and right 1. Replace both the left and right bush and
springs of the transfer roller is not even, spring assemblies.
the springs are damaged, the transfer
roller is improperly installed, or the trans-
fer roller bushing or holders are damaged.
2. The life of the Toner cartridge has 2. Replace the toner cartridge and try to print out
expired.
3. The toner level is not even on the toner 3. Gently shake the toner cartridge and try
cartridge roller due to the damaged blade printing again. If the problem persists
or low toner. replace the toner cartridge.
7.3.8 Background
• Description Light dark background appears in whole area of the printing.

Digital Printer
1. Printing large quantities of low coverage 1. The toner cartridge is basically designed to
Digital Printer (2%) pages or the printer has not been print 3,000 sheets with 5% image. If it
Digital Printer used for a long time. prints more than 3,600 sheets with 2%
Digital Printer coverage, a background can occur.
Digital Printer 2. Is a recycled toner cartridge be 2. The A/S is not guaranteed if using a recy-
used? cled toner cartridge.
Note try shaking the toner cartridge gently

from side to side. If the problem persists
replace the toner cartridge.
3. Has the life span of the toner 3. Replace the toner cartridge when its life is
manuals4you.com
cartridge ended? expired.
4. Is the movement(Up and Down) of 4. Clean the transfer roller bushes.

the transfer roller smooth?
5. Is the HVPS normal? 5. Clean the high voltage charge terminals.

If this does not resolve the problem replace
the HVPS.
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Troubleshooting
7.3.9 Ghost (1)
• Description Ghost occurs at 75.5 mm intervals of the OPC drum in the whole printing.

Digital Printer 1. Bad contacts caused by contamination 1 and 2. Clean all HV contacts, If problem
Digital Printer from toner particles between high voltage persists replace the HVPS.
75.5 mm
Digital Printer terminal in the main body and the elec-

Digital Printer trode of the Toner cartridge. If problem still persists replace the Main PBA
Digital Printer
Digital Printer 2. Bad contacts caused by contamination
from toner particles between high voltage
terminal in the main body and the one in
the HVPS board.
3. Replace the toner cartridge and try to print
3. The life of toner cartridge is expired. out.
4. Check the transfer roller lifetime and

4. Transfer roller life (60,000 sheets) has replace it.
expired.
5. Wait about 30 minutes after power on
5. Low ambient temperature (below 10°C). before using printer.
6. Replace the toner cartridge and try to print

6. Damaged cleaning blade in the toner out again
cartridge.
7.3.10 Ghost (2)
Ghost occurs at 75 mm intervals of the OPC drum in the whole printing.

• Description
(When printing on card stock or transparencies using manual feeder)

Digital Printer When printing on card stock, thicker than Ensure that the correct paper type is selected
Digital Printer normal paper or transparencies, such as in the printer driver or application software.
75 mm
Digital Printer OHP, a higher transfer voltage is required. Remember to set back to normal paper after
Digital Printer use.
Digital Printer
Digital Printer
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Troubleshooting
7.3.11 Ghost (3)
• Description Ghost occurs at 66.3 or 75.5 mm intervals.

Digital
Digital Printer
Printer Fuser contamination. 1. Disassemble the fuser and remove any
32 mm
contamination on the rollers. Clean any

Digital
Digital Printer
Printer contamination from between the
Thermistor and the Heat roller. (Caution:
Digital
Digital Printer
Printer Take care not to deform the rollers.)
7.3.12 Ghost (4)
• Description A White ghost occurs in a black image printing at 32 mm intervals.

Digital
Digital Printer
Printer 1. The life of the developer may be expired. 1. Problem in the toner cartridge, replace the
32 mm
toner cartridge and try to print out again.

Digital
Digital Printer
Printer
2. Abnormal output from the HVPS. 2. Check the HVPS supply voltage. Clean all
Digital
Digital Printer
Printer (Run EDC mode – see sections 6.5.1 HV terminals on the cartridge and on the
and 6.5.3) set. Replace the HVPS if the problem
persists.
7.3.13 Stains on the Face of the Page
• Description The background on the face of the printed page is stained.

Digital Printer
1. Toner leakage due to improperly sealed 1. Replace the toner cartridge.
Digital Printer toner cartridge.
Digital Printer
Digital Printer 2. If the transfer roller is contaminated, 2. If the transfer roller is contaminated, run
stains on the face of page will occur. PC Cleaning Mode Print 2 or 3 times and
Digital Printer then perform Self-Test 2 or 3 times to
remove contamination.
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Troubleshooting
7.3.14 Stains on Back of Page
• Description The back of the page is stained at 47.1 or 75.4 mm intervals.

Digital
1. 47.1mm : Transfer roller is contaminated. 1. Perform the OPC Cleaning Mode Print 2 or
Digital Pri 3 times. Run Self-Test to remove the
Digital Printer contamination from the transfer roller.
Digital Printer
Note. Replace the transfer roller if
Digital Printer
contaminated severely.
2. 75.4mm : Pressure roller is contaminated. 2. Disassemble the fuser and clean the
H/R(Heat Roller) and P/R(Pressure roller).
Check and clean the area between the
H/R and the Thermistor. (Caution: Take
care not to deform the rollers.)
7.3.15 Blank Page Print out (1)
• Description Blank page is printed.

Bad ground contacts in OPC and/or toner 1. Check if the Ground-OPC or the OPC
cartridge. Ground Zener diode are defective or open
circuit. (set inside left side).
2. Remove contamination of the terminals on

the toner cartridge and the unit.
7.3.16 Blank Page Print out (2)

1. Blank page is printed.
• Description 2. One or several blank pages are printed.
3. When the printer turns on, several blank pages print.

1. Abnormal solenoid. 1. Perform the engine self test using TECH
Mode to check if the Solenoid is normal.
If the problem persists replace the main
PBA
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Troubleshooting
7.4 Fax & Phone Problems
7.4.1 No Dial Tone
• Description There is no dial tone when the On-Hook dial button is pressed.

1. Check that the telephone line cord supplied with 1. If the telephone cord is OK but there is no dial tone, try
the set is connected to TEL LINE correctly. plugging a normal telephone into the wall socket. I this
is OK then replace the LIU B'd.
2. Listen for a CLICK sound when the OHD key is 2. If you cannot hear the OHD CLICK sound, the OPE
pressed. Ass'y may be defective. Replace the OPE Ass'y.
3. Check the connection of the HARNESS between 3. Check the Speaker connection and the harness
the LIU and the Main B'd. between the LIU and the Main PBA, replace as
necessary.
4. Check that the SPEAKER is connected correctly. 4. Use Tech mode / Modem Test to check that the
speaker and amplifier are working. Replace the Main B'd.
7.4.2 Defective MF DIAL
• Description The MF DIAL is not functioning.

1. Check that the telephone line cord supplied with 1. If the telephone cord is OK but there is no dial tone, try
the set is connected to TEL LINE correctly. plugging a normal telephone into the wall socket. I this
is OK then replace the LIU B'd.
2. Listen for a CLICK sound when the keKEY is 2. If you cannot hear the OHD CLICK sound, the OPE
pressed. Ass'y may be defective. Replace the OPE Ass'y.
3. Check the connection of the HARNESS between 3. Check the Speaker connection and the harness
the LIU and the Main B'd. between the LIU and the Main PBA, replace as
necessary.
4. Check that the SPEAKER is connected correctly.
4. Use Tech mode / Modem Test to check that the
speaker and amplifier are working. Replace the LIU
and Main B'd in sequence
Notes: Product supports MF DIAL type only.
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Troubleshooting
7.4.3 Defective FAX FORWARD/RECEIVE
• Description FAX FORWARD/RECEIVE is not functioning.

1. Check that you can hear a dial tone by pressing 1. If MODEM testing is normal and there is no dial tone,
OHD. then try replacing the LIU B'd.
2. Check that you can hear a RECEIVE tone when 2. If testing the MODEM shows a fault replace the
MODEM testing in TECH Mode. Main B'd.
7.4.4 Defective FAX FORWARD
• Description RECEIVE is functioning, but FORWARD is not functioning or received data is corrupt.

1. Check if there is a NOISE line by pressing on-hook 1. If you can hear a noisy line when using on-hook dial,
dial and listening. replace or repair the telephone line
2. Check that the destination fax machine can receive 2. Replace LIU.
forwarded faxes by using a different sending fax
machine (preferably from the same wall socket).
3. Check the cable between the set and the wall 3. Replace the line cord.
socket for damage.
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Troubleshooting
7.4.5 Defective FAX RECEIVE (1)
• Description FORWARD is functioning, but RECEIVE is not functioning or the received data is corrupt.

dial and listening replace or repair the telephone line.
2. Use a different fax machine to receive from the 2. Replace the LIU.
same sender (if possible on the same wall socket).
• Description Received data are lengthened or cut in the printing.

dial and listening replace or repair the telephone line
2. Ask sender to send to another fax machine 2. Replace LIU or main PBA in sequence.
(if possible connected to the same wall socket)
• Description The phone is ringing continuously, but it set does not answer the call.

Check that the RECEIVE Mode is set to FAX MODE. If the fault persists even when the RECEIVE Mode is
changed to FAX MODE then replace the LIU and the
Main B'd in sequence.
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Troubleshooting
• Description Received data is reduced by more than 50% in the printing.

Check the FAX status of the forwarding side. This is a problem with the sending fax machine.
Correct the setting on the remote machine..
7.4.9 Defective Automatic Receiving
• Description The automatic receiving function is not working.

1. Check that the RECEIVE Mode is set to FAX 1. If the RECEIVE Mode is set to the TEL MODE, reset it
MODE. to the FAX MODE.
2. Even after the RECEIVE Mode is changed to the FAX

Mode, the problem persists then try to replace the LIU
and the Main B'd in sequence.
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Troubleshooting
7.5 Copy Problems
7.5.1 White Copy
• Description Blank page is printed out when copying.

1. Check the Scanner Cover is properly closed. 1. Room light can pass through a thin original.
2. Check shading profile. 2. Redo shading profile in the tech mode.
3. Check white/black reference voltage on Main PBA. 3. Replace the Main PBA.
7.5.2 Black Copy
• Description Black page is printed out when Copying.

1. Check for CCD problem on the Main PBA. 1. Check the CCD harness is properly connected.
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Troubleshooting
7.5.3 Abnormal noise
• Description There is noise from the ADF when copying.

1. Check the Scanner Motor, gearbox and rollers. 1. Check for correct assembly of gears and motor.
Ensure no parts are fouling and there are no foreign
objects in the mechanism or scanner path. Replace
any worn parts
2. Check the Motor Driver on Driver PBA. 2. Replace the main PBA.
7.5.4 Defective Image Quality
• Description The copied image is excessively light or dark

2. Check the gap between original and scanner 2. A gap of more than 0.5 mm can cause a blurred
glass. image. Ensure rollers and cover close correctly.
Replace as necessary.
3. Check printing quality. 3. See "Print" troubleshooting.
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Troubleshooting
7.6 Scanning Problems – Causes and Solutions
7.6.1 PC Scanning problems
• Description Unable to scan using a PC.

