PC Repair Fundamentals

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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 what happens when you first turn on a PC before the OS

is loaded• Learn how to approach and solve a PC problem• Learn how to troubleshoot a failed boot before the OS is

loaded

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Introduction• Basic repair skills

– Developing a maintenance plan– Implementing a maintenance plan– Working inside a computer case– Following sequence of events that occur at startup

• Advanced repair skills– Using common-sense guidelines to solve problems– Interviewing a user– Determining if a problem occurs before or after boot– Troubleshooting and solving a problem of a failed boot

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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

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Figure 2-1 PC support technician tools

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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

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Figure 2-2 Windows Setup CD and Windows Recovery CDs for a notebook computer

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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

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Figure 2-3 Loop-back plugs used to test serial and parallel ports

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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)

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Figure 2-5 Each chemical you use should have available a material safety data sheet

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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.

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Figure 2-6 Post Code Master diagnostic card by MSD, Inc.

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PC 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

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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

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Figure 2-9 Configure antivirus software to scan e-mail and instant message attachments and to download updates automatically

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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

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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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Preparing a Computer for Shipping• Adverse factors to consider:

– Rough handling– Exposure to water, heat, and cold– Misplacement or theft of computer

• Some shipping guidelines to follow:– Backup the hard drive onto a backup medium– Remove inserted disks, tape cartridges, or CDs – Coil and secure all external cords – Separately wrap hardware components – Purchase insurance on the shipment

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Disposing of Used Equipment• Various guidelines for disposing of equipment:

– Table 2-2– Manufacturer documentation– Local environmental regulators

• Danger posed by monitors and power supplies– Residual charge in capacitors can cause shock– Modern devices discharge if unplugged for 60 minutes– Older devices may require discharge with a probe

• Destroy secondary storage devices with sensitive data

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Table 2-2 Computer parts and how to dispose of them

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How to Work Inside a Computer• 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

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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

• If working inside a monitor, do not ground yourself

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Figure 2-13 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

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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 2-19 Removing the cover

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Steps to Take Apart a Computer• 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 2-33 Remove the motherboard from the case

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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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Understanding the Boot Process• Key learning objectives

– Know how to boot a PC– Understand what happens first when a PC is turned

on– Understand how an operating system is loaded

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Booting a Computer• Process that drives a computer to a working

state• Hard (cold) boot: turn the power switch on • Soft (warm) boot: allow the OS to reboot• How to soft boot Windows XP

– Click Start– Click Turn Off Computer– Click Restart

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Hard Boot and a Soft Boot• Hard boots are more stressful on machines

– Power surges through system when PC is turned on• Reasons to choose a soft boot over hard boot

– Less stressful on the machine – Faster due to skipping initial steps

• Some computers have a soft and hard power switch– Soft power switch shuts down and restarts Windows– Hard power switch cuts power and restarts machine

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BIOS Controls & Beginning of the Boot

• The startup BIOS gets a system up and running• Four phases of the boot process:

– BIOS runs the POST and assigns system resources• POST: power-on self test

– BIOS searches for and loads an OS– OS configures system and completes its own

loading– Application software is loaded and executed

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Figure 2-40 Boot Step 1: The ROM BIOS startup program surveys hardware resources and needs and assigns system resources to satisfy those needs

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Changing the Boot Sequence• BIOS looks to CMOS RAM to locate the OS • Boot sequence: order of drives checked for an

OS• Change boot sequence using CMOS setup

utilities• Access CMOS setup utilities when PC is turned

on– Example: press F8 before Windows screen appears

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Figure 2-42 Numbered steps show how BIOS searches for and begins to load an operating system (in this example, Windows NT/2000/XP is the OS)

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How to Troubleshoot a PC Problem• Assume the attitude of an investigator• Do not compound the problem by your own

actions• Look at the problem as a learning opportunity• Ask questions until you understand the

problem• Believe that you can solve the problem

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Steps to Solving a PC Problem• Key advice:

– Ask good questions – Document the process

• Four-step problem solving process:– Step 1: Interview the user– Step 2: Back up data– Step 3: Solve the problem– Step 4: Verify the fix and document the solution

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Figure 2-44 General approach to troubleshooting

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Troubleshooting a Failed Boot• It takes time to acquire troubleshooting skills• Hands-on training: troubleshooting a failed

boot

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My Computer Won’t Boot• First step: maintain your calm• Second step: develop a game plan• Figure 2-45 provides a procedure • Plan is driven by a set of yes-no questionsExample: Does the

PC boot properly?• If no, troubleshooter is directed to another question• If yes, troubleshooter is directed to stop (for now)

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Figure 2-45 Use this flowchart when first facing a computer problem

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Major Subsystems Used For Booting• Categories of troubleshooting steps in Figure

2-45– The electrical subsystem– Essential hardware devices

• The motherboard, memory, and the CPU

– Video – Reading from the hard drive

• Key aides: tables identifying error codes

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Table 2-4 Beep codes and their meanings

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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

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Summary• Assembling and reassembling a PC prepares the

technician for actual repair work• Startup BIOS controls when the boot process begins • Four step boot process: POST, loading the OS, OS

initializing itself, loading and executing applications• Expert troubleshooters ask good questions• Before tackling a problem, develop a game plan