Chapter 1

Computer Maintenance and Technical Support

Content
Bus
Types of Bus
Cards
The Video Card
The Sound Card
Network card
I/O Connectors
The Serial Port
The Parallel Port
I/O connectors
Monitor
Introduction to Monitor
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 Types of Displays
Health and Safety Concerns
 Monitor Connections

 Troubleshooting the Video System

 BIOS

 Basic Input/Output System

 Error messages and solutions

 Advanced BIOS Features

 Printers

 Printer Types and Printer Technology

 Printer Field Replaceable Units•

 Printer Maintenance Techniques

 A bus is a pathway on the motherboard that enables the components to

communicate with the CPU.

 All motherboards have one or more system I/O buses that are used to
expand the computer’s capabilities.

 Expansion slots

 It is an expansion bus slot used to attach adapter cards to the

motherboard.

 Three main types of expansion standards:

 ISA, PCI, AGP

ISA - Industry Standard Architecture

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  ISA slots are black in color, long, slow speed and old type architecture.

 8-bit and 16-bit wide lSA are common types of architecture.

PCl - Peripheral Component Interconnect

 PCI slots are white in color, short, faster than lSA and modern type
architecture. 32-bit [old type] and 64 bit wide PCl are common types of
architecture.

 These days, every card plugs on PCl slots.

AGP - Acce1erated Graphics Port

 AGP slots are brown in color, very short, faster speed and it is only
designed for modern graphic [video] cards.

64-bit wide is a common AGP slot

Video card

 a display adapter used to connect the motherboard to the monitor. You

can't see any picture without the video card.

Troubleshooting Tips for a VGA problem

 No display on the monitor

 Unending string of beeps….

 Display message ― “no power to video card adapter”

 System freezes up during POST

 Incompatibility

Video card (Solution for a VGA)

 Check the monitor power comes on.

 Check the outlet.

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  Check the monitor cable and the power cord is fully in the socket.

 Check for missing pin

 Check the problem by elimination technique

Swap and check the functionality of data, video cables and the VGA step by
step.

Problem

 Modem cannot dial and "no Dial tone" message appears on the monitor

Solution

 Check the phone card connection.

 Make sure the jack on the modem labeled "line" is connected to phone
line wall jack.

Problem

 The modem disconnects while on line.

 This may be caused by line interference. Retry the connection by dialing the
numbers again.

MONITOR.

 Monitor is an output device that receives video signals from computer and
displays the information for the user.

 Monitor resolution is the number of horizontal pixels times the number of

vertical pixels.

 640 x 480 indicates - horizontal resolution 640 pixels and vertical

resolution 480 pixels. 640 x 480 = 307,200 pixels.

 Lower resolution means fewer (larger pixels) on screen

 higher resolution means more (smaller pixels) on screen

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 Some common resolutions are 640 x 480,800 x 600, 1,024 x 768, 1,280 x
1,024, and 1,600 x 1,200.

 There are two main types of monitors:

 CRTs: have a large part at the back and common on desktop computers.

 LCDs: are flat screens and commonly used on laptops and desktop.

 Monitors differ in several ways such as the resolution and the number of
colors it can produce.

 Resolution refers to how clear the image on the monitor is.

 Pixels are individual dots used to display an image on a computer

monitor. The more pixels a screen can show, the higher the quality.

Chapter 2
NETWORK

A network consists of two or more computers that are linked in order

to share resources (such as printers and CDs), exchange files, or
allow electronic communications. The computers on a network may
be linked through cables, telephone lines, radio waves, satellites, or
infrared light beams.

What is network definition and types?

A computer network is a group of computers linked to each other that

enables the computer to communicate with another computer and share
their resources, data, and applications. A computer network can be
categorized by their size. A computer network is mainly of four types:
LAN(Local Area Network)
What are the 4 types of network?

