Pc maintenance

CHAPTER 1
Introduction to Computer System

By FITA AYALEW

Objectives
 Learn that a computer requires both hardware and software
to work
 Learn about the many different hardware
 Investigate components inside of and connected to a
computer
 Study how to:-
 Install new hardware and software
 Diagnose hardware and software problems
 Solve hardware and software problems
 Evaluate new hardware and operating systems

By FITA AYALEW

INTRODUCTION
Hardware Needs Software to Work
• Hardware: physical portion of a computer
– Components: monitor, keyboard, memory, hard drive
• Software: instructions used to manipulate hardware
– Requirements: input, processing, storage, output
• All hardware operations are based on binary values
• Binary number system consists of two digits: 0 and 1
• Fundamental groupings of binary numbers:
– Bit: binary digit that can take on values of 0 or 1
– Nibble: four bits
– Byte: eight bits

By FITA AYALEW

Figure 1-1
All communication, storage,
and processing of data inside a computer
are in binary form until presented as output
to the user

By FITA AYALEW

PC Hardware Components
 Most input/output (I/O) devices are external to case
 Most processing and storage devices are internal
 Central processing unit (CPU)
 Also called the processor or microprocessor
 Reads input, processes data, writes data to storage
 Elements required by I/O and storage devices
 A method for CPU to communicate with the device
 Software to instruct and control the device
 Electricity to power the device

By FITA AYALEW

Hardware Used for Input and Output
 Connections to the case can be cabled or wireless
 Port: access point located in back or front of case
 Chief input devices:
 Keyboard: enhanced type holds 104 keys
 Mouse: pointing device used to select screen items
 Chief output devices:
 Monitor: visually displays primary output of computer
 Printer: produces output on paper (hard copy)

By FITA AYALEW

Hardware Inside the Computer Case
 Most storage and processing occurs in the case
 Internal devices common to most computers:
 Motherboard containing CPU, memory, other parts
 Floppy drive, hard drive, CD drive for persistent storage
 Power supply with power cords supplying electricity
 Circuit boards for internal and external communication
 Cables to connect devices to all circuit boards

By FITA AYALEW

Figure 1-2 Inside the computer case

By FITA AYALEW

The Motherboard
 The largest and most important circuit board
 Also known as the main board or system board
 Contains the CPU, expansion slots, other devices
 Categories used to group motherboard components
 Processing, temporary storage, communication, power
 All devices communicate with CPU on motherboard
 A peripheral device links to motherboard via cable
 Some motherboard ports outside of the case:
 Keyboard, mouse, parallel, USB ports, sound ports

By FITA AYALEW

Figure 1-4
All hardware components are either located on the
motherboard or directly or indirectly connected to it because they
must all communicate with the CPU

By FITA AYALEW

Figure 1-5 A motherboard provides ports
for common I/O devices

By FITA AYALEW

The Processor and the Chipset
 CPU: chip that performs most data processing
 Chipset: group of microchips controlling data flow
 Personal computer (PC): chief focus of this text
 Major manufacturers of CPUs and chipsets for PCs
 Intel Corporation, AMD, VIA, SiS, and Cyrix

By FITA AYALEW

Figure 1-6
This motherboard uses two chips in its chipset (notice the bus lines
coming from each chip used for communication)

By FITA AYALEW

Storage Devices
 Primary storage (main memory):
 Temporary storage used by the processor
 Example: RAM (random access memory)
 Secondary storage (permanent storage):
 Enables data to persist after the machine is turned off
 Examples: hard drive, CD, floppy disk
 Analogy to primary-secondary memory relationship
 Book stacks in a library are like permanent storage
 Books can be moved to a desk (temporary storage)

By FITA AYALEW

Primary Storage
 RAM (random access memory):
 Device providing temporary storage
 Located on motherboard and on other circuit boards
 Three types of RAM boards (memory modules):
 DIMM (dual inline memory module)
 RIMM (Rambus inline memory module)
 SIMM (single inline memory module)
 RAM is volatile (data does not persist)
 ROM (read-only memory) is nonvolatile

By FITA AYALEW

Figure 1-6
SIMM, DIMM, or RIMM holds RAM and
is mounted directly on a motherboard

By FITA AYALEW

Secondary Storage
 Hard drive
 Case containing disks that rotate at high speeds
 An arm with a read/write head traverses the platter
 Integrated Drive Electronics (IDE)
 Technology used internally by a hard drive
 ATA (AT Attachment) standard
 Specifies motherboard-hard drive interface
 Types: Serial ATA or parallel ATA (Enhanced IDE)
 Parallel ATA accommodates up to four IDE devices

By FITA AYALEW

Figure 1-7
Two IDE devices connected to a motherboard
using both IDE connections and two cable

By FITA AYALEW

Secondary Storage …(continued)

 Serial ATA standard
 Allows for more than four drives in a system
 Applies only to hard drives and not to other drives
 Some IDE devices: hard drives, Zip drives, CD drive
 Floppy drive
 3.5-inch disk holding 1.44 MB of data
 Floppy drive connector is distinct from IDE connectors
 CD-ROM (compact disc read-only memory) drive
 Standard equipment for reading software distributions

By FITA AYALEW

Motherboard Components Used For
Communication Among Devices
 Traces: circuits or paths that move data and power
 Bus: system of pathways and transmission protocols
 Data bus
 Lines in a bus that carry the data
 Binary bits correspond to voltage values of on or off
 Data path sizes: 8, 16, 32, 64, or 128 bits wide
 Main bus on motherboard (system bus, memory bus)
 Communicates with CPU, memory, and chipset
 Pulse of system clock carried by line on motherboard

By FITA AYALEW

Motherboard Components Used For
Communication Among Devices
…(continued)
 Devices work according to beats (or cycles)
 Clock speed is measured in hertz (cycles/second)
 One megahertz (MHz): one million cycles per second
 One gigahertz (GHz): one billion cycles per second
 Common ratings for motherboard buses
 1066 MHz, 800 MHz, 533 MHz, or 400 MHz
 Range of CPU speeds: 166 MHz to 4 GHz
 Buses for expansion slots: PCI, AGP, ISA

By FITA AYALEW

Figure 1-8
PCI bus expansion slots are shorter than ISA slots and offset further; the one
AGP slot is set farther from the edge of the board

By FITA AYALEW

Interface (Expansion) Cards
 Some names for circuits mounted in expansion slots:
 Circuit cards, adapter boards, expansion cards, cards
 Cards that connect the CPU to an external device:
 Video: provides a port for the monitor
 Sound: provides ports for speakers and microphones
 Network: provides a port for a network cable
 Modem: provides ports for phone lines
 Determine a card’s function by identifying its port

By FITA AYALEW

Figure 1-9
This circuit board is a modem card and is mounted in a PCI slot on the
motherboard

By FITA AYALEW

The Electrical System
 Power supply
 Most important electrical component
 Converts AC voltage external source to DC voltage
 Reduces voltage from 110-220 volts to 12 volts or less
 Runs a fan to cool the inside of the computer case
 Temperatures > 185° F can cause component failure
 Motherboard has 1 or 2 connections to power supply

By FITA AYALEW

Figure 1-10
The motherboard receives its power from the power supply by way of one or more
connections located near the edge of the board or near the processor

By FITA AYALEW

Instructions Stored on the
Motherboard and Other Boards

 BIOS (basic input/output system)
 Data and instructions stored on ROM chips
 ROM BIOS chips are a type of firmware
 Three purposes served by motherboard ROM BIOS:
 System BIOS: used to manage simple devices
 Startup BIOS: used to start the computer
 CMOS setup: used to change motherboard settings
 CMOS RAM: includes date, time, port configurations
 Flash ROM: ROM chips that can be overwritten

By FITA AYALEW

Figure 1-11
This firmware chip contains flash ROM and CMOS RAM; CMOS RAM
is powered by the coin battery located near the chip

By FITA AYALEW

Plug and Play
 Also known as PnP
 Standard simplifying installation of hardware devices
 PnP BIOS begins process of configuring devices
 PnP-compliant operating system completes
configuration
 ESCD (extended system configuration data) Plug and
Play BIOS
 Enhanced version of PnP
 Stores manual configuration steps