1. Check the Cable (USB or Parallel) is properly 1. Reconnect the PC and printer, replace any faulty
connected and that the printer can print correctly. cables. If using a parallel cable, check that the par-
allel port is properly configured in the BIOS.
2. Check that the driver is installed properly. 2. If printing is OK check that the Scan driver is also
installed (Refer to User's Manual.)
3. Check that the copy function operates normally. 3. If the copy function works, replace the Main PBA.
If the copy function doesn't work, replace the CCD
Ass'y and try again.
7.6.2 Poor Quality of PC Scanned images
• Description The image PC scanned is not clear or bad.

1. Use TECH mode to carry out a shading test (see 1. If the CCD waveform form is abnormal replace the
page 6.15) and examine the waveform printout. CCD Ass'y.
2. Check if the resolution is set too low in PC Scan 2. Teach the user about scanner resolution – refer to
options. (Refer to User's Manual.) the User Guide.
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Troubleshooting
7.7 Toner Cartridge Service

Only toner cartridges supplied by Samsung should be used. Printing defects or set damage caused by the use of
non-approved toner cartridges or un-licensed toner refills are not covered by the guarantee.
7.7.1 Precautions on Safe-keeping of Toner Cartridge

Excessive exposure to direct light for more than a few minutes may cause damage to the cartridge.
7.7.2 Service for the Life of Toner Cartridge

If the printed image is light due to the toner supply becoming low you can temporarily improve the print quality by
redistributing the toner (Shake the toner cartridge), however you should replace the toner cartridge to solve the problem
permanently.
7.7.2.1 Redistributing Toner

When the toner cartridge is near the end of its life, white streaks or light print occurs. The LCD displays the warning mes-
sage, “Toner Low.” You can temporarily reestablish the print quality by redistributing the remaining toner in the cartridge.
1. Open the Front Cover. 3. Unpack the new toner cartridge and gently shake it hor-
izontally four or five times to distribute the toner evenly
inside the cartridge.
4. Save the box and the cover for shipping. Slide the new
toner cartridge in until it locks into place.
2. Lightly pushing the used cartridge down, pull it out.
Note : Help the environment by recycling your used toner car-

tridge. Refer to the recycling brochure packed with the
toner cartridge for details.
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Troubleshooting
7.7.3 Standard of guarantee for consumable parts.
Please refer to User's Manual or Instructions on Fax/Printer Consumables SVC manual for the criteria for judging the
quality of consumable parts the standard of guarantee on those parts.
• Spotting a refilled cartridge by eye.

One way security screws are used in the manufacture of the cartridge – check if these are damaged.
7.7.4 Error messages in the LCD window related to toner.

This section explains messages on the LCD that are related to the data stored in the EEPROM in the toner cartridge.
7.7.4.1 Toner Low

- Explanation: The amount of toner remaining is less than 10%
- Solution: The cartridge is almost empty or life-expired – replace the cartridge.
7.7.4.2 Toner Empty

- Explanation: The toner cartridge is empty
- Solution: Replace the cartridge.
7.7.4.3 Drum Warning

- Explanation: This message appears when the OPC drum is nearing the end of its life (14,000pages). This means
that the life of the mechanical parts in the cartridge has expired (this is not an indication of toner remaining).
- Solution: After printing about 15,000 pages, in a worst case scenario, the waste toner collector might overflow and it
may cause the system to fail. Also after 15,000 pages the OPC drum surface will be becoming worn and print quality
will degrade, print images will become misty. It is therefore necessary to replace the cartridge even though there may
be toner left in it.
When this message occurs there are approximately 1,000 pages left.
7.7.4.4 Replace Drum

- Explanation: The toner cartridge mechanical life is expired.
- Solution: Replace the cartridge.
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Troubleshooting
7.7.5 Signs and Measures of Poor toner cartridge
Fault Signs Cause & Check Solution
Light image and • The printed image 1. If the image is light or dirty 1. All of 1, 2, 3
partially blank is light or dirty and and untidy - Shake the toner If image quality improves by
image untidy. cartridge and then recheck. shaking, replace with a new
(Cartridge life is OK: Lack of toner, so the life toner cartridge. Perhaps up to
ended.) • Parts of the image is nearly expired. 100 pages left before out of
are not printed. toner.
Digital Printer 2. Some part of image is not
Digital Printer • Periodically a "tick printed - Shake the toner 2. For item 2-
Digital Printer tick" noise occurs. cartridge and then recheck. If image quality improves after
(1)NG: clean the LSU window cleaning the LSU window then
Digital Printer with a cotton swab, then the toner cartridge is normal.
Digital Printer recheck. (Contamination on the LSU
(2)OK: Lack of toner, so the window has caused image
life is nearly closed. quality problems.)
3. Periodically a noise like "tick 3. For item 3-

tick" occurs - Measure the If the time between ticks is
time between ticks. about 2 seconds, the toner
inside the toner cartridge is
4. White vertical stripes on the almost exhausted.
whole or part of the page : ( Purchase and replace with a
Shake the toner cartridge and new toner cartridge. Perhaps up
then recheck. OK: Lack of to 200 pages left before out of
toner, so the life is nearly toner)
expired
4. For item 3-
This is a phenomenon caused
by lack of toner, so replace the
toner cartridge.
Toner • Toner 1. Contamination at regular 1.(a) Refer to section 7.6

Contamination contamination of intervals.
the printed page at (a)Check the distance 1.(b) If both ends of the OPC drum
regular intervals between contamination are contaminated with toner:
down the page. marks. Check no. of pages printed using
(b)Check the appearance of this cartridge – perhaps waste
• Random Toner both ends of the toner toner collector is full.
contamination over cartridge OPC drum.
the whole or large
parts of the paper 2. Random page contamination. 2. Clean all HV contacts. If the
surface. (a) Check that the terminals problem persists replace the
(contact points) of the toner cartridge.
cartridge and the set are
clean.
(b) Check that the terminals
(contact points) of the toner
cartridge and the set are not
damaged.
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Troubleshooting
White Black spot • Light or dark black 1. If light or dark black dots 1. For item 1 -
dots on the image occur at regular intervals this Run OPC Cleaning Mode Print
occur periodically. is because the toner cartridge 4-5 times repeatedly to remove
Digital Printer rollers are contaminated with excess toner. Especially check
Digital Printer • White spots occur foreign substance or paper for foreign substances on the
Digital Printer in the image particles. OPC surface Clean with a clean
Digital Printer periodically. (1)38mm interval : Charge gauze moistened with IPA
Digital Printer roller Isopropyl Alcohol) take care not
(2)95mm interval : OPC cycle to damage the OPC surface.
2. If white spots occur in a black Never use other forms of alcohol.

image at intervals of 95mm,
or black spots occur 2. For Item 2 -
elsewhere, the OPC drum is If running OPC Cleaning Mode
damaged or foreign Print 4-5 times does not resolve
substance is stuck to the the problem
surface. : at intervals of 37.7mm - place
the toner cartridge.
3. If a black and white or : at intervals of 75.5mm – clean
graphic image is partially OPC drum.
broken at irregular intervals,
the transfer roller's life has 3. For item 3 - Change the transfer
been expired or the transfer roller because the life of the
voltage is abnormal. transfer roller has expired.
(Check the transfer voltage and
readjust if necessary.)
Recycled product • Poor appearance of 1. Poor appearance of the toner 1. For Item 1 the cartridge is judged
the toner cartridge. cartridge. to be a recycled product -
(a)Check for damage to label (a) If there is any evidence of
• Dirty or rough and if different materials are disassembling the toner cartridge.
printouts. used. (b) If materials other than normal
(b)Check the appearance of parts of the toner cartridge are
• Bad background in parts of the toner cartridge, added or substituted.
the image. such as frame, hopper, screws
2. Clean all HV contacts. If the
problem persists replace the
2. Unclean and rough printouts. cartridge.
(a)Check that the terminals
(contact point) of the toner Note If the cartridge is judged to be
cartridge and the set are clean. recycled then these types of
(b)Check that the terminals problems can occur when the
(contact point) of the toner toner cartridge is recycled over
cartridge and the set are not 2 times.
damaged.
If ‘nearly empty’ cartridges are
collected for re-use this is
judged as recycling the toner
cartridge.
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Troubleshooting
Ghost & Image • The printed image 1. The printed image is too light 1. All of Items 1, 2, 3
Contamination is too light or dark, or dark, or partially (a) Clean the contacts on the
or partially contaminated black. toner cartridge.
contaminated black. (a) Check if foreign substance (b) Clean the contact points on
or toner are stuck to the the set.
• Totally terminals (point of contact) (c) If the terminal assembly is
contaminated black. of the toner cartridge or set. damaged repair or replace
(Black image (b) Check if the terminal the terminals in the set or
printed out) assembly is normal. replace the cartridge
• The density of 2. Totally contaminated black. 2. In Item 2

printouts is too dark (Black image printed out) This is particularly related to
and ghost occurs. (a) Check if foreign problems with the charge roller
substances are stuck to contact. Pay close attention to
the terminal (point of the charge roller contacts.
contact) of the toner
cartridge or set. 3. In Item 3
(b) Check if the terminal This is particularly related to
assembly is normal. problems with the developer
(Especially check the bias voltage contact. Pay close
charge roller terminal.) attention to the charge roller
contacts.
3. The printed image is dark and
ghost occurs.
(a) Check if foreign
substances are stuck to
the terminal (point of
contact) of the toner
cartridge or set.
(b) Check if the terminal
assembly is normal.
(Especially check the
developer roller terminal.)
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Troubleshooting
7.8 Software Problems – Causes and Solutions
7.8.1 The printer is not working (1)
• Description While Power turned on, the printer is not working in the printing mode.

