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Computer Repair ,Troubleshooting Tips and Tricks.

App101

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Sharing some useful info , credits to the original author.:drinks:
Troubleshooting & Repairing PCs​

The application of deductive techniques in solving computer system problems is called “troubleshooting”. Effective and efficient troubleshooting involves gathering of clues, investigation, and applying deductive reasoning needed to isolate a problem. Once the cause of a problem is known, you can follow a process of analyzing, testing, and substituting good components for each suspected bad component to find the specific part that has failed. Good deductive reasoning is used to isolate a failure to a particular group of components or chips. Then, circuit analysis is used to reduce the problem to a specific component.


The primary objective of troubleshooting is to restore to normal operation malfunctioning computer systems within reasonable time, cost, and effort.


Basic Requirements in Troubleshooting Computers:

1. Adequate background in electronics
2. Adequate background in computer systems hardware architecture and organization
3. Knowledge in computer systems hardware components and interconnection
4. Knowledge in computer systems operation
5. Knowledge in the use of test instruments and equipment
6. Knowledge in computer programming is an advantage, but not required

Skill Levels in Troubleshooting Computers

1. Peripheral level skill (the ability to locate a defective peripheral)
2. Card level skill (the ability to locate a defective card or circuit board)
3. Component level skill (The ability to locate a defective component or IC)

General Steps in Computer Troubleshooting & Repair
1. Don’t Panic
2. Observe Conditions (including visual inspection)
3. Use Your Senses
4. Clean & reset the connections & system unit
5. Retry
6. Assume a Problem
7. Use correct technical reference data
8. Symptom Analysis
9. Diagnose to a section (fault identification)
10. Localize to a stage (fault localization)
11. Isolate to a failed part (fault isolation)
12. Use correct equipment and software to aid in repair
13. Repair
14. Test and verify


CAUTION: Modifying and removing components from the circuit boards in your system may void the manufacturer’s warranties.

CAUTION: Discharge static electricity present in your body before troubleshooting or repairing any part of your computer system.

CAUTION: Uninformed repairs can cause more damage.


How to Troubleshoot a Dead Motherboard/Computer

Q. How do you troubleshoot a dead motherboard? (Orignally... I purchased an EP-MVP3G. I'M having a problem powering- up the motherboard... Do you have any suggestion?)


A. Try these steps:
• Disconnect the power cord form the power supply, be sure the power supply is set for 110 or 220 volts depending on your location and power and double check it (most have a 110/220 switch)

• Feel/look at the back of the power supply to determine if the fan is working.

• If not, trouble-shoot the power supply and replace it if necessary.

• If the fan is working, try another power supply anyway.

• Plug the computer directly into a known-good (a lamp works) power outlet

• Check to be sure you do not have a motherboard stand-off in the wrong position and shorting-out the bottom of the motherboard.

• Inspect/shake and listen for loose metallic objects (loose screws) on top of and under the motherboard and in expansion board slots

• Look carefully at the ISA and PCI slots, see if any of the contacts got bent/shorted-out. Sometimes an expansion board will dislodge one and it will be pushed into the bottom of the slot.

• Inspect the motherboard for broken or burnt components.

• Carefully inspect the motherboard for black soot from bad bearings and clean and replace the culprit.

• Look for bent/shorted pins on the motherboard headers and straighten.

• Be sure the speaker is plugged into the motherboard. If you hear beeps. Decode the beep code.

• If not, double-check all jumpers.

• Push down on all chips that have sockets in attempt to reseat them.

• What CPU are you using? Be sure the core voltage is correct.

• Be sure the CMOS battery jumper is in the correct position. Some distributors purposely ship motherboards with the jumper in the wrong position.

• Find the jumper that clears the CMOS, put it into the clear position for several minutes, put it back in the normal position, plug-in the power cord, and push the power-on button. If you apply power to the motherboard with the jumper in the clear position you may damage the motherboard.

• Pull all boards except video.

• Disconnect all cables going to all drives, pull all cables except power, power on, and speaker, connect the power supply to the motherboard (the black wires go in the middle on AT power supply connectors--"Black OK, red your dead"), reseat the memory, plug-in and screw-down the display adapter and nothing else (push down on the top, front of the adapter and make sure it is properly seated by looking at it all along the PCI or AGP connector), connect the power-on switch and the speaker.

• Check the monitor plug for bent or pushed-in pins, connect the monitor and nothing else. Check the monitor power cable.

• Reseat/replace the memory.

• Check for Motherboard Electrolytic Capacitor Failures

• Check the CPU for bent pins.

• Try another processor. Note: If you apply power to a motherboard with an Athlon or Duron processor without the CPU fan connected, even for a few seconds, you will fry it.

• Check the CMOS battery with a multi-meter. Should be around 3 volts (2.8 is ok).

• Try a different video board.

• See if the CPU and memory will work with another motherboard.

• Pull the motherboard, set it on the box it came in, install video, memory, CPU, power, and power on. See if it boots. I have seen several instances where this works when the board will not work in the case. And, when reinstalled in the case, it continues to work. I have also seen where it didn't work out of the case immediately, but did work the next day and continued to work. One of those mysteries.