By FITA AYALEW

Summary
 A computer comprises hardware and software
 Main functions: input, output, processing, storage
 Data is stored in a binary format (1 or 0, on or off)
 Input/output devices: keyboard, mouse, printer, monitor
 Motherboard (system board): contains the CPU, access to other circuit
boards and peripherals
 Primary storage (RAM) is volatile (temporary)
 Secondary storage is nonvolatile (permanent)
 Parallel and serial ATA standards: enable secondary storage devices to
interface with the motherboard
 Computer bus: system of communication pathways and protocols
 ROM BIOS helps start PCs, manage simple devices, and change some
motherboard settings

By FITA AYALEW

CHAPTER 2
Operating System Basics

By FITA AYALEW

Objectives
 Learn about the various operating systems and the
differences between them
 Learn how an OS interfaces with users, files and
folders, applications, and hardware
 Learn about a few OS tools you can use to examine and
maintain a system

By FITA AYALEW

Operating Systems Past and Present
 What an operating system (OS) does:
 Manages hardware
 Runs applications
 Provides an interface for users
 Retrieves and manipulates files
 The OS can be analogized to a “middleman”
 A computer needs only one operating system
 Operating systems have evolved to a complex form

By FITA AYALEW

Figure 2-1
Users and applications depend on the OS: to relate to all applications and
hardware components

By FITA AYALEW

What an Operating System Does
 Four functions common to all operating systems:
 Providing a user interface
 Managing files
 Managing applications
 Managing hardware
 All OSs also have similar core components

By FITA AYALEW

Operating System Components
 Components common to all OSs: shell and kernel
 The shell exposes functions to users and applications
 Example 1: enables user to select a CD
 Example 2: enables application to print a document
 The kernel (core) interacts with hardware devices
 Example: passes a print request to a printer device
 Registry database and initialization files
 Used to store configuration information in Windows

By FITA AYALEW

Figure 2-2
Inside an operating system, different components perform various
functions

By FITA AYALEW

An OS Provides a User Interface
 Sequence of events occurring after PC is turned on
 The operating system is loaded
 Running OS provides an interface (desktop)
 OS awaits an event, such as a double-click
 A user can initiate an event in several ways:
 Click a menu item
 Enter a command in Run dialog or command console
 Double-click an icon

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An OS Manages Files and Folders
 File system: organizes files and folders
 File systems used by Windows for hard drives:
 File Allocation Table (FAT): tracks disk space usage
 New Technology File System (NTFS): replacing FAT
 Organization of a hard drive or floppy disk
 Platter contains concentric tracks
 Track contains 512 byte sectors
 Cluster contains one or more sectors
 Cluster is the smallest unit on disk for storing a file

By FITA AYALEW

An OS Manages Applications
 The OS installs and runs all other PC software
 Application: software providing services for users
 Applications rely on the OS for support operations
 Example: MS word relies on OS to manage memory
 Applications are typically tailored to a single OS
 Ensure that OS is suitable for a given application

By FITA AYALEW

An OS Manages Hardware
 OS interacts with hardware using drivers or BIOS
 Software falls into three categories:
 Device drivers or the BIOS
 Operating system
 Application software

By FITA AYALEW

Summary
 The OS manages system resources for users and Applications
 DOS (disk operating system): early command driven OS
 Modern OSs: Windows 2000/XP, Linux, Mac OS X
 Operating systems are divided into a kernel and user shell
 OS functions: providing a user interface, managing files,
managing applications, and managing hardware

By FITA AYALEW

CHAPTER 3
PC Repair Fundamentals and safety
precautions

By FITA AYALEW

Objectives
 Learn about tools you’ll need as a PC support
technician
 Learn how to develop a preventive maintenance plan
and what to include in it
 Learn how to work inside a computer case
 Learn how to approach and solve a PC problem

By FITA AYALEW

PC Support Technician Tools
 Help you maintain a computer
 Help you diagnose and repair computer problems
 Criteria for choosing tools:
 Level of PC support you expect to provide
 Amount of money you can spend
 Some essential tools:
 Ground bracelet, ground mat, or ground gloves
 Torx screwdriver set
 Recovery CD, DVD, or floppy disk for target OS
 Store tools in toolbox for PC troubleshooting

By FITA AYALEW

Figure 3-1
PC support technician tools

By FITA AYALEW

Recovery CDs
 Used to boot a system
 Also used to repair and reinstall Windows
 Primary recovery CD sources
 PC manufacturer (preferred)
 Operating system distributor, such as Microsoft
 Some hard drives have a hidden recovery partitions
 A hidden partition can be used to reinstall Windows
 A utility for creating recovery CDs may be provided
 Access hidden utilities by pressing a Fn key at startup

By FITA AYALEW

Loop-Back Plugs
• Used to test various ports
– Some port types: serial, parallel, USB, network
• How to use a loop-back plug
– Plug in the loop-back plug
– Run the software that comes with the plug

By FITA AYALEW

Cleaning Pads and Solutions
 Various types are designed for specific uses
 Example: contact cleaner
 Cleans contacts on expansion cards
 Warning: solutions may be flammable and/or toxic
 Sources of safety and emergency instructions:
 Side of the can of solution
 Material safety data sheet (MSDS)
 Adhere to safety procedures of your employer
 Example: fill out an accident report (if required)

By FITA AYALEW

Post Diagnostic Cards
 Report computer errors and conflicts at POST
 How to use a POST diagnostic card:
 Install card in an expansion slot on the motherboard
 Attempt to boot your system
 Record any error codes appearing in LED panel
 Look up the entry associated with the error code
 Examples of Post diagnostic cards:
 PCI Error Testing/Debug Card by Winic Corporation
 POST card V3 by Unicore Software, Inc.
 Post Code Master by MSD, Inc.

By FITA AYALEW

Figure 3-2
Post Code Master diagnostic card by MSD, Inc.

By FITA AYALEW

Personal Computer Preventive
Maintenance

 Preventive maintenance reduces number of problems
 Goals of preventive maintenance plans:
 Prevent failures
 Reduce repair costs
 Reduce downtimes
 Goal of disaster recovery plan: manage failures
 Some causes of PC failure: heat, dust, spills, viruses

By FITA AYALEW

When a PC is your Permanent
Responsibility

 Tasks and procedures to prepare for troubleshooting
 Keep good backups of data and system files
 Document all setup changes, problems, and solutions
 Protect the system against viruses and other attacks
 Always use a firewall (software or hardware barrier)
 Install and run antivirus software
 Keep Windows Updates current
 Physically protect your equipment

By FITA AYALEW

Creating a Preventive Maintenance
Plan
 Plan based on history or pattern of malfunctions
 Example: PCs in dusty areas need more maintenance
 Goals common to maintenance plans
 Extend the working life of a PC
 Anticipate problems that could disrupt service
 Ensure data is secure and backed up
 Provide support to PC users
 Basic steps involved in designing a plan
 Define your overall goals
 Incorporate procedures for achieving goals

By FITA AYALEW

Dealing with Dust
 Dust accumulates in layers over components
 Two major problems due to dust blankets
 PC components directly overheat
 Cooling fans jam, also resulting in overheating

 Maintenance task: remove the layer of dust
 Two tools used to remove dust:
 Antistatic vacuum
 Compressed air

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How to Work Inside a Computer Case

 Objective: dismantle a computer, put it back together
 Some safety precautions to follow:
 Make notes that will help you backtrack
 Keep screws and spacers orderly
 Do not stack boards on top of each other
 Do not touch the chips on circuit boards
 Do not use a graphite pencil to change DIP settings
 Turn off the power, unplug and ground the computer
 Do not remove covers of monitors or power supplies
 Keep components away from hair and clothing

By FITA AYALEW

Static Electricity
 Build-up of charge due to absence of conductors
 Electrostatic discharge (ESD)
 Due to dissimilar electrical surfaces making contact
 Only 10 volts of ESD can damage PC components
 Walking across carpet generates up to 12,000 volts

 Two types of damage: catastrophic and upset failure
 Tool and methods for grounding yourself and the PC
 Ground bracelet, ground mats, static shielding bags, antistatic gloves

By FITA AYALEW

Figure 3-3
A ground bracelet, which protects computer components from ESD, can clip to
the side of the computer case and eliminate ESD between you and the case

By FITA AYALEW

Steps to Take Apart a Computer
 Essential tools:
 Ground bracelet
 Phillips-head screwdriver
 Flat-head screwdriver, paper, and pen

 Follow safety precautions at all times
 Summary of Steps 1 – 4
 1. Enter CMOS and write down customized settings
 2. Power down the system, unplug all components
 3. Put the computer on a good-sized table
 4. Remove the cover of the PC