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 PAN (Personal Area Network)
 LAN (Local Area Network)
 MAN (Metropolitan Area Network)
 WAN (Wide Area Network)
What are the 5 types of network?
 Local Area Network (LAN)
 Wireless Local Area Network (WLAN)
 Wide Area Network (WAN)
 Virtual Private Network (VPN)
 Virtual Local Network (VLAN)
There are two main types of network :
 a local area network (LAN)
 a wide area network (WAN)
 What are components of network?


 Computer network components are the major parts which are needed to install
the software. Some important network components are NIC, switch, cable, hub,
router, and modem. Depending on the type of network that we need to install,
some network components can also be removed.
 What is network advantages and disadvantages?


 The advantages of computer networks include resource sharing, improved

communication, and increased productivity. Disadvantages include
security risks, dependence on technology, and potential for network failures.30 ጁን
2023

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What is LAN man and WAN?
LAN is a network that usually connects a small group of computers in a given
geographical area. MAN is a comparatively wider network that covers large regions- like
towns, cities, etc. The WAN network spans to an even larger locality. It has the capacity
to connect various countries together.

Difference Between LAN, MAN, and WAN

A network allows various computers to communicate with other computers by connecting via a
medium. There are three major types of a computer network-namely WAN, MAN, and LAN-
designed for operating in an area that they cover. In this article, we will discuss the primary
difference between LAN, MAN, and WAN. But before we do that, we will look into each of
them individually.

All three of these are similar yet different in various aspects- the significant difference
being their geographical locations coverage. WAN covers the largest area, MAN
comprises more area than LAN, and LAN only covers a small area.

Various other types of computer networks also exist, such as:

 Virtual Private Network (VPN)

 Enterprise Private Network (EPN)
 Storage Area Network (SAN)
 Personal Area Network (PAN)

What is LAN?
It is an abbreviation for Local Area Network. It connects various network devices in a
way that the workstations and PCs (personal computers) can share programs, tools,
and data. A single switch or stack of various switches connects a group of various
devices and computers together. They use a private addressing scheme- that the
TCP/IP protocol defines. The private addresses of every computer are unique in relation
to one another. At every LAN’s boundary, you will find routers that connect them all to a
larger WAN.

The rate of data transmission is very high because it links to a very limited number of
computers. These connections exhibit a higher speed and require relatively inexpensive
hardware (for example, network adapters, hubs, Ethernet cables, etc.). A LAN covers a
very small area of about a few kilometers, and people own them privately for home,

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office buildings, schools, hospitals, etc. It is very easy for people to design a LAN and
maintain it. The communication medium that it uses has coaxial cables and twisted-pair
cables. It also has minimal noise and error due to its short distance coverage.

Data rates in early LAN ranged from 4 Mbps to 16 Mbps. This speed extends to approx
100-1000 Mbps today. The LAN has a very short propagation delay. It relies typically on
wired connections (to attain better security and speed), but it may also comprise
wireless connections. The smallest of LANs may make use of just two computers, and
the larger ones may accommodate thousands of them. Users experience high fault
tolerance and low congestion in a LAN network (like a few students playing together in
the same room).

What is MAN?
It is an abbreviation for Metropolitan Area Network. It covers a smaller area than that of
WAN and a larger area as compared to a LAN. A MAN basically connects two devices
(or more) that reside apart but in the same or different cities. It may also serve as an
Internet Service Provider (ISP), and it basically covers a larger geographical area.
Customers who need a better speed and higher-quality connectivity opt for MAN. They
are very hard to maintain and design, and their speeds range in terms of Megabytes Per
Second (Mbps).

MAN shows lesser fault tolerance and more congestion in the network. It also exhibits a
moderate rate of data transfer and propagation delay. A single organization may or may
not own a MAN, as it is very costly. It makes use of devices like Cable/Wire and Modem
for data transmission. A significant example of a MAN is those telephone company
networks that are capable of providing high-speed lines (DSL) to a cable TV network or
customers in any given city.

What is WAN?
It stands for Wide Area Network. It basically extends over large areas, but it might stay
confined within a state or a country’s boundaries. A connection of various LANs may
also constitute a WAN. They may connect to each other using radio waves and
telephone lines. A WAN typically may stay limited to any enterprise (an organization or
a corporation) or may even be accessible to the general public. It comes with a
technology that is very expensive and relatively high-speed.