1. Run Self-Test Mode: using the menu buttons print the 1. If the test print works that means there are no
test page. (Menu, Enter, Enter). problems in the printer itself. If the test printing does
not work that means the printer is faulty and the
problem is not due to computer software or driver
settings.
2. Check that the PC and the printer are properly 2. Replace the printer cable. If the problem is not
connected and that the toner cartridge installed solved even after the cable is replaced, check the
correctly. amount of the remaining toner. (refer to Toner
Cartridge Service 7-6, Page 7-25)
3. Printing is not working in the Windows. 3. Check that the connection between PC and printer
port are correcct. If you use windows, check that the
printer driver in the controller is set up correctly set
up, the correct port is selected and ‘Use On-line’ is
selected in the driver. If the printer driver is properly
set up try printing a test page from the driver proper-
ties. Check in which program printing is not working.
Try opening ‘Memo Pad’ and printing. If the printer
is not working in a certain program, adjust the setup
within that program.
Sometimes, the printout is normal within the
Windows basic programs, but it's not working in a
particular program. In this case, uninstall and re-
install the new driver. If the printer is not working in
the Windows basic programs and you are printing
using the parallel port check the port setting in
CMOS is on ECP and that the address is IRQ 7
and 378 (for parallel port 1). Try using USB instead
of parallel – or vice versa.
4. Check that the printer cable is directly connected to the 4. If you have other devices that need to share the
printer. printer port try temporarily disconnecting these
devices 9and perhaps even uninstalling their dri-
vers) to ensure the printer works by itself. If you are
using a USB hub try connecting directly to the back
of the PC instead.
Service Manual
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Samsung Electronics
Troubleshooting
7.8.2 The printer is not working (2)
• Description After receiving the print command there is no response at all or print speed is low
due to wrong setup of the environment rather than malfunction of the printer itself.

1. Ensure you have sufficient free hard disk space for the 1. Not working with the message 'insufficient printer
temporary work files created during printing. memory' means there is a hard disk space problem
rather than a printer RAM problem. In this case pro-
vide more space on the hard disk. Secure more
space using the disk utilities program.
2. Printing error occurs even if there is enough space in 2. The connection of the cable and printer port is not
the hard disk. correct. Check that the cable is properly connected
and if you are using the parallel port check that the
port settings in CMOS is correct.
3. Check the parallel-port-related items in the CMOS 3. For the printer port, Select ECP. SPP and normal
Setup. normal modes support 8-bit data transfer, while
ECP Mode supports 12-bit data transfer.
4. Reboot the system to print. 4. If the regular font is not printing, the cable or the
printer driver may be defective.
Turn the PC and printer off, and reboot the system
to print again. If not solved, double-click the printer
in my computer If the regular fonts are not printed
this time again. the cable must be defective so
replace the cable with new one.
Service Manual
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Samsung Electronics
manuals4you.com
Troubleshooting
7.8.3 Abnormal Printing
Printing does not work – even after replacing the cable

• Description
Printer does not work at all or strange fonts are printed,

1. Set up the parallel port using CMOS SETUP. 1. Ensure that ECP (best) or SPP is selected in the
CMOS (BIOS) setup.
2. Printer Driver Error. 2. Ensure that the correct driver is loaded. Use the
driver supplied on the CD or downloaded from the
Samsung web site. DO NOT use the Microsoft
driver supplied with the Windows operating system.
If the printer is a GDI or SPL type printer ensure that
ALL OTHER GDI or SPL drivers are uninstalled as
Windows allows only 1 of this type of driver to be
loaded.
3. Error message “insufficient memory”. 3. Delete any unnecessary files to secure enough
(The printing job sometimes stops due to insufficient space on the hard disk and start the print job again.
virtual memory, this is caused by insufficient space on
the hard disk.)
Service Manual
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Samsung Electronics
Troubleshooting
7.8.4 SPOOL Error
SPOOL (simultaneous peripheral operations online) is the process Windows uses to

• Description manage print jobs. Jobs are processed and then stored on the hard disk until the printer is
ready to accept them

1. Insufficient space on the hard disk in the directory 1. Delete any unnecessary files to provide more space
assigned for the basic spool. for spool storage.
2. If previous printing errors were not solved. 2. There may be files from previous failed print jobs on
the hard disk with the name in the form ‘*.jnl’.
Delete these files and Reboot Windows to restart
the printer.
3. There may be conflict with other drivers or programs. 3. Shut down all other programs except the current
one, if possible.
4. When an application program or the printer driver is 4. Delete the printer driver completely and reinstall it.
damaged.
5. When some files related to the OS are damaged or 5 After rebooting the computer, check for viruses,
virus infected. restore the damaged files and reinstall the
application program which is not working properly.
6. Memory is less than suggested. 6. Add up more memory to the PC.
How to delete the data in the spool manager.
In the spool manager, the installed drivers and the list of the documents waiting to be printed are shown.
Select the document to be deleted and check delete in the menu.
If the job you are deleting is the current job when you delete the job data that has already been transferred to
the printer’s memory will still be printed. If there is a problem with the printer (out of toner, offline, out of paper
etc.) the job may take a long time to delete as it must wait for a time out.
Service Manual
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manuals4you.com
Troubleshooting
7.9 Network Problem Troubleshooting
7.9.1 General Problems
Problem Solution
Incorrect setup can cause network errors. Possibly the parameters in PortThru (the network card) are corrupt-
ed. Restart the system and reset the printer network settings to fac-
tory defaults using the printer front panel or by using SyncThru on
your computer.
SNMP Manager cannot access the printer. Using the SNMP manager computer try pinging the printer. If it
does not succeed there must be a problem with network connectivi-
ty between the SNMP manager computer and PortThru. If ping suc-
ceeds verify that community names entered into the PortThru set-
tings are spelled correctly and have sufficient permissions.
The printer does not obtain an IP address If there is an IP address server on your network ensure that there
from a BOOTP, RARP or DHCP server. are no VLAN, Access Control Lists or other network settings pre-
venting communication. Remember these protocols are generally
not routable unless specifically setup in a router.
Where no address server exists use SyncThru or the control panel
on the printer to select "Static" IP Address Assignment Method" in
TCP/IP tab. You should set IP address, Subnet Mask and Default
Gateway in the printer using SyncThru, printer control panel or
browser methods (see the user guide).
Print server does not print using TCP/IP protocol. 1. Check that TCP/IP protocol is installed and properly configured in
your PC.
2. Check whether your PC is on the same network with print server
(IP addresses and subnet masks must be properly set in the PC
AND in the printer).
Unable to print in a NetWare environment. Use SyncThru to see if PortThru indicates that queue is service-
able. If not, the login permissions may have changed or the config-
uration information for queues, printers and print servers may have
been changed. Verify using PCONSOLE and NWADMIN that the
configuration is correct and check the job queue to see if the print
job exists. Check that NetWare is enabled on PortThru. Check that
the Check Job very is configured on PortThru.
The name of printer is not displayed when 1. Check that the protocol settings on your computer are correct.
adding a port and the printer doesn't function. 2. Assign an IP Address to PortThru using the front panel,
SyncThru or browser methods (see the user guide).
Service Manual
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Samsung Electronics
Troubleshooting
7.9.2 Windows Problems
Problem Solution
After installing PortThru the print server name 1. Verify that the printer power switch is turned on and the 'READY'
is not displayed under New Print Server in message is displayed on the printer front panel.
SyncThru. 2. Verify that the LAN cable is plugged into the PortThru card.
3. There are 2LEDs on the PortThru card. One should flash irregularly
and the other should be on. If this is not the case ensure that the
network card is properly installed and the PCB an cable connectors
make a good connection. If the problem continues check the network
cable / socket by using a different cable or socket. If the problem
continues replace the network card.
4. Confirm that the print server and the PC which searches for the
New Print Server is on the same LAN (correct IP and subnet
mask settings). If you want to search for a New Print Server your
PC and the print server should be on the same LAN.
The print server name is displayed, but the test Using the front panel menus print the Network configuration. If the
page is not printed. Network menu is not displayed or the configuration page is not
printed turn off the printer, ensure the network card is properly fitted
then turn it back on and try again. If the problem continues replace
the network card.
SyncThru indicates that firmware upgrade is Before attempting to upgrade firmware ensure that computer and
complete but when the network configuration printer can communicate using a Ping command.
is printed the software version has not changed.
SycThru is unable to automatically detect 1. Check that the LAN cable is connected to the printers. If an IP
the printer. address is assigned to the computer and printer ensure that the
Ping command can see the printer.
If an IP address is not allocated to the printer or it is in a different
LAN segment then ensure that either IPX/SPX or DLC/LLC pro-
tocols are enabled on the computer.
2. Print the network configuration. If the TCP/IP or Network proto-
cols are disabled in the printer either use the front panel to re-
enable them or ensure that DLC/LLC protocol is installed in the
computer.
3. In SyncThru use the Settings / Protocol Selection menu option to
select either TCP/IP or IPX protocols and then use the
View/Refresh option to scan the network again.
4. Ensure that the network cable and wall socket are functioning
correctly.
5. Ensure that the version of SyncThru is the same as or newer
than the version supplied with the printer.
6. Ensure that there is no router between the printer and the
computer as SyncThru will not work through a router.
7. Ensure there are no Switch or Router VLAN or Access Control
Lists which are blocking communication between the printer and
the computer.
Note Windows XP does not support DLC/LLC protocols.
The printer does not print via a 1. Connect the printer using a Parallel or USB cable and ensure
network connection. that the computer can print. If not check that the printer drivers
are installed correctly
2. If the printer can print via a local connection check Printer
Properties / Ports and ensure that a TCP/Ip port has been allo-
cated to the printer.
Service Manual
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manuals4you.com
Troubleshooting
7.9.3 SyncThru Installation Problems
Problem Solution
"File Transfer Error" message appears during 1. Make sure that any previously installed version of SyncThru is
the Installation process. uninstalled. Restart your PC after uninstalling previous versions.
2. If the problem continues, In Windows 95/98 boot into MS/DOS
mode and delete the "sammon.dll" file in the windows\system
directory the restart Windows and reinstall SyncThru. In Windows
NT stop the spooler service using' Services 'in Control Panel,
delete the "sammon.dll" file in the windows\system32 directory
then restart the spooler service and reinstall SyncThru.
'Unable to add the Port list of Samsung ports' Verify that your PC restarts after installing SyncThru.
message appears when you add a port.
.c om
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Service Manual
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Samsung Electronics
Exploded View & Parts List
8
Up-date On August. 2. 2004
8. Exploded Views and Parts List

8.1 Main Assembly Exploded view ............................................................................... page(8-2)
8.2 Rx Drive Ass’y Exploded view ................................................................................ page(8-5)
8.3 ADF Assembly Exploded view ................................................................................ page(8-6)
8.4 OPE Assembly Exploded view ................................................................................. page(8-10)
8.5 Scanner Assembly Exploded view ......................................................................... page(8-12)
8.6 Middle Cover Assembly Exploded view ................................................................. page(8-14)
8.7 Frame Ass’y Exploded view .................................................................................... page(8-15)
8.8 Fuser Ass’y Exploded view ..................................................................................... page(8-19)
8.9 MP Assembly Exploded view .................................................................................. page(8-21)
8.10 Cassette Ass’y Exploded view .............................................................................. page(8-23)
8.11 SCF(Option Cassette Frame) Exploded view ....................................................... page(8-25)
Exploded drawings and service parts lists are given for items which may
be expected to have a higher failure rate.
Where a failure occurs you can identify the part in the exploded diagram
and, using the parts cross reference number, refer to the appropriate parts
list to identify the part number.
Note : Parts numbers given here are correct at the time of publication.
When ordering parts please use the on-line ordering system to check if
there have been any changes to part numbers.
Part Number & Description format.
Part numbers and descriptions are defined according to a company standard. The information below
will help you to understand the part number format and assist when ordering spare parts.
There are two types of Part number format.
number letter
This format is used throughout Samsung on all product ranges.