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Figure 3-4
Removing the cover

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Steps to Take Apart a Computer (continued)

 Summary of steps 5 - 11
 5. Diagram cable connections and switch settings
 6. Identify cables connecting drives to motherboard
 7. Remove the cables to all drives
 8. Remove the expansion cards
 9. Remove the motherboard (or drives)
 10. Remove the power supply from the case
 11. Remove each drive (if not already removed)

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Figure 3-5
Remove the motherboard from the case
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Steps to Put a Computer Back Together

1. Install power supply, drives, motherboard, cards
2. Connect all data and power cables
3. Plug in the keyboard, monitor, and mouse
4. Ask instructor to check work (if in a classroom)
5. Turn on the power and check PC functions

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Fundamental Rules for PC Troubleshooting
 Approach the problem systematically
 Divide and conquer
 Don’t overlook the obvious
 Check the simple things first
 Make no assumptions
 Become a researcher
 Write things down
 Reboot and start over
 Establish your priorities
 Don’t assume the worst
 Know your starting point

By FITA AYALEW

Figure 3-6
General approach to troubleshooting

By FITA AYALEW

Summary
 Some PC repair tools: recovery
CDs, screwdrivers, POST, cleaning pads and
solutions, diagnostic cards
 Preventive maintenance plans extend the life of a PC
 Follow an organization’s preventive maintenance plan, or
develop one if it does not exist
 Computers present chemical and electrical hazards
 Protect components in case from ESD by grounding
yourself and the PC
 Assembling and reassembling a PC prepares the technician
for actual repair work
 Expert troubleshooters ask good questions
 Before tackling a problem, develop a game plan
By FITA AYALEW

PC maintenance and
Troubleshooting
Chapter 4
Computer Case, Electricity, and
Power Supplies
By FITA AYALEW

Objectives
 Select an appropriate case for a PC
 Understand electrical basics
 Select an appropriate power supply
 Troubleshoot a PC using electrical testing
 Select appropriate power conditioning and backup
devices

By FITA AYALEW

Case Form Factors
ATX:
– Loose wires coming from power
switch, will connect to
motherboard later
– Bezel for the motherboard’s
built-in I/O ports in back

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Case Form Factors
• AT:
– Power switch connects to
power supply
– Slots in case floor for
plastic standoffs

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Towers and Desktop cases

Figure 4-1
Towers and Desktop Cases
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Measures and Properties of Electricity

 Successful PC technicians:
 Understand electricity
 Know how to use electricity
 Know how to measure electricity
 Can protect computer equipment from electricity
 Units used to measure characteristics of electricity
 Volt, amp, ohm, and watt

By FITA AYALEW

Electricity Basics
 Voltage
 Difference in charge between the positive and negative
poles
 Can be positive or negative volts (v)
 Ordinary household current is 110v in the USA, or 220v
in most of Europe

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AC and DC
 AC: Alternating Current
 Ordinary household current
 Alternates positive and negative poles at 60 Hz
 Good for sending power over long distances
 DC: Direct current
 Batteries
 Positive and negative poles stay fixed
 Lower overhead

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Some Common Electric Components
 Materials used to make components:
 Conductors: weakly resist flow of current; e.g., copper
 Insulators: highly resist flow of current; e.g., ceramics
 Semiconductors: allow flow if charged; e.g., silicon
 Transistor
 Used to switch current on (1) and off (0)
 Also used to amplify current
 Made of three layers of semiconductor material
 Charge applied to center layer controls switching
 Capacitor
 Holds electrical charge for a period of time
 Used to create even flow of current in a PC
 Diode
 Allows electricity to flow in one direction only
 Used to rectify current (convert AC to DC)
 Resistor
 Controls the amount of current flowing through

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Electrical Measurements
• Analog multimeter
• Uses a needle gauge
• Continuously variable
• Digital multimeter
• Uses a digital display
• Precise values
• More suitable for
computers

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Measuring Voltage

• Must be measured with
computer on
• Use back-probing
• Place black probe on
grounding wire (black)
• Place red probe on

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Types of Power Supplies
• Form factor
AT
ATX
Other sizes
• Wattage

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AT Power Supply
 P8 and P9 connectors to motherboard
 Power switch attached directly
 +5v, -5v, +12v, and -12v power

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AT Connectors

Figure 4-2
AT Connectors
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ATX Power Supply

 Single 20-wire connector to motherboard
 No direct connection to power switch
 +5v, -5v, +12v, -12v, and +3.3v power

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ATX Power Supply Wires

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Power Supply Connectors
 • Molex
 – Used for most drive types
 • Mini
 – Used for 3.5” floppy drives

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Determining Wattage Requirements
 Read label on power supply
 Calculate wattage drawn by each component
 Compare total amount drawn to label

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Computer Power Consumption
Component Requirement
Component Requirement Line(s) Component Requirement Line(s) Used Line(s) Used
Used
AGP Video Card 30 - 50W +3.3V AGP Video Card 30 - 50W +3.3V AGP Video Card 30 - 50W +3.3V

AMD Athlon Processor 70W +12V Pentium 4 Processor 70W +12V Pentium III Processor 38W +5V

RAM 8W per 128MB +3.3V Motherboard (w/o CPU or RAM) 25 - 40W +3.3V and +5V Case/CPU Fans 3W +12V

10,000rpm SCSI Drive 10 - 40W +5V and +12V 7200rpm IDE Hard Drive 5 - 20W +5V and +12V CD-RW 10 - 25W +5V and +12V

DVD-ROM 10 - 25W +5V and +12V CD-ROM 10 - 25W +5V and +12V Floppy Drive 5W +5V

SCSI Controller PCI Card 20W +3.3V and +5V 10/100 NIC 4W +3.3V Average PCI Card 5 - 10W +5V











By FITA AYALEW

Failed Power Supply
 Fan won’t spin
 Inconsistent power provided (fan revs and sags)
 System will not boot (appears dead)
 Typically overloads at startup
 Problems occur when drives spin up
 System may spontaneously reboot when multiple
drives are accessed

By FITA AYALEW

Problems with the Power Supply Fan
 Defective fans usually hum before they stop working
 Response to diagnosis of defective fan
 Replace fan or the entire power supply
 If replacement does not work, suspect another short
 Do not operate a PC if the fan does not work
 Computers will overheat, damaging circuit boards
 Indirect sources of fan problems:
 Shorts in drives, motherboard, or expansion cards

By FITA AYALEW

Problems with Overheating
 Causes intermittent problems
 May also cause the system to reboot or not boot
 Temperature in a case should not exceed 100° F
 Some possible solutions:
 Remove dust from power supply, vents, heat sink
 Secure cables and cords with tie wraps
 Install another exhaust fan on the rear of the case
 Install a fan in expansion slot next to video card
 Replace component that is damaged

By FITA AYALEW

Replacing the Power Supply
 The power supply is a field replaceable unit (FRU)
 Criteria for replacement power supply to meet:
 Uses the correct form factor
 Adequately rated for power in watts
 Has all power connectors needed by your system
 Before replacing power supply, test new device
 Connect components to new power supply
 Turn on PC and observe whether problem is solved
 If problem is solved, perform replacement procedure

By FITA AYALEW

Summary
 Form factor: specifies size, shape, features of device
 Motherboard, power supply, and case share the same form
factor, such as ATX
 Three types of cases: desktop, tower, and notebook
 Quantities that characterize electricity: voltage, current,
resistance, power
 Current flows from hot wires to neutral wires; excess
current escapes through grounds
 AC supplied by power station is transformed and rectified
before flowing into the PC
 Major components in a circuit board: transistor, capacitor,
diode, Resistor
 Electrical threats: ESD, EMI, uneven current flow, sudden
power surges (or spikes)
By FITA AYALEW

CHAPTER 5
Processors and Chipsets

By FITA AYALEW

Objectives
 Learn about the many different processors used for
personal computers and notebook computers
 Learn about chipsets and how they work
 Learn how to keep a processor cool using heat sinks
and coolers
 Learn how to install and upgrade a processor