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WANs are basically of two types: Point-to-Point WAN and Switched WAN. It is also very
difficult to maintain as well as design a WAN. The fault tolerance is also very less, just
like MAN, and it brings more congestion in a network. The communication medium
deployed for WAN is the Satellite Link or Public Switched Telephone Network (PSTN).
The usual long-distance transmission leads to a higher error and voice in a WAN.

The data rate concerning a WAN is comparatively slower than LAN- about a tenth of its
speed. It is because of the higher distance that it covers and more number of terminals,
servers, etc. The speed of transmission may range in a WAN from a few Kbps (Kilobits
per second) to Mbps (Megabits per second). One of the biggest issues that WAN faces
is the propagation delay. A few devices that help in data transmission via WAN are:
Satellites, Microwaves, and Optic wires. One example of a Point-to-Point WAN is the
dial-up line connecting any home computer to the Internet. One example of a Switched
WAN is the ATM (Asynchronous Transfer Mode) Network.

Difference Between LAN, MAN, and WAN

Parameter LAN MAN WAN

Full Form LAN is an acronym for Local MAN is an acronym for WAN is an acronym for Wide
Area Network. Metropolitan Area Area Network.
Network.

Definition and LAN is a network that MAN is a comparatively The WAN network spans to
Meaning usually connects a small wider network that covers an even larger locality. It has
group of computers in a large regions- like towns, the capacity to connect
given geographical area. cities, etc. various countries together.
For example, the Internet is a
WAN.

Network The LAN is private. The MAN can be both The WAN can also be both
Ownership Hospitals, homes, schools, private or public. Many private or public.
offices, etc., may own it. organizations and
telecom operators may
own them.

Maintenance and Very easy to design and Comparatively difficult to Very difficult to design and

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 Designing maintain. design and maintain. maintain.

Speed LAN offers a very high MAN offers a moderate WAN offers a low Internet
Internet speed. Internet speed. speed.

Delay in It faces a very short It faces a moderate It faces a high propagation

Propagation propagation delay. propagation delay. delay.

Faulty Tolerance The LAN exhibits a better The MAN exhibits a The WAN also exhibits a
fault tolerance than the rest lesser fault tolerance. lesser fault tolerance.
of the networks.

Congestion The congestion in the It exhibits a higher It exhibits a higher congestion

network is very low. network congestion. in the network.

Communication LAN typically allows a single MAN allows multiple A huge group of computers
Allotment pair of devices to establish computers to interact can easily interact with each
a communication. But it may simultaneously with each other using the WAN.
also support more other.
computers.

Uses Schools, homes, colleges, It basically covers a city, It covers an entire country, a
hospitals, offices, etc., can a small town, or any subcontinent, or an equivalent
privately use it. given area with a bigger area.
radius than the LAN.

What are 3 basic components of network?

Routers, switches, and firewalls are three core components of any network. Once you
have an understanding of them, everything else is a little easier to understand. As the
world becomes increasingly remote, the demand for network professionals is
skyrocketing
What is the difference between TCP and IP?

TCP and IP are two separate computer network protocols. IP is the part that obtains
the address to which data is sent. TCP is responsible for data delivery once that IP
address has been found.

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 What are the 8 components of a network?

Computer network components consist of both physical parts as well as software in

order to install computer networks. The hardware components include a server, client,
hub, switch, bridge, peer, and connecting devices. Software components include the
protocols and the Operating System (OS).
What are 3 disadvantages of a network?

Disadvantages of computer networks

 Lack of robustness.
 Spread of computer virus.
 Implementation issues.
 Lack of productivity.
 Health issues.

 Types of Internet Protocol

TCP/IP(Transmission Control Protocol/ Internet Protocol) SMTP(Simple Mail Transfer Protocol)
PPP(Point-to-Point Protocol) FTP (File Transfer Protocol) SFTP(Secure File Transfer Protocol)

What are the types of protocol?