Typically it is used for small components and electronic parts.
This format is controlled by individual Samsung Divisions and is used on specific

products, typically for mechanical parts. Type 2 format part numbers fall into 2 categories:
Assemblies consisting of 2 or more parts. Also used for Service manuals,

user guides and diagrams.
Ass’y parts and A/S privately used Parts can be distinguished by the part Code and Description.
They are always Type 2 format. The 2 leading characters indicate private or assembly parts.
Service Manual
8-1
Samsung Electronics
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8-2
0
7
9
24
23 23-2
Service Manual
21-1
21-2 5
8
SCX-4520
23-1
17 17-1
25
21-4 21 4 17-2
8.1 Main Assembly
21-3
SCX-4720F
22-3 22-11 16
22-2 3 26
1 22-4 22-1
22
22-12
1-1
22-5
22-6 2
15
14
22-7 27
SCX-4720F 22-8
22-13
22-10
SCX-4520
22-9
1-2 13
12
18
1-3
1-2
19-4 6
19-1
19-2
Toner Cartridge SCF
1-4 19-3 11
19
20 10
Samsung Electronics
Main Assembly Parts List

SA : Service Available
O : Service available X : Service not available
No. Description SEC.Code Q’ty SA Remark

0 SCX-4520
SCX-4720F
1 ELA HOU-SCAN JC96-03181A 1 X SCX-4520
ELA HOU-SCAN JC96-03184A 1 X SCX-4720F
1-1 ELA HOU-ADF JC96-03169A 1 O
1-2 ELA HOU-OPE JC96-03183A 1 O SCX-4520
ELA HOU-OPE JC96-03174A 1 O SCX-4720F
1-3 COVER-M-OPE FRONT JC63-00496A 1 O
1-4 ELA HOU PLATEN JC96-03172A 1 O
2 FRAME-M-BASE JC61-00906A 1 X
3 ELA UNIT-RX DRIVE JC96-03078A 1 O
4 UNIT-HUMMINGBIRD LSU JC59-00018B 1 O
5 CBF HARNESS-LSU JC39-00395A 1 O
6 SMPS-V1 JC44-00070A 1 O 110V
SMPS-V2 JC44-00071A 1 O 220V
7 PBA MAIN-MAIN CONTROLLER JC92-01597A 1 O SCX-4720F
PBA MAIN-MAIN CONTROLLER JC92-01598A 1 O SCX-4520
8 SHIELD-P-CONTROLLER JC63-00508A 1 X
9 BRACKET-P-DUMMY CTRL JC61-00679A 1 X
10 MEA UNIT-SHIELD ENGINE JC97-01943A 1 X
11 BRACKET-P-INLET JC61-00693A 1 X
12 CBF HARNESS-HIGH LIU JC39-00325A 1 O
13 PBA SUB-LIU JC92-01599A 1 O RUSSIA
PBA SUB-LIU JC92-01599B 1 O EU/SER
PBA SUB-LIU JC92-01599C 1 O AUSTRALIA
14 COVER-M-SIDE R JC63-00499A 1 O
15 ELA UNIT-MP JC96-03132B 1 O
16 CBF HARNESS-MOTOR JC39-00355A 1 O
17 MEA ETC TR JC97-01917A 1 O
17-1 ROLLER-TRANSFER R2 JC66-00703A 1 X
17-2 GEAR-TRANSFER JC66-00395A 1 X
18 ELA HOU-COVER MIDDLE JC96-03247A 1 O
19 MEA-COVER MID FRONT JC97-02043A 1 O
19-1 COVER-M-MID FRONT JC63-00497A 1 O
19-2 CAP-M-SUB ACTUATOR JC67-00068A 1 X
19-3 PMO-M-SUB ACTUATOR JC72-01339A 1 X
19-4 SCREW-TAPTITE 6003-000196 1 X
Service Manual
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Samsung Electronics
manuals4you.com
Main Assembly Parts List


20 MEA UNIT-CASSETTE JC97-02020A 1 O
21 ELA HOU-COVER SIDE L JC96-03185A 1 O
21-1 COVER-SIDE L JC63-00500A 1 X
21-2 COVER-DIMM JC63-00501A 1 X
21-3 SPEAKER 3001-001591 1 O
21-4 SCREW-TAPTITE 6003-000264 2 X
22 MEA-COVER FRONT JC97-02019A 1 O
22-1 COVER-M-FRONT JC63-00505A 1 O
22-2 KNOB-M-LOCKER JC64-00154A 1 X
22-3 HOLDER-M-LOCKER JC61-00953A 1 O
22-4 TRAY-M-EXIT-MP JC63-00447A 1 X
22-5 ADJUST-M-MP L JC70-00478A 1 X
22-6 ADJUST-M-MP R JC70-00479A 1 X
22-7 TRAY-M-COVER_MP JC63-00446A 1 X
22-8 GEAR-PINION JG66-40003A 1 O
22-9 TRAY-M-CASE_MP JC63-00506A 1 X
22-10 TRAY-M-LINK_MP JC63-00444A 2 X
22-11 SPRING-CIS(2) JG61-70549A 1 X
22-12 SCREW-TAPTITE 6003-000196 2 X
22-13 SCREW-TAPTITE 6003-000264 1 X
23 MEA -COVER REAR JC97-02018A 1 O
23-1 COVER-M-REAR JC63-00503A 1 O
23-2 COVER-FACE UP JC63-00504A 1 O
24 CBF HARNESS ENGINE JC39-00240C 1 O
25 CBF HARNESS-LSU GND JC39-00375A 1 O
26 ELA HOU-FUSER 110V JC96-03210A 1 O 110V
ELA HOU-FUSER 220V JC96-03260A 1 O 220V
27 FAN-DC JC31-00025A 1 O
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Samsung Electronics
8.2 RX Drive Assembly
4
2
5
4 5
RX Drive Assembly Parts List


0 ELA UNIT-RX DRIVE JC96-03078A 1 O
1 BRACKET-GEAR MAIN JC61-00891A 1 X
2 GEAR-RDCN 53/26 JC66-00388A 1 O
3 GEAR-RDCN 113/33 JC66-00706A 1 X
4 GEAR-RDCN 57/18 JC66-00389A 2 O
5 WASHER-PLAIN 6031-000023 2 X
6 BRACKET-MOTOR MAIN R2 JC61-00916A 1 X
7 GEAR-RDCN 103/41 JC66-00390A 1 O
8 GEAR-RDCN 90/31 JC66-00392A 1 O
9 MOTOR STEP-MAIN JC31-00037A 1 O
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8.3 ADF Assembly
5
5-1
5-2
5-3
6
6-3
5-2 6-1 0 : Service Part
*ELA HOU-ADF_R2
6-2 (JC96-03169A)
ADF ASS’Y
1-2-4 1
1-2-1
1-2
1-2-2
1-2-3
4
1-1
3-5 3-6 3-14

2-16 3-4 3-18
3-3 3-11
3-7 3-7
3-8 3-9
3-16 3-18
3-15
2-3
3-17
3-10
3-16
3-13 3-18
3-19 3-20
2-2 3-21
2-15 2-4
2-6 3-1
3-12 3-2
2-7 2-5
2-8 3-19
2-9
2-15
2
3
2-17
2-1
2-19
2-22
2-12 2-18
2-10
2-22
2-20 2-19
2-13
2-20
2-21
2-14
Service Manual
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Samsung Electronics
ADF Assembly Continued.
4-3-2
4-3-3
4-3-4 4-3-5
4 : Service Part
*MEA-COVER PLATEN
(JC-97-02024A)
4-3-1
4-3
4-8
4-6
4-4
4-7
4-7
4-1
4-4
4-5
4-9
4-2
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manuals4you.com
ADF Assembly Parts List


0 ELA HOU-ADF-R2 JC96-03169A 1 O
1 MEA UNIT-ADF UPPER JC97-02022A 1 X
1-1 COVER-ADF UPPER R2 JC63-00450A 1 O
1-2 MEA-HOLDER PAD ADF JC97-02137B 1 O
1-2-1 RMO-ADF RUBBER JB73-00052A 1 X
1-2-2 HOLDER-PAD ADF JC61-00893A 1 X
1-2-3 SPRING ETC-PAD JC61-00387A 1 X
1-2-4 SHEET-ADF HOLDER JC63-00373A 1 X
2 ELA HOU-ADF LOWER JC96-03171A 1 X
2-1 COVER-M-ADF LOWER R2 JC63-00370B 1 O
2-2 PBA SUB-ADF JC92-01618A 1 O
2-3 GROUND-P-ADF R2 JC63-00372A 1 X
2-4 SHAFT-M-FEED GEAR 38 JC66-00460A 1 X
2-5 ROLLER-DRIVE JC66-00560A 1 X
2-6 PMO-ACT EMPTY ADF JC72-01320A 1 O
2-7 PMO-ACTUATOR REGI SENSOR JC72-01010A 1 O
2-8 PMO-ACTUATOR SCAN SENSOR JC72-01011A 1 O
2-9 SPRING ETC-TORSION DOC (CC2-F) JB61-00076A 3 X
2-10 IPR-GROUND_ROLLER JC70-10467A 1 X
2-12 ROLLER-EXIT JC66-00559A 1 X
2-13 MEC-BRUSH ANTISTATIC JC75-00095A 1 X
2-14 PPR-WHITE BAR SHEET JC72-00752A 1 X
2-15 PMO-BUSH JB72-00819A 4 X
2-16 CBF HARNESS-ADF JC39-00351A 1 O
2-17 GEAR-AGITATOR-2 JC66-00310A 1 X
2-18 RING-C 6044-000159 1 X
2-19 GUIDE-STACKER SUB JC61-00712A 2 X
2-20 CBF HARNESS ADF ROLLER GND JC39-00187A 1 X
2-21 IPR-BRKT WHITE BAR JC70-00225A 1 X
2-22 SPRING ETC WHITE BAR JC61-00548A 2 X
3 ELA HOU-ADF MOTOR JC96-03065A 1 O
3-1 BRACKET-GEAR ADF JC61-00892A 1 X
3-2 MOTOR STEP-ADF JC31-00036A 1 X
3-3 GEAR-CLUTCH 29 JB66-00101A 1 X
3-4 PMO-WHITE CLUTCH SUB 29 JB72-00844A 1 X
3-5 GEAR-CLUTCH 39 JC66-00322A 1 X
3-6 RING-C 6044-000159 1 X
3-7 GEAR-IDLE 35 ADF JC66-00458A 2 X
3-8 GEAR-40/21 ADF JC66-00456A 1 X
Service Manual
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Samsung Electronics
ADF Assembly Parts List(cont.)