By FITA AYALEW

Introduction
 The processor and chipset
 Most important components on the motherboard
 The chipset is embedded in the motherboard
 Processor and chipset are located on motherboard
 Components determine power and features of system
 Major manufacturers: Intel, AMD, and Cyrix
 Factors used to rate processors:
 System bus speeds supported; e.g., 1066 MHz
 Processor core frequency in gigahertz; e.g., 3.2 GHz
 Word size (32 or 64 bits) and data path (64 or 128 bits)
 Multiprocessing ability and processor specific memory
 Type of RAM, motherboard, and chipset supported

By FITA AYALEW

How a Processor Works
 Three basic components:
 Input/output (I/O) unit
 Control unit
 One or more arithmetic logic units (ALUs)
 Registers: high-speed memory used by ALU
 Internal cache: holds data to be processed by ALU
 Two types of buses:
 External (front-side) bus: data portion is 64 bits wide
 Internal (back-side) bus: data portion is 32 bits wide

By FITA AYALEW

Figure 5-1 Since the Pentium processor was first released in 1993, the standard
has been for a processor to have two arithmetic logic units so that it can process two
instructions at once

By FITA AYALEW

How a Processor Works (continued)
 System bus frequency or speed
 Faster than other buses; e.g., 1066 MHz, 800 MHz
 Processor frequency or speed
 Refers to speed of internal operations; e.g., 3.2 GHz
 System bus frequency x multiplier = processor frequency
 Overclocking: running processor at excessive speed
 Throttling: decreasing speed when overheating occurs
 Data path size and word size
 Data path: transports data into processor
 Word path: number of bits processed in one operation

By FITA AYALEW

How a Processor Works (continued)
 Multiprocessing
 Simultaneous processing by two or more ALUs
 Multiprocessor platform
 Contains two or more processors
 Dual-core processing
 Processors share system bus, but have separate cache
 Memory cache
 Static RAM (SRAM): holds data as long as power is on
 Lets processor bypass slower dynamic RAM (DRAM)
 L1 cache is on the processor chip, L2 cache is external

By FITA AYALEW

Figure 5-2 AMD dual-core processing using two Opteron in
the single processor housing
By FITA AYALEW

Figure 5-3 Cache memory (SRAM) is used to temporarily hold
data in expectation of what the processor will request next

By FITA AYALEW

Processor Sockets and Slots
 Used to connect the processor to the motherboard
 Motherboard type must match processor package
 Types of sockets
 Sockets are built around pin grid or land grid arrays
 Variations: PGA, SPGA, LGA, DIP, LIF, and ZIF
 Types of slots
 Packages fit into slots like expansion cards
 Designated slots: Slot 1, Slot A, and Slot 2
 New processor packages use sockets, not slots
 Slocket: adapts Slot 1 to processor requiring a socket

By FITA AYALEW

Figure 5-4 Socket LGA775 is the latest
Intel socket

By FITA AYALEW

Figure 5-5 A riser card can be used to install a Celeron
processor into a motherboard with slot 1

By FITA AYALEW

The Chipset
 Set of chips on the motherboard
 Controls memory cache, external buses, peripherals
 Intel dominates the market for chipsets
 Example: i800 series of chipsets
 Intel 800 series Accelerated Hub Architecture
 All I/O buses connect to a hub interface
 The hub connects to the system bus
 North Bridge: contains graphics and memory controller
 South Bridge: contains I/O controller hub
 Each bridge is controlled by a separate chipset

By FITA AYALEW

Figure 5-6 Using Intel 800 series Accelerated Hub Architecture, a
hub interface is used to connect slower I/O buses to the system bus
By FITA AYALEW

Heat Sinks and Cooling Fans
 Cooling assembly should keep temperatures <185° F
 Target temperature range: 90° - 100° F
 One or more fans are needed to meet cooling needs
 Cooling fan sits on top of processor with wire or clip
 Heat sink: clip-on device pulling heat from processor
 Cooler: combination of heat sink and cooling fan

By FITA AYALEW

Voltage to the Processor
 Earlier processors drew power from system bus lines
 Newer motherboards may have a power connector
 Modern motherboards regulate voltage to socket
 Sockets were more universal for older processors
 Processor may fit socket, but not get correct voltage
 Ensure that motherboard supports older processor
 Dual-voltage processor
 Voltages for internal and external operations differ
 Single-voltage processor: requires only one voltage

By FITA AYALEW

Figure 5-7 Auxiliary 4-pin power cord from the power
supply connects to the ATX12V connector on the motherboard to
provide power to the Pentium 4

By FITA AYALEW

Summary
 Basic CPU components: I/O unit, control unit, ALUs
 Registers: high speed memory used by ALU in current
processing
 Internal cache: holds frequently used instructions
 Types of buses in CPU: internal and external (system)
 Processors are housed inside a processor package
 Processors fit into slots or sockets in the motherboard
 The chipset controls memory cache, external buses and
some peripherals
 A cooler comprises a cooling fan and a heat sink
 A voltage regulator module (VRM) controls the amount of
voltage to a processor

By FITA AYALEW

CHAPTER 6
Motherboards

By FITA AYALEW

Objectives
 Learn about the different types of motherboards and
how to select one
 Learn how to support and configure a motherboard
 Learn how to install or replace a motherboard
 Learn how to troubleshoot a motherboard and
processor

By FITA AYALEW

Selecting a Motherboard
 Motherboard form factor
 Determines the size of the board
 Drives selection of power supply, case, CPU, cards
 ATX: most popular motherboard form factor
 BTX: the latest motherboard form factor
 Three types of motherboards you can select:
 A board providing the most room for expansion
 A board suiting the computer’s current configuration
 A board falling in between current and future needs

By FITA AYALEW

Figure 6-1 An ATX motherboard with PCI Express and
Socket 775

By FITA AYALEW

Selecting a Motherboard (continued)
 Some questions to ask when picking a motherboard
 What form factor does the motherboard use?
 Does the motherboard provide proper CPU support?
 What type of BIOS does the motherboard use?
 Does the board fit the case you plan to use?
 What is the warranty on the board?
 Embedded (on-board) component
 Component located on the board
 Avoid board with too many embedded components
 Such boards do not easily accept add-on devices

By FITA AYALEW

Configuring and Supporting a Motherboard
 Components that require configuration and support:
 Expansion slots
 Internal and external connectors
 Expansion slots are supported by buses
 Before configuring slots, learn about buses
 Buses are like highway transportation systems
 Facilitate communication among devices
 Four types of cargo carried by a bus:
 Power,
 control signals,
 memory addresses,
 data

By FITA AYALEW

Figure 6-2 How PCI Express connects to the
chipset and processor
By FITA AYALEW

Hardware Configuration (continued)
 CMOS setup program
 Can be accessed without opening the case
 Stored on a floppy disk or ROM BIOS chip
 Access built-in program by pressing key during POST
 Menus: Main, Advanced, Power, Boot, and Exit
 Brand name PCs, such as IBM, have custom screens

By FITA AYALEW

Table 6-1 How to access CMOS setup

By FITA AYALEW

Figure 6-2 CMOS Setup Main menu
By FITA AYALEW

Hardware Configuration (continued)
 Battery power to CMOS
 Enables CMOS to hold data after the PC is turned off
 Setup information is lost if battery fails or disconnects
 Startup passwords in CMOS
 Stored in CMOS and changed in setup screen
 Should be distinguished from OS passwords
 CMOS settings are specified in motherboard manuals
 Documentation of configuration settings
 Enables you to recapture lost or altered settings
 Should be labeled and stored in a safe place

By FITA AYALEW

Flashing ROM BIOS
 Programs stored in the ROM BIOS chip:
 CMOS setup program
 Startup BIOS that manages the startup process
 System BIOS that manages basic I/O functions
 Programs on ROM BIOS may need upgrades
 Flashing: upgrading or refreshing ROM BIOS chip
 Sources for ROM BIOS upgrades
 Manufacturer’s Web site

By FITA AYALEW

Replacing a Motherboard
 Overview of the replacement process
1. Verify that you have selected the right motherboard
2. Determine the power configuration settings
3. Remove components to reach the old motherboard
4. Set any jumpers or switches on the motherboard
5. Install the processor and processor cooler
6. Install RAM into appropriate slots on motherboard
7. Install the motherboard
8. Attach cabling (case switches, power supply, drives)
9. Install the video card on the motherboard

By FITA AYALEW

Replacing a Motherboard (continued)
 Overview of the replacement process (continued)
10. Plug in PC and then attach monitor and keyboard
11. Boot the system and enter CMOS setup
12. Make sure the settings are set to default
13. Observe POST and verify that no error occurs
14. Check for conflicts with system resources
15. Install the motherboard drives
16. Install any other expansion cards and drives
17. Verify the system is up and running
By FITA AYALEW