These are mentioned below:
 TCP/IP(Transmission Control Protocol/ Internet Protocol)
 SMTP(Simple Mail Transfer Protocol)
 PPP(Point-to-Point Protocol)
 FTP (File Transfer Protocol)
 SFTP(Secure File Transfer Protocol)
 HTTP(Hyper Text Transfer Protocol)

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 HTTPS(HyperText Transfer Protocol Secure)
 TELNET(Terminal Network)
 What are the functions of protocol?
 A protocol defines how the data is encapsulated in the frame or packet. Each
packet in all PDUs contains three fields for control information along with the data
field. There are three control information fields such as Address, Error
Control and Protocol Control.
What is protocol and examples?
 Protocols: It is a set of rules that need to be followed by the communicating
parties in order to have successful and reliable data communication. For example
- Ethernet and HTTP.
What are the Level 5 protocols?
 9P Distributed file system protocol developed originally as part of Plan 9.
 ADSP AppleTalk Data Stream Protocol.
 ASP AppleTalk Session Protocol.
 H.245 Call Control Protocol for Multimedia Communications.
 iSNS Internet Storage Name Service.

 What are the four Layer 2 protocols?

 Multiprotocol Label Switching (MPLS) Nortel Discovery Protocol (NDP) Serial Line
Internet Protocol (SLIP) (obsolete) Spanning tree protocol.

Chapter3
Network topology
 A network topology is the physical and logical arrangement of
nodes and connections in a network. Nodes usually include
devices such as switches, routers and software with switch and
router features. Network topologies are often represented as a
graph.
 What is the network topology and types?

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 

 There are six types of network topology which are Bus Topology, Ring Topology,
Tree Topology, Star Topology, Mesh Topology, and Hybrid Topology.
What are the three main topologies?
Which network topology is the most common?
 Star topology is by far the most common. ...
 Bus topology—also known as line or backbone—connects all devices via a single
cable running in one direction. ...
 Ring topology, as its name suggests, features all nodes arranged in a ring.

What Does Star Topology Mean? Star topology is a

network topology in which each network component is physically
connected to a central node such as a router, hub or switch. In a
star topology, the central hub acts like a server and the
connecting nodes act like clients.
Advantages of Star Topology
It is very reliable – if one cable or device fails then all the others will still work. It is high-
performing as no data collisions can occur. Less expensive because each device only
need one I/O port and wishes to be connected with hub with one link. Easier to put in.
Robust in nature.

Disadvantages of Star Topology

Highly dependent on the central device: If the hub goes down, everything goes down as
none of the devices can work without a hub. The drawback is if the central device fails, the
whole network goes down

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A bus network is a local area network (LAN) topology in which each
node -- a workstation or other device -- is connected to a main cable
or link called a bus. All connected stations on the bus can
communicate with all others on the singular network segment. A bus
network topology is simple and reliable.

What is bus topology and its advantages?

Having nodes arranged in a bus network topology brings some benefits: it is easy to
implement and to add more nodes to the network. it is quick to set up. it uses less
cabling than some other network topologies and is therefore cost effective.
What is bus topology disadvantages?
Bus topology is not great for large networks. Identification of problems becomes difficult
if the whole network goes down. Troubleshooting individual device issues is very hard.
Need terminators are required at both ends of the main cable.
A ring topology is a network design where connected devices form
a circular data channel. Each networked device is linked to two more
ones by two points on a circle. A ring network is a collective term for
the devices arranged in a ring topology.
What is ring topology advantages and disadvantages?
A Comparison Table for Advantages and Disadvantages of Ring Topology

Advantages Disadvantages

1. Fast Execution 1. Quite Expensive

2. Better Administration 2. Slow Activity Rate

3. Straightforward adaptability 3. Unprotected use

4. Need for Hardiness

4. Fidelity of network

In a Ring topology, each device is connected to specifically two

branches connected to devices. In tree topology, the devices are
organized in the form of a tree. 2. Ring topology is less reliable than
tree topology. Tree topology is more reliable as a failure of one device
does not disturb the full network.