3-9 GEAR-SWING 31/20 ADF JC66-00457A 1 X
3-10 LINK-M-SWING ADF JC66-00454A 1 X
3-11 GEAR-58/25 ADF JC66-00455A 1 X
3-12 IMPELLER-ADF JC66-00556A 1 X
3-13 GEAR-REMOVE ADF JC66-00557B 1 X
3-14 WASHER PLAIN 6031-000023 1 X
3-15 IPR-WASHER WAVE JB70-00070A 1 O
3-16 WASHER-PLAIN 6031-000019 2 X
3-17 CBF HARNESS-ADF GND JC39-00363A 1 X
3-18 RING-E 6044-000125 6 X
3-19 SCREW-TAPTITE 6003-000269 3 X
3-20 WASHER-PLAIN 6031-001511 1 X
3-21 SPRING ETC PAD JC61-00387A 1 X

4 MEA-COVER PLATEN JC97-02024A 1 O
4-1 COVER-M-PLATEN R2 JC63-00374B 1 O
4-2 SHEET-WHITE SPONGE JC63-00209A 1 O
4-3 MEA-TX STACKER JC97-01544B 1 O
4-3-1 PMO-TX STACKER JB72-01166B 1 O
4-3-2 PMO-DOC GUIDE(L) JB72-01171B 1 X
4-3-3 GEAR-PINION JG66-40003A 1 O
4-3-4 PMO-DOC GUIDE(R) JB72-01170B 1 X
4-3-5 IPR-WASHER SPRING CU JF70-10616A 2 X
4-4 SPRING ETC-FEED JC61-00011A 6 X
4-5 PMO-ROLL PINCH JG72-40663A 2 X
4-6 ICT-SHAFT PINCH JF70-40521B 1 X
4-7 MEA UNIT-HINGE JC97-01707A 2 O
4-8 RPR-ROLLER EXIT IDLE JC73-00091A 2 O
4-9 SHAFT-IDLE FEED JC66-00558A 2 O
5 MEA-COVER OPEN R2 JC97-02023A 1 X
5-1 COVER-M-ADF OPEN JC63-00498A 1 O
5-2 PMO-GUIDE PAPER JB72-00843A 2 X
5-3 DAMPER-PICKUP ADF JC66-00726A 1 X
6 MEA UNIT-PICKUP JC97-01962A 1 O
6-1 STOPPER-M-PICKUP ADF JC61-00963A 1 X
6-2 GEAR-ADF 38 JB66-00103A 1 X
6-3 RING-C 6044-000159 1 X
Service Manual
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8.4 OPE Unit Assembly
(SCX-4520) (SCX-4720F)
0 0
21
2
20
1
2
1
8
10 19
5 8
3
4
5
6 3 4
17
7 10
18
9 6 16
15
11 7
14 9
11
12
12
13
13
Service Manual
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Samsung Electronics
OPE Unit Assembly Parts List

[SCX-4520 ] O : Service available X : Service not available

0 ELA HOU-OPE 3IN1 JC96-03174A 1 O
1 COVER-M-OPE (3IN1) JC63-00496A 1 O
2 WINDOW-LCD_R2_SEC2 JC64-00171B 1 X
3 KEY-M_COPY(3IN1) JC64-00054C 1 X
4 KEY-M-STOP JC64-00055A 1 X
5 KEY-M_SCROLL_R2 JC64-00056D 1 X
6 KEY-M-START(3IN1) JC64-00057B 1 X
7 KEY-M-TONER SAVE JC64-00058A 1 X
8 KEY-M_RESOLUTION_R2 JC64-00059C 1 X
9 KEY-M-DIRECT PRINT JC64-00155A 1 X
10 KEY-M-SCAN TO JC64-00157A 1 X
11 RUBBER-COPY/SCROLL JC73-00189A 1 X
12 RUBBER-COPY_3IN1 JC73-00192A 1 X
13 PBA SUB-OPE JC92-01625A 1 O
S SCREW-TAPTITE 6003-000196 7 X
[SCX-4720F ]
0 ELA HOU-OPE 4IN1 JC96-03174A 1 O
1 COVER-M-OPE SEC JC63-00495A 1 X
2 WINDOW-LCD_R2_SEC JC64-00171A 1 X
3 KEY-M_COPY_R2 JC64-00054C 1 X
4 KEY-M-STOP JC64-00055A 1 X
5 KEY-M_SCROLL_R2 JC64-00056D 1 X
6 KEY-M-START JC64-00057E 1 X
7 KEY-M-TOLL SAVE JC64-00061A 1 X
8 KEY-M_RESOLUTION_R2 JC64-00059C 1 X
9 KEY-M-DIRECT PRINT JC64-00155A 1 X
10 KEY-M-SCAN TO JC64-00157A 1 X
11 RUBBER-COPY/SCROLL JC73-00189A 1 X
12 RUBBER-TELL/FAX_SEC JC73-00191A 1 X
13 PBA SUB-OPE_4720F JC92-01625A 1 O
14 RUBBER-ONE TOUCH JC73-00190A 1 X
15 KEY-M-TONER SAVE JC64-00058A 1 X
16 KEY-M_FAX_R2 JC64-00060C 1 X
17 KEY-M-SHIFT JC64-00156A 1 X
18 KEY-M_TEL_R2 JC64-00053D 1 X
19 PMO KEY OT JC72-00275B 1 X
20 LABEL(P)-ONE TOUCH JC68-00651G 1 X
21 MPR-COVER ADDRESS JG74-10543A 1 X
S SCREW-TAPTITE 6003-000196 10 X
Service Manual
8-11
Samsung Electronics
manuals4you.com
8.5 Scanner Assembly
1-3-1 1-3
1-3-2
1-3-4
1-3-3
1-1 0
1
1-5
1-4
1-5
1-2
2-15 2-2
2-15-4
2-9
2-15-3 2-5
2-15-7
2-15-6
2-15-5 2-3
? 2-15-8
2-10
2-11
2-15-1 2-8 2-6
2-13
2-12 2-7
2-15-2 2-16
2-4
2-1
2-14
Service Manual
8-12
Samsung Electronics
Scanner Assembly Parts List


0 ELA HOU-PLATEN JC96-03172A 1 O
1 MEA UNIT-SCAN UPPER JC97-02025A 1 O
1-1 COVER-SCAN UPPER JC63-00494A 1 X
1-2 GLASS-SCAN JC01-00001A 1 O
1-3 MEA-SCAN DUMMY JC97-02026A 1 X
1-3-1 COVER-M-SCAN DUMMY R2 JC63-00152E 1 X
1-3-2 MCT-GLASS ADF JC74-00021A 1 X
1-3-3 TAPE-DOUBLE FACE 0203-001266 1 X
1-3-4 LABEL(P)-SHADING JB68-00644A 1 X
1-4 IPR-HOLDER GLASS JB70-00148A 2 X
1-5 SCREW-TAPPING 6002-00175 2 X
2 ELA HOU-SCAN LOWER JC96-03173A 1 X
2-1 COVER-SCAN LOWER JC63-00493A 1 O
2-2 ELA HOU-CCD MODULE JC96-02759B 1 O
2-3 CBF SIGNAL-CCD FFC JC39-00367A 1 X
2-4 ICT-INSERT SHAFT JB70-00154A 1 X
2-5 ICT-SHAFT CCD JB70-00145A 1 X
2-6 PMO-HOLDER BELT JB72-00764A 1 X
2-7 PMO-PULLEY JB72-00763A 1 X
2-8 ELA UNIT-CORE JB96-01381A 3 X
2-9 SPRING ETC-BELT JB61-00059A 1 X
2-10 BELT-TIMING GEAR 6602-001067 1 O
2-11 PMO-LEVER SENSOR JC72-00755A 1 X
2-12 PHOTO-INTERRUPTER 0604-001095 1 O
2-13 SPRING-CS 6107-001135 1 X
2-14 HOLDER-CCD JC61-00894A 1 X
2-15 ELA HOU-SCAN MOTOR JC96-03069A 1 O
2-15-1 BRACKET-SCAN MOTOR R2 JC61-00895A 1 X
2-15-2 MOTOR STEP-SCAN JB31-00011A 1 X
2-15-3 GEAR-REDUCTION JC66-00530A 1 X
2-15-4 GEAR-IDLE JB66-00083A 1 X
2-15-5 GEAR-TIMING JC66-00531A 1 X
2-15-6 PMO-HOLDER BELT JB72-00764A 1 X
2-15-7 RING-E 6044-000125 1 X
2-16 CBF-HARNESS-PLATEN JC39-00362A 1 X
Service Manual
8-13
Samsung Electronics
manuals4you.com
8.6 Middle Cover Assembly
5
6 4
Middle Cover Assembly Parts List


0 ELA HOU-COVER MIDDLE JC96-03247A 1 O
1 COVER-M-MIDDLE R2 JC63-00502A 1 O
2 COVER-REAR UPPER JC63-00388B 1 O
3 PMO-STACKE_RX JC72-00973A 1 O
4 BUSH-F/DOWN R2 JC61-00902A 1 X
5 CBF HARNESS-OPE JC39-00350A 1 O
6 PBA SUB-USB HOST JC92-01636A 1 O
Service Manual
8-14
Samsung Electronics
62
61
63
63-1
63-2
49
34 Transfer Roller Unit Fuser
29
56 32 38 61
Samsung Electronics
37
65-2 65-3
30 36
65
31 65-4 65-1
28 23 49
69
68
71 5
8.7 Frame Assembly
51 72 71
42 5 55 3
46 5 54
39
46-1
43
1
46-2 2
41 70
17
44 40
47 45-1
47-1 45-2
45
47-2 45-3
47-3
47-4
16
manuals4you.com
18 15 4
50 1
47-5
26
0
ELA HOU-FRAME
25 58
24 8
20
9
11
12
73 75
25
27-3
33
10
74 13
78 27-1
27 7 6
14
76 21
27-2
67 77
19-2
58
19-1
22
Service Manual
19
8-15
Frame Assembly Parts List