• Replace the motherboard.


Processor Troubleshooting Techniques

Processors are normally very reliable. Most PC problems are with other devices, but if you suspect the processor, there are some steps you can take to troubleshoot it. The easiest thing to do is to replace the microprocessor with a known-good spare. If the problem goes away, the original processor is defective. If the problem persists, the problem is likely elsewhere.

If during the POST the processor is not identified correctly, your motherboard settings might be incorrect or your BIOS might need to be updated. Check that the motherboard is jumpered or configured correctly for your processor, and make sure you have the latest BIOS for your motherboard.

If the system seems to run erratically after it warms up, try setting the processor to a lower speed setting. If the problem goes away, the processor might be defective or overclocked.

Many hardware problems are really software problems in disguise. Be sure you have the latest BIOS for your motherboard, as well as the latest drivers for all your peripherals. Also, it helps to use the latest version of your given operating system because there usually will be fewer problems.

Troubleshooting Processor-Related Problems:

Problem:
System is dead, no cursor, no beeps, no fan.

Cause:
Power cord failure.
-Plug in or replace power cord. Power cords can fail even though they look fine.

Power supply failure.
-Replace the power supply. Use a known-good spare for testing.

Motherboard failure.
-Replace motherboard. Use a known-good spare for testing.

Memory failure.
-Remove all memory except 1 bank and retest. If the system still won't boot replace bank

Problem:
System is dead, no beeps, or locks up before POST begins.

Cause:
All components either incorrectly installed.
-Check all peripherals, especially memory and graphics adapter. Reseat all boards and socketed components.

Problem:
System beeps on startup, fan is running, no cursor on screen.

Cause:
Improperly seated or failing graphics adapter.
-Reseat or replace graphics adapter. Use known-good spare for testing.

Problem:
System powers up, fan is running, no beep or cursor.

Cause:
Processor not properly installed.
-Reseat or remove/reinstall processor and heatsink.

Problem:
Locks up during or shortly after POST.

Cause:
Poor heat dissipation.
-Check CPU heatsink/fan; replace if necessary, use one with higher capacity.
Improper voltage settings.
-Set motherboard for proper core processor voltage.
Wrong motherboard bus speed.
-Set motherboard for proper speed.
Wrong CPU clock multiplier.
-Jumper motherboard for proper clock multiplier.

Problem:
Improper CPU identification during POST.

Cause:
Old BIOS.
-Update BIOS from manufacturer.
Board not configured properly.
-Check manual and jumper board accordingly to proper bus and multiplier settings.

Problem:
System won't start after new processor is installed.

Cause:
Processor not properly installed.
-Reseat or remove/reinstall processor and heatsink.
BIOS doesn't support new processor.
-Update BIOS from system or motherboard manunew facturer.
Motherboard can't use new processor.
-Verify motherboard support.

Problem:
Operating system will not boot.

Cause:
Poor heat dissipation.
-Check CPU fan; replace if necessary; it might need a higher-capacity heatsink or heatsink/fan on the North Bridge chip.

Improper voltage settings. Wrong motherboard bus speed.
-Jumper motherboard for proper core voltage. Jumper motherboard for proper speed.

Wrong CPU clock multiplier.
-Jumper motherboard for proper clock multiplier.

Applications will not install or run.
-Improper drivers or incompatible hardware; update drivers and check for compatibility issues.

Problem:
System appears to work, but no video is displayed.

Cause:
Monitor turned off or failed.
-Check monitor and power to monitor. Replace with known-good spare for testing.


Video Card Diagnosis

Assuming the system power comes up with yor monitor. Most monitors have a status LED on the front-down-right side that should show green, orange, or blinking if the monitor is powered on. You can also hear most monitors power on with a gentle sound, though I can't be describe it beyond saying it's the sound of a CRT tube warming up. Make sure your monitor is plugged into a good outlet by testing the outlet with a lamp or any other device that will prove beyond a doubt that the outlet is good. Make sure that the power cord is either permanently attached at the monitor end or that it is seated fully in the socket, since partial cord insertion is the most common failure for monitors with detachable cords.Most new monitors will display something such as "No signal", or "Attach video signal," as long as they are healthy, and powered on. These messages should appear even if the PC or video adapter is dead. This is actually one of the more useful innovations in monitor technology, because it offers definitive proof that the computer monitor or LCD display is alive and most likely capable of displaying an image if a video signal was present. Unfortunately, it only proves something by its presence, since older monitors and cheaper models may not display anything at all.

Make sure the 15 pins video signal cable is seated squarely on the video port on the back of the video card. The hold-down screws on either side of the connector should be screwed in all the way, but dont made it up too tight. If the video cable is connected correctly, remove it and inspect the connector for damage.

Look carefully at the pins in the connector to make sure none of them are at an angle or flattened against the bottom. Note that missing pins in a video cable are the norm, usually the monitor ID pins. It's great if you have a spare video cable and a monitor with a detachable cable, but most monitors have an integrated cable (don't detach) and most people don't have a spare anyway. You will usually have to settle for visual inspection for whether the cable may have been damaged.

