Unit v TROUBLE SHOOTING PC

By M.Abdul

ROOM PREPARATION AND POWER SUPPLY

* ROOM PREPARATION IS VERY IMPORTANT FOR MAINTAIN THE COMPUTER .

* LOCATIONS :

* THE ROOM SHOULD HAVE ENOUGH SPACE FOR ALL THE USERS .

* THE NUMBER OF ENTRANCES SHOULD BE LIMITED.

* THE ROOM SHOULD BE AWAY FROM SMOKE OR OTHER POLLUTANTS .

* THE ROOM SHOULD AWAY FROM RADIO FREQUENCY OR ANY RADIO SIGNALS .

* THE ROOM SHOULD BE NEAR BY POWER DISTRIBUTION POINTS .

* THE ROOM SHOULD BE PROVIDED WITH PROPER TELEPHONE CONNECTION FOR CONNECTING MODEMS .

POLLUTION

* POLLUTANTS LIKE DIRT , SMOKE , DUST ETC ,, ARE NOT GOOD FOR SYSTEMS :

PRECAUTION :* CHAPPELS AND SHOES ARE NOT ALLOWED

INSIDE THE COMPUTER ROOM. * USE VACUUM CLEANERS FOR CLEANING

THE THE FLOOR. * ALWAYS KEEP THE DOORS OF COMPUTER

ROOM IS CLOSED * DON’T ALLOW PEOPLE TO DRINK , EAT OR

SMOKE CIGARETTE INSIDE THE COMPUTER ROOM * DON’T ALLOW LADIES WITH FLOWERS

ON THEIR HAIR .

AIR CONDITIONING :

* HEAT AND MOISTURE ARE THE TWO WORST ENEMIES OF COMPUTERS

. * TEMP - 20 TO 25% .

* HUMIDITY - 40 TO 60% .

* This means , the room walls exposed to direct sunlight increases the capacity of the ac machine *

POWER SUPPLY

* Power supplies are very important for maintain pc’s. Small problem make the major problems .*

* dirty power enters into the system .* it lost the data and hardware

components will be distroyed

PROBLEM DESCRIPTION POSSIBLE CONSEQUENCES

surges Sudden temporaryIncreases in voltage.

Serious damage or destuction of equipments.

sags Sudden temporary reduction in voltage

Loss of data and/or abnormal termination of program

Brownout Prolonged reduction in voltage

Overheading of components and it will decrease the components life .

Blackout Complete loss of power

Complete loss of system until power is restored. This causes the loss of data currently running on the system.

Voltage regulators *

* Voltage regulators are electronic or electromagnetical instruments

* solid state voltage regulators

* ferro resonant transformer regulators

pcb

*Pcb means printed circut borad its small electronic components in electornic circuit boards.

* solid state voltage regulators

* ferro resonant transformer regulators

* Servo stabilizer *

CONSTRUCTION OF STABILIZER

WORKING PRICIPLE OF STABiLIZER

Uninterrupted power supply (ups)

* Uninterrupted power supply are used to provide continuos power to the computer *

* off line ups

* on line ups

* off line ups *

Disadvantages

* on line ups *

advantages

Surge suppressor and spike isolators

Installation practice

FDD JUMPER FOR DRIVE SELECT *

FDD cable twist *

FDD terminator *

* Memory jumpers

* Cable connection orientation

*processor heat sink/colling fan

Preventive maintenanceParts Type of maintenance

1. Floppy disk drive

2. Tape cartridge

3. Printer

4. Mouse

5. Keyboard

6. Mother Board

Head cleaning, speed checking.

Head cleaning and Alignment

Cleaning and oiling

Cleaning the optic lens .

Use vaccum cleaners to clean the dust

Change CMOS battery once in two years and dusting

* Cotton swab

* Isoprophyl alcohol

* Vaccum cleaners

* Head cleaning disk

* Cleaning solution.

* Tape drive head cleaning cartridge

Problem cause

* Following * * dust * High temp * Electrical noise and

interference * Magnetic fields * corrosoin * power fluctuations * improper handling

PROBLEM EFFECT PREVENTIVE MAINTENANCE

1. dust Head crash in hard disk and cd drive, blocks the cooling fan and damages the processor’s .