0 ELA HOU-FRAME 110V JC96-03186A 1 X 110V
ELA HOU-FRAME 220V JC96-03187A 1 X 220V
1 FRAME-BASE R2 JC61-00906A 1 X
2 GUIDE-P-TR JC61-00607A 1 O
3 PLATE-P-SAW JC61-00604B 1 X
4 GUIDE-M-TR RIB JC61-00594A 1 O
5 PMO-GEAR_EXIT_DRV16 JC72-00143A 3 X
6 FOOT-BACK JC61-00835A 2 X
7 FOOT-FRONT JC61-00836A 2 O
8 GROUND-GUDIE TR R2 JC63-00397A 1 X
9 MEC-TERMINAL JC75-00049A 4 O
10 PLATE-TERMINAL CON R2 JC61-00903A 3 X
11 PLATE-TERMINAL CR R2 JC61-00904A 1 X
12 HOUSING-TERMINAL R2 JC61-00911A 1 X
13 PMO-LOCKER CST JC72-00983A 2 O
14 PMO-ACTUATOR CVR OPEN JC72-00974A 1 O
15 PMO-PLATE GUIDE DEVE_R JC72-00985A 1 O
16 SPRING ETC-GUIDE DEVE JC61-70932A 2 O
17 GROUND-PUSH BUSHING JC63-00401A 1 X
18 PMO-PLATE GUIDE DEVE_L JC72-00984A 1 O
19 PMO-ACT FEED R2 JC72-01323A 1 X
20 PMO-ACTUATOR EMPTY JC72-00975A 1 O
21 PMO-ACT MANUAL R2 JC72-01324A 1 O
22 GROUND-EARTH TR R2 JC63-00395A 1 X
23 GROUND-TERMINAL TR JC63-00403A 1 X
24 ROLLER-FEED ROLLER 1 JC66-00526A 1 O
25 PMO-BUSHING FEED JC72-00382B 5 X
26 SHAFT-FEED JC66-00398A 1 O
27 MEA UNIT-PICKUP JC97-01926A 1 O
27-1 SPONGE-ROLLER PICK_UP JC72-01231A 1 O
27-2 HOUSING-PICK UP_R2 JC61-00909A 1 O
27-3 HOUSING-PICK UP2_R2 JC61-00910A 1 O
28 IPR-P-EARTH TRANSFER JC70-00307A 1 O
29 HOLDER-PTL R2 JC61-00907A 1 O
30 LENS-PTL JC67-00027A 1 O
31 PMO-BUSHING_TR(L) JC72-00102A 1 O
32 SPRING ETC-TR L HAWK JC61-00047A 1 O
33 ROLLER-FEED JC66-00598A 1 O
Service Manual
8-16
Samsung Electronics
Frame Assembly Parts List(Cont.)


34 BUSH-M-TR L JC61-00588A 1 O
36 SHAFT-FEED IDLE JC66-00527A 1 O
37 BUSH-M-FEED IDLE JC61-00585A 2 O
38 SPRING ETC-TR JC61-70958A 2 X
39 GROUND-DRIVE2 R2 JC63-00398A 1 X
40 SPRING-TS 6107-001170 1 X
41 CAM-M-PICK_UP JC66-00377A 1 O
42 GROUND-DRIVE R2 JC63-00394A 1 O
43 SOLENOID-FEED ROCKY2 JC33-00014A 1 O
44 SOLENOID-HB (MANUAL) JC33-00010A 1 O
45 MEA UNIT-GEAR PICKUP JC97-01929A 1 O
45-1 GEAR-PICK UP B_R2 JC66-00705A 1 X
45-2 GEAR-PICK UP A_R2 JC66-00704A 1 X
45-3 SPRING-CS 6107-001167 1 X
46 MEA UNIT-BRACKET FEED JC97-01925A 1 O
46-1 BRACKET-FEED R2 JC61-00913A 1 O
46-2 GEAR-Z35 IDLE JC66-00690A 1 X
47 MEA UNIT-CLUTCH JC97-01788A 1 O
47-1 GEAR-FEED 1 JC66-00393A 1 O
47-2 PMO-COLLAR_SPRING JC72-00978A 1 O
47-3 SPRING-TS 6107-001171 1 O
47-4 PMO-HUB CLUTCH JC72-00981A 1 X
47-5 SHAFT-FEED JC66-00398A 1 O
49 PLATE-PUSH BUSHING JC61-00914A 2 X
50 GEAR-FEED 2 JC66-00394A 1 O
51 GEAR-IDLE 23 JC66-00396A 1 O
52 SPRING-TS 6107-001164 1 X
53 SPRING-TS 6107-001165 1 X
54 IPR-P-TERMINAL DEVE KEY JC70-00340A 3 X
55 GROUND-TERMINAL DEVE JC63-00458A 1 X
56 PBA SUB-PTL JC92-01620A 1 O
58 HOLDER-TERMINAL R2 JC61-00908A 1 X
59 HOLDER-ACT MANUAL R2 JC61-00912A 1 X
61 HOLDER-BEARING EXIT F/DOWN JC61-00829A 2 X
62 GEAR-EXIT F/DOWN JC66-00038A 1 O
63 ROLLER-EXIT F/DOWN JC66-00378A 1 O
64 RMO-RUBBER EXIT JC73-40915A 4 O
Service Manual
8-17
Samsung Electronics
manuals4you.com
Frame Assembly Parts List(Cont.)


65 MEA RACK-EXIT ROLLER JC97-01034A 4 X
65-1 PMO-HOLDER EXIT ROLL JC72-41006A 1 X
65-2 PMO-ROLLER FD F JC72-41007A 1 X
65-3 PMO-ROLLER FD R JC72-41008A 1 X
65-4 SPRING ETC-EXIT ROLL FD JC61-70911A 1 X
66 GUIDE-SUB FRONT JC61-00917A 1 X
68 PBA-SUB-CRUM JC92-01605A 1 O
69 CBF HARNESS CRUM2 JC39-00356A 1 X
70 PBA SUB-EXIT SENSOR JC92-01604A 1 O
71 GROUND-SHIELD R2 JC63-00402A 1 X
72 LABEL(R)-HOT CAUTION,KME JC68-00317A 1 X
73 BUSH-M-PICK_UP L JC61-00586A 1 O
74 SHAFT-P-PICK_UP JC66-00399A 1 O
75 STOPPER-PICK UP_R2 JC61-00915A 2 X
76 PMO-IDLE PICK_UP JC72-00982A 2 X
77 BUSH-M-PICK_UP R JC61-00587A 1 O
78 SHAFT-CORE JC66-00720A 2 X
Service Manual
8-18
Samsung Electronics
8.8 Fuser Assembly
36 0
12 6
14
17
34
4 38
1
5
29 3
37
31
29
37
32 13
35 15
30
11
16
33
20
23 19
18
21
22 25
9 28
8 24
36
10
7
27
38
26
Service Manual
8-19
Samsung Electronics
manuals4you.com
Fuser Assembly Parts List


0 ELA HOU-FUSER 110V JC96-03210A 1 O 110V
ELA HOU-FUSER 220V JC96-03260A 1 O 220V
1 COVER-FUSER R2 JC63-00363A 1 X
2 HOLDER-PLATE CLAW R2 JC61-00886A 4 X
3 SPRING ETC-CLAW JC61-00064A 4 X
4 PMO-ROLLER_EXIT JC72-40361A 2 X
5 SPRING ETC-FUSER EXIT JC61-70976A 2 X
6 THERMOSTAT-150 JC47-00005A 1 O
7 PMO-GEAR_EXIT_DRV16 JC72-00143A 1 X
8 GEAR-IDLE 23 JC66-00396A 1 O
9 RING-E 6044-000125 1 X
10 GEAR-RDCN 25/15 JC66-00397A 1 O
11 ROLLER-HEAT_210 JC66-00729B 1 X
12 ELECTRODE-LFET R2 JC70-00473A 1 X
13 THERMISTOR-NTC 1404-001337 1 X
14 ELECTRODE-RIGHT R2 JC70-00472A 1 X
15 CBF HARNESS-FUSER 110V JC39-00353A 1 X WHITE
CBF HARNESS-FUSER 220V JC39-00354A 1 X BLACK
16 BUSH-HR R_R2 JC61-00887A 1 X
17 LABEL(P)-CAUTION, HOT_FUSER JC68-30928D 1 X
18 RMO-RUBBER_EXIT JC73-00017A 2 X
19 ROLLER-M-EXIT F/UP JC66-00380A 1 O
20 ROLLER-PRESSURE JC66-00600B 1 O
21 BEARING-PRESSURE/R JC66-10901A 2 X
22 SPRING-CS 6107-001168 2 X
23 PMO-BUSHING TX JC72-00382A 3 X
24 HOLDER-ACTUATOR JC61-00581A 1 X
25 PMO-ACTUATOR EXIT R2 JC72-01319A 1 X
26 FRAME-FUSER R2 JC61-00890A 1 X
27 GUIDE-INPUT R2 JC61-00889A 1 X
28 SPRING-TS 6107-001165 1 X
29 NUT-HEXAGON 6021-000222 5 X
30 BUSH-HR L_R2 JC61-00888A 1 X
31 PLATE-P-CLAW JC61-00605A 4 X
32 GEAR-FUSER R2 JC66-00695A 1 X
33 LAMP-HALOGEN 110V 4713-001182 1 O 110V
LAMP-HALOGEN 220V 4713-001183 1 O 220V
34 LABEL(R)-LV FUSER JC68-00408A 1 X
35 SCREW-TAPTIEE 6003-000196 1 X
36 SCREW-ASS'Y MACH 6006-001193 6 X
37 SCREW-TAPTIEE 6003-000269 6 X
38 BRUSH-ANTISTAIC JC75-00095A 1 X
Service Manual
8-20
Samsung Electronics
8.9 MP Assembly
26
11
12
28
14
2 23
14
23
25
21 1
7
25
3
30
18
9
24
31
29
16 10 20
17
13 6
15
5-1
5-3
5
27
19 5-2 4
19
Service Manual
8-21
Samsung Electronics
manuals4you.com
MP Assembly Parts List

0 ELA UNIT-MP JC96-03132B 1 O
1 FRAME-17-MP JC61-00923A 1 X
2 SOLENOID-MP JC33-00015B 1 X
3 CBF HARNESS-MPF SEN JC39-00365B 1 X
4 BUSH-M-PICK-UP R JC61-00587A 1 O
5 MEA UNIT-PICK UP JC97-02034A 1 O
5-1 HOUSING-M-PICK UP2_R2 JC61-00909A 1 O
5-2 HOUSING-M-PICK UP_MP JC61-00925A 1 X
5-3 RUBBER-PICK UP_MP JC73-00194A 1 X
6 STOPPER-M-PICK UP_R2 JC61-00915A 2 X
7 HOLDER-M-PAD_MP JC61-00924A 1 O
9 HOLDER-M-SENSOR_MP JC61-00926A 1 X
10 PLATE-P-KNOCK UP_MP JC61-00927A 1 X
11 BRACKET-P-PICK UP_MP JC61-00932A 1 X
12 GEAR-IDLE 23 JC66-00396A 1 O
14 ROLLER-M-IDLE FEED JC66-00529A 2 O
15 GEAR-M-PICK UP_MP JC66-00710A 1 X
16 GEAR-M-HOLDER_MP JC66-00709A 1 X
17 CAM-M-PICK UP_MP JC66-00711A 1 X
18 PMO-ROLLER CAM_MP JC72-00761A 1 X
19 PMO-IDLE PICK UP JC72-00982A 2 X
20 PMO-M-ACT EMPTY MP JC72-01338A 1 X
21 RPR-FRICTION PAD JC73-00140A 1 O
23 SPRING-ETC-EXIT ROLL FD JC61-70911A 2 X
24 RPR-PAD CASSETTE JC73-00141A 1 X
25 SPRING-ES 6107-001237 2 X
26 SHEET GUIDE PAPER R2 JC63-00545A 1 X
27 SHAFT-P-CORE JC66-00720A 2 X
28 SHEET GUIDE MP JC63-00448A 1 X
29 SPRING-CS 6107-001167 1 X
30 SPRING-ES 6107-001047 1 X
31 PHOTO INTERRUPTER 0604-001095 1 O
Service Manual
8-22
Samsung Electronics
8.10 Cassette Assembly
12
14 13
16
4
6-4
6-3
6-2
6-1 15
5
3
7
5
10
11
1
17
Service Manual
8-23
Samsung Electronics
manuals4you.com
Cassette Assembly Parts List