Installing the Motherboard in the Case
 Overview of the eight general steps:
1. Install the faceplate (I/O shield)
2. Install the standoffs (spacers)
3. Secure the motherboard in the case
4. Connect the power cord to the PI power connection
5. Connect 4-pin auxiliary power cord to motherboard
6. Connect the wire leads from front panel of case
7. Refer to manual to verify wire to pin connection
8. Connect USB connection (if present) to USB ports
By FITA AYALEW

Completing the Installation
 Following the connection of cables and cords
 Install the video card
 Plug in the keyboard and monitor
 Turn the system on
 Look out for errors during POST
 Install drivers from CD bundled with motherboard
 Verify operations
 Make OS and CMOS adjustments as needed

By FITA AYALEW

Problems with Installations
 If CPU was added to working motherboard, check:
 Thermal paste between CPU and heat sink
 Fastening between cooler and motherboard frame
 Pins or lands on the socket and processor
 Things to check if new motherboard is not working:
 Whether the front cover of the case is installed
 Whether the power switch on back of the case is on
 Incorrect connections
 Installation of CPU, thermal compound, and cooler
 Installation of all motherboard drivers on the CD

By FITA AYALEW

Summary
 Motherboard form factor drives selection of motherboard
 Configurable components: bus, expansion slots, other
connectors
 Cargo carried by a computer bus: electrical power, control
signals, memory address, data
 Bus types: local, local video, local I/O, expansion
 The CMOS setup program is stored on a floppy disk or
ROM BIOS chip
 Document configuration settings for recovery needs
 Upgrade ROM BIOS using a technique called flashing
 Use POST reporting to help diagnose problems

By FITA AYALEW

CHAPTER 7
Upgrading Memory

By FITA AYALEW

Objectives
 Learn about the different kinds of physical memory
and how they work
 Learn how to upgrade memory
 Learn how to troubleshoot problems with memory
 Memory technologies have evolved rapidly
 Study development to grasp current technology
 Memory-related tasks performed by a PC technician
 Upgrading memory
 Adding more memory to a system
 Troubleshooting problems with memory

By FITA AYALEW

RAM Technologies
 RAM (random access memory)
 Holds data and instructions used by CPU
 Volatile (data does not persist after PC is turned off)
 ROM (read-only memory)
 In firmware on motherboard; e.g., ROM BIOS
 Non-volatile (retains data after PC is turned off)
 Reviewing other salient features of RAM
 RAM is stored in modules: DIMMs, RIMMs, SIMMs
 Types: static RAM (SRAM) and dynamic RAM (DRAM)
 Memory cache is made up of SRAM (it is faster)

By FITA AYALEW

Figure 7-1 DRAM on most motherboards today is stored on
DIMMs

By FITA AYALEW

RAM Technologies (continued)
 Differences among DIMM, RIMM, and SIMM modules
 Width of the data path each module accommodates
 The way data moves from system bus to the module
 Older DRAM worked asynchronously with system bus
 Newer DRAM works synchronously with system bus
 Retrieves data faster as it keeps time with system clock
 Goal of each new technology
 Increase overall throughput while retaining accuracy

By FITA AYALEW

Figure 7-2 Types of memory modules
By FITA AYALEW

SIMM Technologies
 SIMMS have a 32-bit data path
 Speeds (access times): 60, 70, 80 nanoseconds (ns)
 Smaller number indicates greater speed
 Components making up the access time
 Processor requests the data
 Memory controller locates data on the SIMM
 Data is placed on the memory bus
 The processor reads the data off the bus
 Memory controller refreshes memory chip on SIMM

By FITA AYALEW

DIMM Technologies
 DIMM (dual inline memory module)
 Has independent pins on opposite sides of module
 Can have memory chips on one or two sides
 Has 168, 184, or 240 pins on edge connector
 Has a 64-bit data path and holds 8 MB - 2 GB RAM
 Synchronous DRAM (SDRAM)
 Has two notches, and uses 168 pins
 DDR (Double Data Rate) and DDR2 DIMM
 DDR SDRAM runs 2 x faster than regular SDRAM
 DDR2 SDRAM is faster than DDR, uses less power

By FITA AYALEW

Table 7-1
General approach to troubleshooting
By FITA AYALEW

Figure 7-3 Using dual channels, the memory controller can
read from two DIMMs at the same time

By FITA AYALEW

How to Upgrade Memory
 The basic technique: add more RAM modules
 Problems solved with new memory:
 Slow performance
 Applications refusing to load
 An unstable system
 Note empty memory slots on most new computers
 Accommodate new DIMM or RIMM

By FITA AYALEW

How Much and What Kind of Memory to Buy
 Questions to ask before performing an upgrade:
 How much memory do I need?
 How much RAM is currently installed in my system?
 How many memory modules are currently installed?
 What kind of memory modules are currently installed?
 How much memory can I fit on my motherboard?
 What kind of memory can I fit on my motherboard?
 How do I select and purchase the right memory?
 Refer to system utilities to determine capacity
 Motherboard documentation guides choice of add-ons

By FITA AYALEW

Installing Memory
 Follow safety procedures when installing RAM
 Example: always use a ground bracelet as you work
 Installing SIMMs
 Module slides into slot at an angle
 Make sure each module is secured to slot
 Verify that POST memory count includes new module
 Installing RIMMs
 Install modules in this order: bank 0, bank 1
 Remove the RIMM (placeholder) filling the slot
 Use notches to help orient module in the socket

By FITA AYALEW

Installing Memory (continued)
 Installing DIMMs
 Pull out the supporting arms on the sides of the slot
 Use notches on the DIMM edge connector as a guide
 Insert the DIMM straight down into the slot
 Ensure that supporting arms lock into position
 New installations are generally uncomplicated
 Usually involves just placing memory on motherboard
 Older computers may need change to CMOS setup
 If new memory not recognized, try reseating device

By FITA AYALEW

Upgrade Problems
 Dealing with unrecognized add-on or error message
 Remove and reinstall the module
 Check for the suitability of the module for the board
 Ensure that the module is the correct size
 Remove the module and check for error message
 Test the module in another socket
 Clean the module edge connectors
 Try flashing BIOS

By FITA AYALEW

Recurring Problems
 Symptoms of an unreliable memory:
 The system locks up
 Error messages about illegal operations often display
 General Protection Faults occur during normal operation
 Some troubleshooting tasks
 Run updated antivirus software to check for viruses
 Replace memory modules one at a time
 Try uninstalling the new hardware
 Test, reseat, or replace RAM
 Verify that virtual memory settings are optimized

By FITA AYALEW

Summary
 RAM categories: static RAM (SRAM), dynamic RAM
(dRAM)
 Modules used to store DRAM: SIMM, DIMM, RIMM
 Synchronous DRAM (SDRAM): moves to the beat of
the system clock
 Simple parity checks identify one corrupted bit
 Error correcting code (ECC) detects and corrects one
flipped bit

By FITA AYALEW

Summary (continued)
 Memory speeds are measured in ns, MHz, PC rating
 When upgrading memory, use the type, size, and
speed the motherboard supports
 New modules should match those already installed
 Install new modules by inserting them into the
appropriate slots
 When troubleshooting, first try the simple technique
of reseating the module

By FITA AYALEW

CHAPTER 8
Hard Drives

By FITA AYALEW

Objectives
 Learn how the organization of data on floppy drives
and hard drives is similar
 Learn about hard drive technologies
 Learn how a computer communicates with a hard
drive
 Learn how to install a hard drive
 Learn how to solve hard drive problems

By FITA AYALEW

Introduction
 Hard drive: most important secondary storage device
 Hard drive technologies have evolved rapidly
 Hard drive capacities and speeds have increased
 Interfaces with the computer have also changed
 Floppy disk will be presented before hard drives
 Floppy disk is logically organized like a hard drive
 Practical applications:
 Managing problems occurring during drive installation
 Troubleshooting hard drives after installation

By FITA AYALEW

How Hard Drives Work
 Components of a hard drive:
 One, two, or more platters (disks)
 Spindle to rotate all disks
 Magnetic coating on disk to store bits of data
 Read/write head at the top and bottom of each disk
 Actuator to move read/write head over disk surface
 Hard drive controller: chip directing read/write head
 Head (surface) of platter is not the read/write head
 Physical organization includes a cylinder
 All tracks that are the same distance from disk center