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 A Comparison Table for Advantages and Disadvantages of Ring Topology

Advantages Disadvantages

1. Fast Execution 1. Quite Expensive

2. Better Administration 2. Slow Activity Rate

3. Straightforward adaptability 3. Unprotected use

4. Fidelity of network 4. Need for Hardiness

What are the two main types of topology?

There are two types of network topology: physical and logical. Physical
topology describes how network devices (called computers, stations, or nodes) are
physically connected in a computer network.
The 4 Different Types of Computer Network Topologies
 Bus Topology. Bus topologies have the simplest layout. ...
 Star Topology. In star topology, you use a central hub or switch as a sort of middleman
for data transmission. ...
 Ring Topology. ...
 Mesh Topology.

 A database is an organized collection of

structured information, or data, typically

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 stored electronically in a computer
system.
How Many Types of Databases Are There?
 Hierarchical Databases. Developed in the 1960s, the hierarchical database looks similar
to a family tree. ...
 Relational Databases. Relational databases are a system designed in the 1970s. ...
 Non-Relational Databases. ...
 Object oriented databases.


What is database give example?
Databases often store information about people, such as customers or users. For
example, social media platforms use databases to store user information, such as
names, email addresses and user behavior. The data is used to recommend content to
users and improve the user experience.

What are the 4 functions of database?

A database management system is a software tool that makes it possible to organize

data in a database. It is often referred to by its acronym, DBMS. The functions of a
DBMS include concurrency, security, backup and recovery, integrity and data
descriptions.

A worksheet (also known as a spreadsheet) consists of cells in which

you can enter and calculate data. The cells are organized into
columns and rows. A worksheet is always stored in a workbook. A
workbook can contain many worksheeks.
What are the 4 major parts of Excel?
 Workbook - like a notebook, Excel creates an empty workbook when it starts (Book1)
 Worksheets - sheets inside the workbook. (3 sheets (default) max is 255)

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 Sheet tab - tabs at bottom of Workbook containing each sheets name.
 Tab scrolling buttons - can be used to scroll through the sheet tabs.
These are the 5 basic Excel functions that everyone should know:
The VLookup Function.
 The Concatenate Function.
 Text to Columns.
 Remove Duplicates.
 Pivot Tables.
What are the 5 types of Excel?
Excel Charts - Types
 Column Chart.
 Line Chart.
 Pie Chart.
 Doughnut Chart.
 Bar Chart.
 Area Chart.
 XY (Scatter) Chart.
 Bubble Chart.
What are the 5 disadvantages of spreadsheet?

The Main Disadvantages of Spreadsheets:

 Lack of collaboration. ...
 Vulnerable to costly human errors. ...
 Manual process. ...
 Unable to make quick decisions about your deals. ...
 Lack of version control. ...
 Dependant on one person. ...
 Unfit for remote working. ...
 Time consuming.

What is PowerPoint in explain?

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 Microsoft PowerPoint is a powerful slide show presentation program. It is a standard
component of the company's Microsoft Office suite software, and is bundled together
with Word, Excel, and other office productivity tools. The program uses slides to convey
information rich in multimedia.
What are the 5 functions of PowerPoint?
Overview
 Create presentations from scratch or a template.
 Add text, images, art, and videos.
 Select a professional design with PowerPoint Designer.
 Add transitions, animations, and cinematic motion.
 Save to OneDrive, to get to your presentations from your computer, tablet, or phone.
What are the advantages and disadvatages of PowerPoint
 It can be used virtually anywhere. ...
 It is a collaborative solution. ...
 You can choose to create your own design or use existing ones. ...
 Multiple uses. ...
 Export in different formats. ...
 It facilitates an effective way of communication with the audience.
Disadvantages of PowerPoint presentation
 High potential for technical problems. ...
 Excessive information use. ...
 Death-predisposing PowerPoint. ...
 Presenters rely too much on their slides. ...
 Using presentations too much. ...
 Based on the slides. ...
 Technical problems. ...
 Lack of expertise

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