0 MEA-CASSETTE JC97-02020A 1 O
1 FRAME-M-CASSETTE JC61-00876D 1 O
2 GUIDE-M-EXTENSION LARGE JC61-00918B 1 X
3 PMO-EXTENSION SMALL JC72-00971A 1 O
4 PLATE-P-KNOCK_UP JC61-00603A 1 X
5 SPRING-CS 6107-001166 2 X
6 MEA UNIT-HOLDER PAD JC97-01931A 1 O
6-1 HOLDER-M-PAD JC61-00580A 1 O
6-2 SHEET-HOLDER PAD R2 JC63-00407A 1 X
6-3 RPR-FRICTION PAD JC73-00140A 1 O
6-4 IPR-PLATE PAD JC70-00314A 1 O
7 SPRING ETC-EXIT ROLL FD JC61-70911A 1 X
8 COVER-M-SUB CASSETTE R2 JC63-00490A 1 X
10 PMO-PLATE_LOCKER JC72-00972A 1 O
11 SPRING ETC-LOCKER,PLATE JG61-70531A 1 O
12 ADJUST-M-CASSETTE_L JC70-00300A 1 O
13 ADJUST-M-CASSETTE_R JC70-00301A 1 O
14 GEAR-PINION JG66-40003A 1 O
15 RPR-PAD CASSETTE JC73-00141A 1 X
16 CAM-KNOCK UP JC66-00719A 1 X
17 INDICATOR-CST PAPER JC64-00143A 1 X
Service Manual
8-24
Samsung Electronics
0
Samsung Electronics
2
28 4
39
38
39-2 30
39-5
25
39-10
39-4 19
39-1 18
39-7 39-9 17 32 26
39-3
39-6 22 27
23 33
39-8 37
20 41
21
28
24
34
manuals4you.com
29
5
40
3
1-4
1-3
1 31 35
11 10
6
13
8.11 SCF(Option Cassette Frame) Exploded view
42 14
9
15 34
8
7
16 12 36
Service Manual
8-25
SCF(Option Cassette Frame) Assembly Parts List


0 ELA UNIT-SCF R2 JC96-03132B 1 O
1 COVER-M-FRONT SCF R2 JC63-00505A 1 O
2 COVER-M-SIDE L SCF JC63-00500A 1 X
3 COVER-M-SIDE R SCF JC63-00499A 1 O
4 COVER-M-REAR SCF R2 JC63-00503A 1 O
5 FRAME-M_SCF JC61-00877A 1 X
6 HOUSING-M-PICKUP_R2 JC61-00909A 1 O
7 HOUSING-M-PICKUP2_R2 JC61-00910A 1 O
8 SPONGE -ROLLER PICK_UP JC72-01231A 1 O
9 SHAFT-P-CORE JC66-00720A 2 X
10 PMO-BUSHING FEED JC72-00382B 2 O
11 BUSH-M-PICK_UP L JC61-00586A 1 O
12 BUSH-M-PICK_UP R JC61-00587A 1 O
14 PMO-IDLE PICK_UP JC72-00982A 2 X
15 ROLLER -FEED JC66-00598A 1 O
16 PMO-BUSHING TX JC72-00382B 2 O
17 PMO-GEAR PICK_UP A JC72-00979A 1 X
18 PMO-GEAR PICK_UP B JC72-00980A 1 X
19 SPRING-CS 6107-001167 1 X
20 RING-CS 6044-000001 1 X
21 CAM-M-PICK_UP JC66-00377A 1 O
22 SHAFT-FEED JC66-00527A 1 O
23 GEAR -FEED 2 JC66-00394A 1 O
24 SPRING-TS 6107-001170 1 X
25 PCB-SENSOR JC41-00247A 1 X
26 PBASUB-SCF JC92-01614A 1 O
27 CBF HARNESS -SCF GND JC39-00366A 1 X
28 CBF HARNESS -SCF JC39-00357A 1 X
29 COVER-M-SIMM R2 JC63-00492A 1 X
30 SHEET-COVER SENSOR JC63-00369A 1 X
31 PMO-ACTUATOR EMPTY JC72-00975A 1 O
32 IPR-GND TOP JC70-11028A 1 X
33 SOLENOID-HB(MANUAL) JC33-00010A 1 X
34 PMO-LOCKER CST JC72-00983A 1 O
35 FOOT-BACK JC61-00835A 1 O
36 FOOT-FRONT JC61-00836A 2 O
37 SCREW-ASS’Y TAPT 6006-001078 1 X
Service Manual
8-26
Samsung Electronics
SCF(Option Cassette Frame) Assembly Parts List


38 SCREW-TAPTITE 6003-000196 10 X
39 ELA HOU-MOTOR SCF JC96-03003A 1 O
39-1 BRKT-P-MOTOR SCF JC61-00879A 1 X
39-2 BRKT-P-GEAR SCF JC61-00881A 1 X
39-3 BRKT-M-FEED SCF JC61-00878A 1 X
39-4 GEAR 61/47 IDLE JC66-00688A 1 X
39-5 GEAR 59 IDLE JC66-00689A 1 X
39-6 GEAR 35 IDLE JC66-00690A 1 X
39-7 GEAR-RDCN 57/18 JC66-00389A 1 X
39-8 GEAR-IDLE 23 JC66-00396A 1 X
39-9 MOTOR STEP(SCF) JC31-00009A 1 O
39-10 SCREW-MACHINE 6001-000131 5 X
39-11 CORE-FERRITE 3301-001635 1 X
39-12 CABLE TIE 6501-000004 1 x
40 BUSH CABLE JC61-00804A 1 X
41 SCREW-TAPTITE 6003-000196 1 X
42 MEC-CASSETTE JC97-02020A 1 X
Service Manual
8-27
Samsung Electronics
manuals4you.com
MEMO
Service Manual
8-28
Samsung Electronics
Appendix (Parts code)
Update: 9/10/04
NO. Buyer-Model Code ELA HOU-SCAN ELA HOU-OPE PBA SUB-LIU
SCX-4720F/XAA JC96-03184A JC96-03174A JC92-01599A

1
SCX-4520/XAA JC96-03181A JC96-03183A
SCX-4720F/XEC JC96-03184B JC96-03174B JC92-01599B
2
SCX-4520/XEC JC96-03181B JC96-03183B
SCX-4720F/XEF JC96-03184C JC96-03174C JC92-01599B
3
SCX-4520/XEF JC96-03181C JC96-03183C
SCX-4720F/XEG JC96-03184D JC96-03174D JC92-01599B
4
SCX-4520/XEG JC96-03181D JC96-03183D
SCX-4720F/XEP JC96-03184J JC96-03174J JC92-01599B
5
SCX-4520/XEP JC96-03181J JC96-03183J
SCX-4720F/XET JC96-03184E JC96-03174E JC92-01599B
6
SCX-4520/XET JC96-03181E JC96-03183E
SCX-4720F/XEU JC96-03184A JC96-03174A JC92-01599B
7
SCX-4520/XEU JC96-03181A JC96-03183A
SCX-4720F/XIL JC96-03184F JC96-03174F JC92-01599A
8
SCX-4520/XIL JC96-03181F JC96-03183F
SCX-4720F/XSG - -
9 -
SCX-4520/XSG JC96-03181A JC96-03183A
SCX-4720F/XEV JC96-03184G JC96-03174G JC92-01599A
10
SCX-4520/XEV JC96-03181G JC96-03183G
SCX-4720F/XSA
11 - - -
SCX-4520/XSA
12 SCX-4720F/XIP JC96-03184A JC96-03174A JC92-01599A
manuals4you.com
MAIN
9
AC 110V / 220V
Samsung Electronics
NETWORK SMPS PAPER EMPTY MHV
SENSOR
INLET & SUPPLY
Reset BootROM (2MBx2ea)
IEEE1284 SPGPm POWER S/W EXIT SENSOR
26P DEV
SDRAM(32MB)
ARM946ES + 5V MP EMPTY
USB 2.0 USB Driver THV
DRAM Backup logic + 12V SENSOR
CACHE(16K*2)
NET2272 + 24V OPC GND
SDRAM Control PCL6(2MB x 2ea) FEED SENSOR
+ 24VS
MAIN MOTOR ROM Control HVPS
PS3(2MB x 2ea) AC PWR
9. Block Diagram
MAIN MOTOR COVER S/W

DRIVER DMA Control
A3977SLR MEMORY DIMM
PVC 2P 2P
ADF UNIT GEU/HCT/gCODEC 2P
FUSER FAN
P-REGI, P-DET, P-POS I/O I/F THERM.
SENSOR MODEM
EngineControl
ADF MOTOR DRIVER FM336
IEEE1284/USB2.0 33.6KBPS AUDIO Drv. 2P
TEA3718X 2EA
3P LINE
LIU
FAST SRAM EXT. PHONE
(128 KByte) CIP4
LCD, 16*2 LINES
14P ImageProcesser NETWORK INTERFACE CARD
OPE
AFE I/F SCF(Option)
¡ MICOM
¡ LCD/LED Drive I/O PORT
¡ Key Scan CIP4 AFE
MotorControl
4P
CARTRIDGE INFO.
11P
3P CCD DRIVING LSU
FLAT COVER SENSOR DMA Control
PART 4P
MP CLUTCH
RTC 3P
MAIN CLUTCH
600 DPI, COLOR CCD FLATEN MOTOR 2P
JPEG Codec
DRIVER PTL
TEA3718X 2EA 5P
USB Host
FLATEN MOTOR
Service Manual
Block Diagram
9-1
Connection Diagram
10
10. Connection Diagram
CN2
CN23
CN1
CN3
CN18
CN25
CN15
CN21
CN24
CN11
CN9
CN7
CN8
CN17
CN20
CN5
CN2
CN4
CN1
CN9
Service Manual
10-1
Samsung Electronics
manuals4you.com
Schematic Diagram
11. Schematic Diagrams

