Computer

System
Servicing
What is COMPUTER?
 Computer, machine that performs tasks, such as calculations or
electronic communication, under the control of a set of
instructions called a program.
 Programs usually reside within the computer and are retrieved and
processed by the computer’s electronics.
 The program results are stored or routed to output devices, such as
video display monitors or printers. Computers perform a wide
variety of activities reliably, accurately, and quickly.
 TYPES OF COMPUTER
ANALOG COMPUTERS - These are almost extinct today.
These are different from a digital computer because an
analog computer can perform several mathematical
operations simultaneously. It uses continuous variables for
mathematical operations and utilizes mechanical or electrical
energy.

HYBRID COMPUTERS - These computers are a

combination of both digital and analog computers. In
this type of computers, the digital segments perform
process control by conversion of analog signals to
digital ones.
MAINFRAME COMPUTERS- Large
organizations use mainframes for highly
critical applications such as bulk data
processing and ERP. Most of the mainframe
computers have the capacities to host
multiple operating systems and operate as a
number of virtual machines and can thus
substitute for several small servers.
MICROCOMPUTERS - A computer with a
microprocessor and its central processing unit is known
as a microcomputer. They do not occupy space as much
as mainframes. When supplemented with a keyboard
and a mouse, microcomputers can be called as personal
computers. A monitor, a keyboard and other similar
input output devices, computer memory in the form of
RAM and a power supply unit come packaged in a
microcomputer. These computers can fit on desks or
tables and serve as the best choices for single-user tasks
Personal computers come in a variety of forms such as
desktops, laptops and personal digital assistants. Let us
look at each of these types of computers.
DESKTOPS - A desktop is intended to be used on a single location.
The spare parts of a desktop computer are readily available at relative
lower costs. Power consumption is not as critical as that in laptops.
Desktops are widely popular for daily use in workplaces and
households.

LAPTOPS - Similar in operation to desktops, laptop computers are

miniaturized and optimized for mobile use. Laptops run on a single
battery or an external adapter that charges the computer batteries.
They are enabled with an inbuilt keyboard, touch pad acting as a
mouse and a liquid crystal display. Its portability and capacity to
operate on battery power have served as a boon for mobile users.
PERSONAL DIGITAL ASSISTANTS (PDAs)
- It is a handheld computer and popularly
known as a palmtop. It has a touch screen and a
memory card for storage of data. PDAs can also
be effectively used as portable audio players,
web browsers and smart phones. Most of them
can access the Internet by means of Bluetooth or
Wi-Fi communication.
MINICOMPUTERS - In terms of size and
processing capacity, minicomputers lie in between
mainframes and microcomputers. Minicomputers
are also called midrange systems or workstations.
The term began to be popularly used in the 1960s to
refer to relatively smaller third generation
computers. They took up the space that would be
needed for a refrigerator or two and used transistor
and core memory technologies. The 12-bit PDP-8
minicomputer of the Digital Equipment Corporation
was the first successful minicomputer.
SUPERCOMPUTERS - The highly
calculation-intensive tasks can be
effectively performed by means of
supercomputers. Quantum physics,
mechanics, weather forecasting, molecular
theory are best studied by means of
supercomputers. Their ability of parallel
processing and their well-designed memory
hierarchy give the supercomputers large
transaction processing powers.
WEARABLE COMPUTERS - A record-setting step
in the evolution of computers was the creation of
wearable computers. These computers can be worn
on the body and are often used in the study of
behavior modeling and human health. Military and
health professionals have incorporated wearable
computers into their daily routine, as a part of such
studies. When the users’ hands and sensory organs
are engaged in other activities, wearable computers
are of great help in tracking human actions.
Wearable computers are consistently in operation as
they do not have to be turned on and off and are
constantly interacting with the user.
 DEFINITION OF TERMS
BIN - a container or enclosed space for storage.
COMPUTER CHASSIS - the enclosure that contains most of the components of a computer.
DIAGNOSTIC TOOLS - used to test the integrity of circuits and the quality of electricity in
computer components and to test the functionality of computer ports.
HAZARDS - risks; dangers.
INSULATION - a material that reduces or prevents the transmission of heat or sound or
electricity.
NOZZLE - a projecting part with an opening, as at the end of a hose, for regulating and directing
a flow of fluid.
PREVENTIVE - intended or used to prevent or hinder.
STATIC ELECTRICITY - an accumulation of electric charge on an insulated body.
TOOL - a handheld device that aids in accomplishing a task.
TOOLKIT - a set of tools designed to be used together or for a particular purpose.
ESD
 PROPER TOOL SELECTION
A tool is a handheld device that aids in accomplishing a task. Tools range
from a traditional metal cutting part of a machine to an element of a
computer program that activates and controls a particular function.