By FITA AYALEW

Figure 8-1 Inside a hard drive case

By FITA AYALEW

Tracks and Sectors on the Drive
 Tracks on older drives held the same amount of data
 Newer drives use zone bit recording
 Tracks near center have smallest number sectors/track
 Number of sectors increase as tracks grow larger
 Every sector still has 512 bytes
 Sectors identified with logical block addressing (LBA)

By FITA AYALEW

Figure 8-2 Floppy drives and older hard drives use a
constant number of sectors per track

By FITA AYALEW

Figure 8-3Zone bit recording can have more sectors
per track as the tracks get larger

By FITA AYALEW

Drive Capacity for Today’s Drives
 The OS reports the capacity of hard drives
 Accessing capacity data using Windows Explorer
 Right-click the drive letter
 Select Properties on the shortcut menu
 Calculating total capacity if drive is fully formatted
 Record capacity of each logical drive on hard drive
 Add individual capacities to calculate total capacity
 Reporting total capacity (regardless of formatting)
 Windows 2000/XP: use Disk Management
 Windows 9x: use Fdisk

By FITA AYALEW

Hard Drive Interface Standards
 Facilitate communication with the computer system
 Several standards exist:
 Several ATA standards
 SCSI
 USB
 FireWire (also called 1394)
 Fibre Channel
 The various standards will be covered

By FITA AYALEW

Figure 8-4 A PC’s hard drive subsystem using
parallel ATA

By FITA AYALEW

Figure 8-5 A hard drive subsystem using the new serial
ATA data cable

By FITA AYALEW

How to Select a Hard Drive
 Hard drive must match OS and motherboard
 BIOS uses auto detection to prepare the device
 Drive capacity and configuration are selected
 Best possible ATA standard is part of configuration
 Selected device may not supported by BIOS
 Troubleshooting tasks (if device is not recognized)
 Flash the BIOS
 Replace the controller card
 Replace the motherboard

By FITA AYALEW

Problems with Hard Drive Installations
 CMOS setup does not reflect new hard drive
 Solution: Enable autodetection and reboot system
 Error message: “ Hard drive not found.”
 Reseat the data cable and reboot the PC
 Error message: “No boot device available.”
 Insert bootable disk and restart the machine
 Error message 601 appears on the screen
 Connect the power cord to the floppy disk drive
 Error message: “Hard drive not present”
 Restore jumpers to their original state

By FITA AYALEW

Problems with Hard Drive Installations (continued)
 • Things to check if CMOS setup does not show drive
 Does your system BIOS recognize large drives?
 Is autodetection correctly configured in CMOS setup?
 Are the jumpers on the drive set correctly?
 Are the power cord and data cable connected?

By FITA AYALEW

How to Approach a Hard Drive
Problem After the Installation
 Some post-installation problems
 Corrupted data files
 A corrupted Windows installation
 A hardware issue preventing system from booting
 Preparation steps
 Start with the end user: conduct an interview
 Prioritize what you have learned
 Example: make data backup your first priority
 Be aware of available resources
 Ex amples: documentation, Internet, Technical Support
By FITA AYALEW

Hard Drive Hardware Problems
 Causes of problems present during boot:
 Hard drive subsystem
 Partition table
 File system on the drive
 Files required for the OS to boot
 Some things to do if POST reveals problem
 Check the jumper settings on the drive
 Check the cable for frayed edges or other damage
 Try booting from another media; e.g. setup CD
 Check manufacturer Web site for diagnostic software

By FITA AYALEW

Hard Drive Hardware Problems (continued)
 Bumps are bad
 A scratched surface may cause a hard drive crash
 Data may be recovered, even if drive is inaccessible
 Invalid drive or drive specification
 System BIOS cannot read partition table information
 Boot from recovery CD and check partition table
 To be covered in later chapters
 Bad sector errors
 Problem due to fading tracks and sectors
 Solution: replace the drive

By FITA AYALEW

CHAPTER 9
Installing and Supporting I/O Devices

By FITA AYALEW

Objectives
 Learn about the general approaches you need to take when
installing and supporting I/O devices
 Learn about keyboards
 Learn how to work with the mouse and other pointing
devices
 Learn about monitors and video cards and how they relate
to the system
 Learn how to use ports and expansion slots for addon
devices
 Learn how to troubleshoot I/O devices, including
keyboards, pointing devices, and video

By FITA AYALEW

Basic Principles to Support I/O Devices
 Internal devices: hard drives, CD drives, Zip drives
 External devices: keyboards, monitors, mice
 Connected using port off motherboard or expansion
card
 Fundamental principles and concepts:
 Every I/O device is controlled by software (device driver)
 Manufacturer is best guide for installation and support
 Some devices are manipulated with application software
 Problems can sometimes be solved with driver
 Learning about I/O devices is a moving target

By FITA AYALEW

The Mouse and Other Pointing Devices
 Pointing device
 Allows you to move a pointer on the screen
 Enables you to perform tasks; e.g., click a button
 Common pointing devices
 Mouse, trackball, touch pad
 Some mice are wireless and come with key pads
 Wireless connection made through a USB receiver

By FITA AYALEW

Mouse Technologies
 How the wheel mouse works
 Ball internal to mouse moves as you drag mouse
 Two rollers are turned by the movement of the ball
 Rollers represent x (horizontal) and y (vertical) position
 Each roller turns a wheel, which chops a light beam
 Chops encode movement, which is passed to CPU
 The optical mouse
 Ball replaced with microchip, laser light, and camera
 Light illumines surface and camera takes snapshots
 Microchip reports small changes to the PC

By FITA AYALEW

Mouse Technologies (continued)
 Mouse buttons or scroll wheel are programmed
 Methods used by a mouse to connect to a PC
 The round PS/2 mouse port off the motherboard
 Bus card
 A serial port
 A USB port
 Y-connection with the keyboard
 Cordless technology
 Connection methods require varying resources
 Motherboard mouse is the first choice

By FITA AYALEW

Other Pointing Devices
 Trackball
 An upside-down wheel mouse
 Move the ball on top to turn rollers
 Rollers turn a wheel sensed by a light beam
 Touch pad
 Allows you to duplicate the mouse function
 Move pointer by applying light pressure with one finger
 Depressed pad senses the x, y movement
 Buttons on the touch pad are like mouse buttons
 Use touch pads or trackballs where space is limited
 Include barcode readers, fingerprint readers, others

By FITA AYALEW

Monitors
 Monitor: the primary output device of a computer
 Video card (controller, or adapter)
 Interfaces monitor with motherboard components
 Two categories:
 CRT (cathode-ray tube)
 LCD (liquid crystal display); also called flat panel
 How a CRT monitor works:
 Filaments shoot electron beam to front of tube
 Plates direct beam to paint screen from left to right
 Control grid specifies coloring of each dot on screen
 Controls one of three electron guns (red, green, blue)
 Modified beam strikes phosphor to produce color

By FITA AYALEW

Figure 9-17 How a CRT monitor works

By FITA AYALEW

Monitors (continued)
 Comparing features of LCD and CRT monitors:
 Space: LCD requires less space than CRT monitor
 Power: LCD requires less electricity to operate
 Expense: LCD monitors are more expensive
 Refresh rate: LCD response time < CRT refresh rates
 Interlacing CRT monitors draw screen in two passes
 Dot pitch: distance between color dots
 Resolution: measures number of addressable pixels
 Example 1: XGA supports up to 1024 x 768 pixels
 Example 2: SVGA supports up to 800 x 600 pixels

By FITA AYALEW

Video Cards
 Interface between monitor and computer
 Also called graphics adapters and video boards
 Five ports for five methods of data transfer:
 RGB (red, green, blue) video using a VGA port
 DVI (Digital Visual Interface): used by LCD monitors
 Composite video: RGB mixed in the same signal
 S-Video (Super-Video): sends two signals over cable
 HDMI (High-Definition Multimedia Interface)
 Two main features: bus used and RAM supported

By FITA AYALEW

Figure 9-1 This ATI Radeon video card has three ports for
video out: DVI, S-Video, and the regular VGA port

By FITA AYALEW

Figure 9-2 Rear of computer case showing ports; only the video ports are not
coming directly off the motherboard
By FITA AYALEW