11.1 Main Board(1/16)
Service Manual
11-1
Samsung Electronics
This Document can not be used without Samsung’s authorization.
Main Board(2/16) Schematic Diagram
Service Manual
11-2
Samsung Electronics
manuals4you.com
Service Manual
11-3
Samsung Electronics
Service Manual
11-4
Samsung Electronics
manuals4you.com
Service Manual
11-5
Samsung Electronics
Service Manual
11-6
Samsung Electronics
manuals4you.com
Service Manual
11-7
Samsung Electronics
Service Manual
11-8
Samsung Electronics
manuals4you.com
Service Manual
11-9
Samsung Electronics
Service Manual
11-10
Samsung Electronics
manuals4you.com
Service Manual
11-11
Samsung Electronics
Service Manual
11-12
Samsung Electronics
manuals4you.com
Service Manual
11-13
Samsung Electronics
Service Manual
11-14
Samsung Electronics
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manuals4you.com
Service Manual
11-15
Samsung Electronics
Service Manual
11-16
Samsung Electronics
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Schematic Diagram
11.2 LIU Board
Service Manual
11-17
Samsung Electronics
Schematic Diagram
11.3 OPE Board
Service Manual
11-18
Samsung Electronics
manuals4you.com
Schematic Diagram
11.4 USB Host Board
Service Manual
11-19
Samsung Electronics
Schematic Diagram
11.5 SMPS_110V
Service Manual
11-20
Samsung Electronics
manuals4you.com
Schematic Diagram
11.6 SMPS_220V
C101
AR1 C3 C2 1KV2 22
DSS-601M 472MAA* 2
F1 LF1 F2 LF2 B101
TH1
250V8A SW0610V 250V3.15A CH925130
8D-15 1/2W3.3K * 10 CON2-16
INL ET 24V(0.7A)
R117
SW1 D101
BD1 R5 50m
3024-P3T4DBKBKR 2 200V10A
D3SBA60 3W47K
6 SW2
1/4W 330K* 2
C6 7 CON2-11,12,1 3
R113
R102
R103
R104
R105
R106
R107
R129
R130
R131
1KV223 24VS(2.5A)
TNR1 C1
R14 R118
10D561K 474 R1 C4 R2 C102 SS-5GL
1/4W 82K* 2
50m
1/2W 474 C5 9 WB
560K 400V 5 35V1000uF
220uF
INL ET R15
30* 30
SW1/B C105
50V1uF
D5 C9 1
UF4007 1KV221
CON2-9,10,18
R3
GND
L1
AY70 C106
C7
1K471
35V47uF
F101
D6 R6
R11 250V2A CON2-3,4
C10 200V1A 1/4W22
1W47 5V(1.5A)
630V333 R8
FUSIBLE ZD4 D7 B1 D102 L101
12K
18V 1N4148 5uH
R110
1K
CON1 Q2
D103
SPA07N60C3
R10 R16 40V3A* 2 R111
U1
22 220 R109 2.7KF
ICE2BS01
VC C 6
GA T E 5
2 SOFT -ST A RT
N.C
10
Q1 3 C107 PC101
BTA12-600B WB 817M-B
I- SENSOR 4 10V1500uF C108 C109 R108
R13 C11 R17 50V1uF 10V470uF 1W150J
7 GND
12
1/4W22 50V104 3 F/B 220 4
R12 R7
PC102 1W180 200 U101 R112
TLP3061F FUSIBL E TL 431 2.6KF
C15
R9
222
W.W 1N0.47
C8 C14
105 333
PC101
R114
817M-B
1/2W1.5K CON2-5,6,7
GND
PT1
C13 EER3435V
472MAA
24VS
C12
472MAA
FUSER-ON
Q102
C1008-Y
CON2-1 FEED-SEN
5V 5V CON2-2 PAPER-EMPT
R125 R127 +24VS CON3 5V
ZD3 ZD2 ZD1
1/4W 150MI NI
1/4W150 1/4W150 GND1 CON2-17 THV-PWM
CON3-3
CON2-14 MANUAL
GND2
R132
R115 R116 D105 200V 200V 200V
R126 R128 CON3-2 CON2-15 THV-READ
1/4W150 47K 1N4003 R133
47K 47K
MA NUAL 47K CON2-20 THV-EA
PAPER EMPTY CON3-1
CON2-14
CON2-2 R119 CON2-19 BIAS-PWM
FAN 2.2K CON4
CON2-1 Q101 CON2-22 MH V-PWM
CON2-23
FEED SENSOR KSC1008-Y TNR101
3 CON2-21 N.C
EXI T
OP104 OP103 OP102 OPC1
CON2-23 FAN
2G-288 KPI -512 KPI -512 R120 2 CON2-24
7D561
5.6K CON2-24 EXI T
1
D GND CON2-25 N.C
CON2-26 FUESR-ON
Service Manual
11-21
Samsung Electronics
Schematic Diagram
11.7 HVPS
5V 24V
5V
C115 R209
104 100K
IT201
R202
THV PWM 100
CN2-#17 4
9 8 Q201 R210 C206 C210
THV 5.6KJ 6KV221
A708-Y MY-2A104 2 C211
R201 D201
6KV221
430 1N4148 U102/B
11
5 6 D205 D206
KA324 Q202 D204 6KV 6KV
THV-sen >> 945C-Y
5 +
1 7
7
6 - 6KV C209
R208
R204 R205
4
10K
22K >> THV
47K
R203 THV 6KV221
R212
2KJ 100K Q203 RDS1/2W100KJ
C201 C202 C208
C2383 D203
MY2A473 102 MY-2A681
C203 R207 D1NL20U
C205 VA201
681 330KJ 7N221K
MY- 2A471
C212
D202 2KV221
VA202
D1NL20U R213
ZD201 7N431K
BLR1/2W100MF
2.7VB
VA203
7N561K
R206
R211 24V
130KF
1/4W4.7J
R302 D C302
5V
470K CE-103
IT301
R301 4
5.6K R303 D302
THV -EA C301
Q301 470J 4KV
CN1-#20 MY2A104J 2 R305
945C-Y C304
3 4 BLR1/2W50MJ
THV 3KV151
C303 5 6
103
1 7
>>THV-sen
C306 Q302 R306
MY2A473J +5V C2383 100KF
D303
D301 1N4148
ZD301 D1NL20U
INDEX R309 +5V 2.7VB
50K 3KF R304
R307 1/4W4.7 D304 C305
THV REA 150KF D305 104
1N4148
CN2-15 3 1N4148
+
1
THV_READ
R308 - 2
1KF
ZD302
C307 IC105/A
2.7VB
MY2A473J
R310
200J
Service Manual
11-22
Samsung Electronics
manuals4you.com
Appendix (Parts code)
Update: 9/10/04
NO. Buyer-Model Code ELA HOU-SCAN ELA HOU-OPE PBA SUB-LIU
SCX-4720F/XAA JC96-03184A JC96-03174A JC92-01599A

1
SCX-4520/XAA JC96-03181A JC96-03183A
SCX-4720F/XEC JC96-03184B JC96-03174B JC92-01599B
2
SCX-4520/XEC JC96-03181B JC96-03183B
SCX-4720F/XEF JC96-03184C JC96-03174C JC92-01599B
3
SCX-4520/XEF JC96-03181C JC96-03183C
SCX-4720F/XEG JC96-03184D JC96-03174D JC92-01599B
4
SCX-4520/XEG JC96-03181D JC96-03183D
SCX-4720F/XEP JC96-03184J JC96-03174J JC92-01599B
5
SCX-4520/XEP JC96-03181J JC96-03183J
SCX-4720F/XET JC96-03184E JC96-03174E JC92-01599B
6
SCX-4520/XET JC96-03181E JC96-03183E
SCX-4720F/XEU JC96-03184A JC96-03174A JC92-01599B
7
SCX-4520/XEU JC96-03181A JC96-03183A
SCX-4720F/XIL JC96-03184F JC96-03174F JC92-01599A
8
SCX-4520/XIL JC96-03181F JC96-03183F
SCX-4720F/XSG - -
9 -
SCX-4520/XSG JC96-03181A JC96-03183A
SCX-4720F/XEV JC96-03184G JC96-03174G JC92-01599A
10
SCX-4520/XEV JC96-03181G JC96-03183G
SCX-4720F/XSA
11 - - -
SCX-4520/XSA
12 SCX-4720F/XIP JC96-03184A JC96-03174A JC92-01599A

Samsung Digital Laser MFP SCX 4720F Series SCX 4720 SCX 4520 Parts Service Manual

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DIGITAL LASER MFP

DIGITAL LASER MFP CONTENTS

1.1 Safety Warning

(2) Use only Samsung replacement parts

(3) Laser Safety Statement

CAUTION - INVISIBLE LASER RADIATION

1.2 Caution for safety

1.2.1 Toxic material

1.2.2 Electric Shock and Fire Safety Precautions

1.2.3 Handling Precautions

1.2.4 Assembly / Disassembly Precautions

1.2.5 Disregarding this warning may cause bodily injury

(1) Be careful with the high temperature part.

(4) Ensure the printer is installed safely.

1.3 ESD Precautions

1.4 Super Capacitor or Lithium Battery Precautions

2.1 Tool for Troubleshooting

• DVM (Digital Volt Meter) • Cleaning Equipments

2.2 Acronyms and Abbreviations

AC Alternating Current IC integrated circuit

2.3 The Sample Pattern for the Test

2.3.3 A4 IDC 5% Patten

2.3.4 A4 ISO 19752 Standard Pattern

2.4 Wireless LAN

Division Basic type Recommend type

CPU Over PENTIUM 233M PENTIUM 300MHz

• About the certificated mark of Wi-FiTM

- The Wi-FiTM is a registered trademark of WECA (Wireless Ethernet

3.1 General Specifications

Items SCX-4520 SCX-4720F

3.2 Print Specification

3.3 Scan Specification

3.4 Copy Specification

COPY Copy Quality Text 600x300dpi

Items SCX-4520 SCX-4720F

3.5 Fax Specification

Fax Compatibility No ITU-T G3

3.6 Other Specification

Network Option Yes (Standard)

Items SCX-4520 SCX-4720F

Software Compatibility DOS No

4.1 Printer Components

4.1.2 Rear View

4.1.3 Control Panel (SCX-4720F)

Control Panel (SCX-4520)

Adjusts the brightness of the documents for

Uses to scroll through the available options for

Confirms the selection on the display.

Sends you back to the upper menu level.

Stops an operation at any time.

Selects the number of copies.

Allows you to use special copy features, such

Makes a copy smaller or larger than the original.

Allows you to save on toner by using less

Allows you to directly print files stored on a USB

4.2 System Layout

4.2.1 Feeding section

- Feeding Method: Universal Cassette Type