Safe Use of tools

 Once selected, use the tool for the purpose for which it was designed. Not
all tools come with detailed instructions, but there are those that do spell
out the safety ―Do’s and Don’ts for the your safety. If there are set-up/use
options, operator judgment must always be based on what is the safest way
to use the tool.
Environmental Safety and Health Program requires the following:

• All tools be kept in good condition with regular maintenance

• The right tool be used for the job
• Each tool be examined before use AND damaged or defective tools
NOT to be used
• Tools be operated according to manufacturer’s instructions
• The right protective equipment for the tool and activity be used
 HARDWARE TOOLS

 To complete hardware repairs, it is important to have a toolkit that

should contain all of the necessary tools. As you gain experience,
you will learn which tools to have available for different types of
jobs. Hardware tools are grouped into these four categories:
1. Electro-Static Discharge (ESD)
2. Tools Hand tools
3. Cleaning tools
4. Diagnostic tools
 Electro-Static Discharge (ESD) Tools
STATIC ELECTRICITY is easily generated by friction on carpets, tile flooring, clothing, hair,
fabric, and etc. The friction of moving air alone will charge suspended particles and cause the
buildup of static electrical charges on people and objects in the environment. Grounded
antistatic work mats used with antistatic wrist straps provide the most basic means for the
controlled discharge of electrostatic electricity. Examples of ESD Tools:

Anti-static wrist strap –used to prevent ESD damage to computer

equipment.

Anti-static mat – used to stand on or place

hardware on to prevent
Hand Tools A hand tool is a device for performing work on a material or a physical system
using only hands. The hand tools can be manually used employing force, or electrically
powered, using electrical current.
Examples of Hand Tools:

FLAT HEAD SCREWDRIVER –used to loosen or tighten

slotted screw

PHILIPS HEAD SCREWDRIVER – used to loosen or tighten cross- heads

screws
TORX SCREW DRIVER -used to loosen or tighten screws that have a
star-like depression the top a feature that is mainly found on laptop.

HEX DRIVER– sometimes called a nut driver, is used to

tighten nuts in the same as crew driver tightens screws.

NEEDLE-NOSE PLIER – used to hold small parts.

 WIRE CUTTER – used to strip and cut wires.

TWEEZERS – used to manipulate small parts.

PART RETRIEVER – used to retrieve parts from location that are to small
for your hand to fit.

FLASHLIGHT – used to light up areas that you cannot see well.

 Cleaning Tools
Having the appropriate cleaning tools is essential when maintaining or repairing computers.
Using these tools ensures that computer components are not damaged during cleaning. Examples:

LINT-FREE CLOTH–used to clean different

computer components with out scratching.

COMPRESSED AIR – used to blow away dust and debris from

different computer different computer parts without touching the
components.
CABLE TIES – used to bundle cables neatly inside and
outside of a computer.

PARTS ORGANIZER – used to hold screw, jumpers,

fasteners and other small parts and prevents them from
getting mixed together.
Diagnostic Tools
Computers are easier to use and more dependable with each new generation of
hardware and operating system update, but that doesn't mean they're problem-
free. Here's the most popular tools for diagnosing your computer problems:

MULTIMETER– used to test the integrity of circuits and

the quality of electricity in computer components.

Loop back Adapter

 Perform Mensuration and Calculation
Bit - a fundamental unit of information having just two possible values,
as either of the binary digits 0 or 1.
Byte - a unit of digital information in computing and
telecommunications that most commonly consists of eight bits.
Booting – starting (a computer) by loading an operating system from a
disk.
Electronic storage - a device for recording (storing) information (data).
Firewire - Apple Computer's version of a standard, IEEE 1394, High
Performance Serial Bus, for connecting devices to your personal
computer.
Hot-swappable - the connection and disconnection of
peripherals or other components without interrupting system
operation.
Interface - the point of interaction or communication between a
computer and any other entity, such as a printer or human
operator.
Laser - a device that emits light (electromagnetic radiation)
through a process of optical amplification based on the
stimulated emission of photons.
Magnetic platter - a thin, high precision disk that is coated on
both sides with a high precision magnetic material and which
is used in a hard disk drive (HDD) to store data. Memory
Magnetic storage media - any storage medium in which
different patterns of magnetization are used to represent stored
bits or bytes of information
Operating system - a set of programs that manage computer
hardware resources and provide common services for
application software.
Optical storage media - any storage in which data is written and
read with a laser for archival or backup purposes.
HDD – hard disk drive
IDE - Integrated Drive Electronics