Regular cleaning of the system and the room .

2.High temperature Data loss , electronic components and circuits failure

Provide a/c

3.Electrical noise and interference

Causes malfunctioning of circuits

Isolate the system current from other loads and use filters

4.Corrosion Affects the stored data in magnetic medium such as floppy and hard disk

Keep the system current away from magnetic devices such as TV etc

5.Magnetic fields Affects PCB and the PCB edge contacts

Control the humidity

6.Power fluctuations Data loss , damage of switch in the keyboard

Use stablizers and , ups , filters

PROBLEM EFFECT PREVENTIVE MAINTENANCE

7. Improper handling Data loss, damage of switches in the keyborad etc

Use the keyboard gently , always keep the CD and DVD inside the Covers

peripherals* A peripheral is a device attached to

a computer *

* keyborad

* printer

* Keyborad preventive maintenance *

* do not apply force on the keys

* do not rest the hands on board

* do not keep anything on the board

* do not spill liquids

* use vaccum cleaners

*printer preventive maintenance *

* Do not place the printers near the heat machines

* Clean the outer cover using domestic cleaning liquids

* Clean the inner parts using domestic cleaning liquids

* Use quality ribbons and toners

*General precautions*

* Before switch off the mains switch off the monitors

* Unscrew the screws and remove the cables before removing the ciruits boards or pheripherals

* switch off the system before removing a pcb or removing cables

* Remove the CD and dvd from drive before shutdown

* do not allow to eat or drink near the systems

* do not smoke near the system

* Always use dust covers when not used

* Store cd, floppy disketts in a clean and cool place

* place the system in max air circulation area or in an air conditition room

* clean the cooling fans window regularly

* Do not bend or scratch the cd

*do not switch off the system when the active red led is glow

* clean the cooling fans window regularly

* Do not bend or scratch the cd

*do not switch off the system when the active red led is glow

Fault elimination process

* Two parts *

* finding correct fault * eliminating the fault

* finding correct fault is a technique ./ sometimes a simple problem takes much time for identification . Some faults can be found by checking the various components , voltage pins / cables / earthing / jumper settings , switches position etc ,

General faults in systems

* Dead system * Spurious problem * Security failures * Heart beats * Multiple faults

* Dead system *

* It is very easy to confirm whether a system is dead or alive

* Normally it is simple to give lifi to a dead system than rectifiying a sick system

* dc voltage is absent * the clk signal is absent * firmware is corrupted * rom output is inactive

* Microproccesor is fault or dead * The ac fuse is blown

* Spurious problem *

* Spurious problem are nothing but hidden problems that are very hard to find *

* Finding these problem needs careful observation *

* the dc voltage has excessive ripples

* dc voltage is noisy

* Security failures *

* Heart beats *

* Multiple faults *

Systematic trouble shooting

* Symptoms observation * Symptoms analysis* Fault diagnosis * Fault rectification

* Symptoms observation *

* Symptoms analysis *

* Fault diagnosis *

* Fault rectification *

Diagnostic software and viruses

* Computer viruses *

Virus feel act

Precaution to ba taken to avoid viruses

Anti virus softwares

* norton *

* Norton is an antivirus softwares. It is used to protect the computer resource from known viruses

* with help of thsis we can detect the malwares and detect and clean the known viruses

* since new viruses are evolving every day

* the norton number of version in softwares

* updates *

* The latest version suports all type of softwares *

* norton antivirus 2000 * norton antivirus 2001 * norton antivirus 2002 * norton antivirus 2003

* symantec norton antivirus 2004 outdated

* Features *

* Automatically removes viruses, worms and trojan horses

* Scans and clean both incoming and outgoing e mail messages

* Detects and blocks viruses in instant messages attachments

* Downloads new virus updates automatically

* Worm blocking

Identify the signature of virus

* Firewalls *

Packet filtering gateway

Ip packet screening routers

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THANK YOU