Troubleshooting Keyboards
 A few keys don’t work
 Check the Num Lock key
 The keyboard does not work at all
 Check the cabling
 Key continues to repeat after being released
 Clean the key switch with contact cleaner
 Keys produce wrong characters
 If problem is due to a bad chip, replace the keyboard
 Major spills on the keyboard
 Try rinsing keyboard in water; reinstall after it dries

By FITA AYALEW

Troubleshooting Monitors and Video Cards
 Power light (LED) does not go on; no picture
 Verify that connection is tight and PC is turned on
 Power light (LED) is on, no picture on power-up
 Check contrast, brightness or backlight adjustment
 Power light (LED) is on, wrong characters displayed
 Exchange the video or motherboard
 Monitor flickers, has wavy lines, or both
 Check the cabling and the refresh rate
 No graphics display or screen goes blank
 Replace video card or add video RAM

By FITA AYALEW

Figure 9-3 To reduce monitor flicker, increase the screen
refresh rate
By FITA AYALEW

Troubleshooting Monitors and Video
Cards (continued)
 Screen goes blank after 30 seconds
 Check configuration of power management
 Poor color display
 Exchange video cards or add more video RAM
 Picture out of focus or out of adjustment
 Check adjustment knobs or change refresh rate
 Cracking sound
 Trained technician should vacuum inside monitor
 Display settings make the screen unreadable
 Return to standard VGA settings; e.g., 640 x 480

By FITA AYALEW

Summary
 I/O (input/output) devices can be internal or external
 Basic input devices: keyboard, mouse, touch screens
 Specialty input: barcode readers, biometric devices
 Output devices: CRT monitor, LCD monitor, projector
 Video card: interfaces output device with PC system
 Port types: serial, parallel, USB, FireWire
 Serial and parallel ports are obsolescent technologies
 Current port technologies: USB 2.0 and FireWire
 All USB/FireWire devices are installed using PnP
By FITA AYALEW

CHAPTER 10
Multimedia Devices and Mass Storage

By FITA AYALEW

Objectives
 Learn about multimedia devices such as sound cards,
digital cameras, etc.
 Learn about optical storage technologies such as CD
and DVD
 Learn how certain hardware devices are used for
backups and fault tolerance
 Learn how to troubleshoot multimedia and mass
storage devices

By FITA AYALEW

Introduction
 • Multimedia capabilities of PCs:
 Text, graphics, audio, video, animation
 Some applications for multimedia:
 Videoconferencing for executives
 Tools for teaching the alphabet to four-year-olds
 Mass storage devices hold multimedia data
 Types of mass storage
 CDs, DVDs, removable drives, and tape drives

By FITA AYALEW

Multimedia on a PC
 Goal: generate output that emulates reality
 Differences between cyberspace and real space
 Sights and sounds in reality are continuous (analog)
 Computer data is binary (discrete and digital)
 Challenge: bridge world of cyberspace with reality
 Topics covered:
 CPU technologies used to process multimedia data
 Multimedia devices; e.g., sound cards, MP3 players

By FITA AYALEW

Sound Cards and Onboard Sound
 Operations performed on sound:
 Basic: recording, storing, and replaying
 Advanced: editing and mixing
 Types of ports
 Output ports: used by speakers
 Input ports: used by microphone, CD player, others
 Surround Sound: supports eight separate channels
 Sound Blaster card: standard for PC sound cards
 Use CD/DVD drive or TV tuner card to bypass CPU

By FITA AYALEW

Figure 10-1 The Sound Blaster PCI 24-bit sound card has
two internal connections and four ports
By FITA AYALEW

Digital Cameras and Flash Memory Devices
 A digital camera works like a scanner
 Scans the field of image set by the picture taker
 Translates the light signals into digital values
 Digital values can be stored, viewed, edited, printed
 TWAIN: format for transferring images to a PC
 Connections may be cabled or wireless
 Solid state device (SSD): memory based on a chip
 Examples: thumb drives and flash memory cards
 Flash memory cards are used in digital cameras

By FITA AYALEW

Digital Cameras and Flash Memory Devices (continued)
 Transferring images to your PC
 Install the software bundled with your camera
 Connect your camera to the PC
 Upload the images
 Editing or printing images once they are on the PC
 Use image-editing software; e.g., Adobe Photoshop
 Picture file formats:
 JPEG (Joint Photographic Experts Group) format
 TIFF (Tagged Image File Format)
 Connect camera to TV using the video-out port

By FITA AYALEW

Web Cameras and Microphones
 Web camera: captures digital video for use on Web
 Two meanings of Web cam:
 Digital video camera
 Web site providing live or prerecorded video broadcast
 Setting up a personal Web cam for a chat session
 Use setup CD to install software
 Plug in Web camera into a USB port
 If sound is needed, plug in speakers and microphones
 Use chat software to create a live video session

By FITA AYALEW

Figure 10-2 Instant Messenger session using a Web
camera

By FITA AYALEW

TV Tuner and Video Capture Cards
 TV tuner card: interfaces a PC with a TV
 Video capture card: saves video input to hard drive
 TV tuner/video capture card may also be a video card
 Three ways to incorporate tuner and capture features
 Embed TV tuners and TV captures in motherboard
 Fit card to fit into a PCI, PCI Express x16, or AGP slot
 Connect external device to a USB port
 NTSC (National Television Standards Committee)
 Sets standards for TV tuners and video capture cards

By FITA AYALEW

Using CDs
 CD drives are read-only or read/writable
 CD surface
 Continuous spiral of sectors of equal length
 Data stored as lands (1) or pits (0)
 Process of reading data
 Laser beam is passed over pits and lands on surface
 Drive reads bit value by amount of laser deflection
 Process of writing data
 CD imprinted (burned) with lands and pits
 Acrylic surface is added to protect the data

By FITA AYALEW

Using CDs (continued)
 CD must read data at a constant rate
 Problem: linear velocity varies over rotating disk
 Solution 1: maintain constant linear velocity (CLV)
 Slow down disk when laser is near center (200 rpm)
 Speed up disk as laser goes to outer edge (500 rpm)
 Rates given allow for transfer of 150 KBps (audio)
 Drive speed must be increased for video
 Solution 2: maintain constant angular velocity (CAV)
 Disk rotates at a constant speed
 Technology is used in hard disks

By FITA AYALEW

Using CDs (continued)
 Types of CD drives (also identifies disk)
 CD-ROM drive: read only memory
 CD-R drive: recordable CD
 CD-RW: rewritable CD
 How an optical drive interfaces with motherboard
 Using an ATA or SCSI interface
 Using external drive that plugs into port, such as USB
 Installing a CD drive
 Installed drive identified in directory by letter; e.g., D
 Four choices for installation using parallel ATA (EIDE)

By FITA AYALEW

Using DVDs
 DVD (digital video disc or digital versatile disc)
 Single-sided holds up to 8.5 GB of data (movie length)
 Double-sided disc can hold 17 GB of data
 Uses the Universal Disk Format (UDF) file system
 Distinguishing between a CD and DVD
 DVD can use top and bottom surfaces to hold data
 Second opaque layer nearly doubles disc capacity
 Audio data stored in Surround Sound
 Video data stored using MPEG-2 video compression

By FITA AYALEW

Using DVDs (continued)
 Various standards used for reading and writing
 Selection criteria for a DVD drive
 The standards supported by the drive
 Ability of drive to burn CDs
 Write-once and rewritable speeds
 Latest DVD formats: HD-DVD and Blu-ray
 Installing a DVD drive
 Follow the same procedure used for CD drives
 Cabling: power cord, EDEI data cable, audio cord
 4-pin connector for analog sound, 2-pin for digital sound

By FITA AYALEW

Table 10-1 DVD standards

By FITA AYALEW

Caring for Optical Drives and Discs
 Causes of problems:
 Dust, fingerprints, scratches, defects, electrical noise
 Drive is standing vertically
 Some precautions to follow:
 Hold the disc by the edge
 Use a soft, dry cloth to remove dust and fingerprints
 Don’t paste paper on the surface of a CD
 Don’t subject a disc to heat or leave it in direct sunlight
 Don’t make the center hole larger
 Don’t bend a disc

By FITA AYALEW

Tape Drives
 Offer inexpensive, high capacity storage
 Advice: use backup software to manage backups
 Main disadvantage: data accessed sequentially
 Makes file retrieval slow and inconvenient
 A tape drive can be internal or external
 How a tape drive interfaces with a computer
 External or internal drive can use a SCSI bus
 External or internal drive can use a USB connection
 Internal drive can use parallel or serial ATA interface
 Some tips for cleaning and care
 Keep tapes away from magnetic fields, heat, cold
 Clean drive heads as recommended by manufacturer

By FITA AYALEW

Problems with CD, CD-RW, DVD, or DVD-RW
Installation
 Check data cable and power cord connections
 For an EIDE drive, check master/slave jumper set
 Check for devices using the same port settings
 Run a virus scan program
Problems when Burning a CD
 Make sure the disk capacity has not been exceeded
 Ensure hard drive has at least 1 GB of free space
 Close other programs before you begin
 Try a different brand of CDs
 Try using a slower burn rate
By FITA AYALEW

Figure 10-3 Slow down the CD-RW write speed to
account for a slow Windows system
By FITA AYALEW

Troubleshooting Sound Problems
 Some questions to ask:
 Are the speakers turned on?
 Is the speaker volume turned up?
 Is the volume control for Windows turned up?
 Some troubleshooting tasks for installation problems
 Download new or updated drivers
 Uninstall and reinstall the sound card
 Some ways to resolve issue of games without sounds
 Update and install new drivers
 Reduce sound acceleration

By FITA AYALEW

Figure 10-4 Adjust sound hardware acceleration
By FITA AYALEW

Summary
 Multimedia devices use digital data to model reality
 Sound cards enable you to record, store, replay, and edit
sound
 Digital cameras work much like scanners
 Important image formats: JPEG and TIFF
 MPEG: set of compression standards for motion
pictures, video, and audio
 Types of optical storage technology: CDs and DVDs
 CD/DVD disk surface uses lands and pits to represent
binary data
 Other mass storage devices: tape drives, removable drives
such as Zip

By FITA AYALEW

CHAPTER 11
Securing Your PC

By FITA AYALEW

Objectives
 Learn how to secure a desktop or notebook computer
 Learn how malicious software works and how to clean
an infected system
 Topics to cover
 Methods for protecting computers and networks
 How to use several security tools
 How malicious software works
 A step-by-step plan to remove malicious software

By FITA AYALEW

Securing Your Desktop or Note book Computer
 •Reasons for providing additional security
 Protection from attacks within the network
 Attacks through security loopholes
 Exposure during travel
 A few methods for securing a computer
 Limit use of the administrator accounts
 Keep Windows updates current
 Physically protect your equipment
 Keep good backups of user data
 Destroy trash that might contain sensitive data

By FITA AYALEW

Access Control
 Authentication: identifies an individual
 Authorization: assigns privileges/rights to individuals
 Types of passwords
 Power-on passwords (configured in CMOS setup)
 Windows passwords
 Online account passwords
 Application passwords
 Some rules for creating strong passwords
 Combine upper/lower case letters, numbers, symbols
 Do not use words in any language

By FITA AYALEW

Access Control (continued)
 Controlling access to a PC using Windows
 Set a user password for the user account
 Configure user access to certain files and folders
 Overview for assigning permissions to file and folder
 Disable simple file sharing from View in Folder Options
 Open Properties window of a folder and select Sharing
 Click Permissions and select options
 Protected files and folders display authentication box

By FITA AYALEW

Limit Use of the Administrator Account
 Three common types of accounts in Windows
 Administrator
 Guest
 Limited User
 Advice for protecting the Administrator Account
 Create a Limited User account for ordinary activities
 Use Administrator account for reserved activities
 Change appearance of desktop to flag the account
 Change strong password on a regular basis

By FITA AYALEW

Use a Personal Firewall
 Firewalls are implemented in software or hardware
 Purpose of a firewall
 Prevent worms or hackers from invading your system
 Turn on Windows Firewall to protect your system
 It may be configured to allow for exceptions
 Windows Firewall is included with Service Pack 2

By FITA AYALEW

Use AV Software
 Antivirus (AV) software protects system from viruses
 Using AV software to greatest effect
 Configure software to automatically download updates
 Run AV software as a background process
 Set software to automatically scan e-mail attachments
 Virus signature: distinguishing characteristics of virus
 AV software does not always stop adware or spyware
 Use removal program for adware or spyware
 Example: Ad-Aware by Lavasoft (www.lavasoft.com)

By FITA AYALEW

Set Internet Explorer for Optimum Security
 •Some security features in Internet Explorer
 Pop-up blocker
 The ability to manage add-ons
 he ability to block scripts
 The ability to disable scripts embedded in Web pages
 The ability to set the general security level
 Medium is recommended

By FITA AYALEW

Figure 11-1 Control security settings for Internet Explorer
By FITA AYALEW

Beware of Social Engineering
 Social engineering
 Tricking people into giving out private information
 Passing unsafe programs into the network or PC
 Some techniques of social engineers
 Phishing: extracting personal data via e-mail
 Scam e-mail: offers to join phony ventures
 Virus (e-mail) hoax: clogs up e-mail systems
 A few rules for using the Internet
 Do not click links inside e-mail messages
 Investigate a Web site before downloading software

By FITA AYALEW

Beware of Social Engineering (continued)
 Two ways to debunk a hoax e-mail
 Note phrases/subjects that request mass forwarding
 Use services of security site; e.g., www.hoaxkill.com
 Scripts: code segments automating set of tasks
 Example: files with extensions .wsf and .vbs
 Malicious scripts are often hidden in e-mails
 Example: the link www.symantec.com.vbs
 Protecting against malicious scripts
 Set Windows to display file extensions
 Set Windows to first load script to Notepad

By FITA AYALEW

Dealing with Malicious Software
 Malicious software (malware or computer infestation)
 Any unwanted program intending harm to system
 Transmitted to your computer without your knowledge
 Examples of malware: viruses and worms
 Some signs of malicious messages
 Pop-up ads plague you when surfing the Web
 Strange or bizarre error messages appear
 Less memory than usual is available
 Strange graphics appear on your computer monitor
 The system cannot recognize the CD-ROM drive
 Files constantly become corrupted
 The OS boots, but cannot launch the Windows desktop
 Your antivirus software displays one or more messages

By FITA AYALEW

Here's the Nasty List
 Virus
 Program that replicates by attaching to other programs
 Infected program must execute for virus to run
 Example: boot sector program
 Protection: run AV software in the background
 Adware: produces all those unwanted pop-up ads
 Spam is junk e-mail that you do not want
 Spyware: program installing itself to spy on you
 Worm: self-replicating program that overloads network
 Browser hijacker: alters home page/browser settings
 Dialer: dials phone number without your knowledge
 Keylogger: tracks all your keystrokes
 Logic bomb: dormant code triggered by an event
 Trojan horse: disguises itself as a legitimate program

By FITA AYALEW

Here's the Nasty List (continued)
 Types of viruses
 Boot sector: virus hides in the boot sector program
 File virus: hides in executable (.exe, .com, or .sys)
 Multipartite virus: combined boot sector and file virus
 Macro virus: hides in documents of macro files
 Script virus: a virus that hides in a script
 How malware replicates and hides
 Uses various techniques to load itself into memory
 Attempts to hide from AV software
 Example: stealth virus manipulates its storage file

By FITA AYALEW

Step-by-Step Attack Plan
 Run reputable AV software
 Examples: Norton Anti-Virus and McAfee VirusScan
 Run adware or spyware removal software
 Example: Windows Defender by Microsoft
 Search out and destroy what’s left
 Respond to any startup errors
 Delete malicious files
 Purge restore points
 Clean the registry
 Root out rootkits

By FITA AYALEW

Security Tips
Backup System Files
 Use Ntbackup to back up System State and registry
 When to back up the System State
 After you have made major changes to the system
 Example: after installing a new hard drive
 Make backups a routine part of monthly maintenance
Perform a Monthly Security Maintenance Routine
 Change the administrator password
 Make sure system is being automatically updated
 Check that AV software is installed and current
By FITA AYALEW

Summary
 Protect accounts and applications with passwords
 File and folders can be configured for selective permissions
 Standard security tools: AV software, firewalls, Windows
Update
 Techniques used by social engineers: phishing, scam e-
mails, virus hoaxes
 Some events to monitor: failed logon access attempts and
network activity
 Malware: invasive programs such as viruses and worms
 If AV software cannot clean or delete malware, use other
techniques such as deleting file from directory

By FITA AYALEW

Pc maintenance

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