If you see that a pin in the connector is bent, you can try to straighten it very slowly with tweezers or fine needle nose pliers. If a pin breaks, you can buy a replacement connector and solder it on with a fine soldering iron and infinite patience. You'll also need a heat shrink gun and tubing if you want to do it right.

Video Connector Pin out

* 1-Red
* 2-Green
* 3-Blue
* 4-Monitor ID (Note: pins for ID bits often not present)
* 5-Ground
* 6-Red Return (coax shield)
* 7-Green Return (coax shield)
* 8-Blue Return (coax shield)
* 9 No-Connection
* 10-Sync Ground
* 11-Monitor ID
* 12-Monitor ID
* 13-Horizontal-Sync
* 14-Vertical-Sync
* 15-Monitor ID

If resetting the card doesn't clear up the beeps, it's either video adapter failure or RAM on the motherboard. You can power down and try resetting the RAM at this point, without going all the way through the motherboard diagnostics. There used to be beep codes for all sorts of component failures, but most of those components have long since been integrated into the motherboard and can't be replaced if they fail.

Do you get a live screen, or at least move past the BIOS screen, with all the other adapters removed or replaced? If so, the problem is either a bad adapter preventing proper operation of the bus or an adapter conflicting with the video card. In either case, you can reinstall the adapters one at a time, powering up after each one, troubleshooting the problem by process of elimination. Don't forget to unplug the system each time before taking any action inside the case.

If the motherboard is a new upgrade, try the video adapter in another system before trashing it, since it could be a simple incompatibility. If installing a new video adapter doesn't solve your "dead screen" problem, it's probably a motherboard related problem, even though you got to this point without any beep codes. Proceed to Motherboard, CPU and RAM Failure.


[align=center][align=center]PC Turn On Failure Diagnosis
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This is to determine if why the computer doesn't turn on or how you can tell if whats going on with the computer why it doesnt turn on?

First
The first step in power supply diagnostics is determining whether or not the power comes on. In the first step you can tell if your pc has an electricity supplied inside by : hearing a CPU fans turning and driver motors spinning and seeing up some light in front of the CPU case, and hear up some BIOS beeps. If the System is warm pull the plug immediately ,you might have a ground failure or a short. If u heard something thats annoying check if the power supply fan is creating a breeze. Monitors are powered independently, unless if you are looking at a notebook PC,(a live screen doesn't indicate a working power supply).

Second
If the power doesn't come on, the first thing to do is to ckeck that you have a live power source. You don't need a Volt Meter to check if your power outlet is live. Just unplug the power supply cord and plug in a lamp or a radio. If you are using a power strip, don't assume the socket you are using is good because the other outlets are working and the power strip status light is on. Many power strips in the field have at least one bad outlet, and working outlets have been known to fail for no particularly good reason. Power supply cords very rarely fail, but it's possible for the female connector on the power supply end to be back out of the socket. Make sure that both ends of the power supply cord are fully inserted in the outlet and the power supply, respectively.

Third
Make sure you are using the correct voltage is (110V/ 220V) selected on the power supply. While this should never come up with a PC that's just been sitting on the desk, if you've replaced the power supply or moved the PC, it's always possible. There is a small red slide switch located on power supply, usually between the power cord and the on/off override switch on the back of the case. Unplug the supply and select the proper voltage for your country e.g Philippines 220V. If you tried to power up with the switch set to 220V in a country using 110V, the system should be OK when you correct the voltage. If you tried running on 110V in a 220V country, you've at probably blown a fuse in the supply (at the least), or damaged the supply and possibly the other components of ur power supply.

after checking possibilities try the next

Fourth
Assuming your PC is connected to a monitor, the next question is, do you have a live screen? Do texts or a splash screen appear? A message saying "Please connect monitor" or "No video signal detected" counts as a "No" answer in this case. If the screen is live, but you see multiple images or endless scrolling, the video adapter is providing signals that cannot be interpreted by the monitor. This usually occurs when you attach an old monitor to a new PC and the monitor doesn't support the refresh rate at the screen resolution selected in the Windows settings.

Fifth
If the power supply comes on but you don't get a live screen, switch off and try again. You may have to hold the power switch in for five or more seconds before the system powers back down. If it fails to power down, you can turn off the switch on the back of the power supply, turn off your power strip, or unplug the cord. A PC that boots on the second or third try is most likely suffering from a quick power_ok (or power_good) signal, coming on before the power supply has stabilized. The presence of the power_ok signal tells the motherboard that the power supply is stable, while the absence tells you the motherboard to stay off to protect itself. It's possible the power supply isn't quite up to the current ATX standard or the motherboard is a little too demanding about the timing. Booting twice every time you want to turn on the PC isn't an ideal thing to do, so unless you leave it on all the way, look into buying a higher quality power supply, ideally power supply that are recommended by the motherboard manufacturer.


10 Things you should do when your computer hangs up!

You are in the middle of doing your work, suddenly you realized your computer hanged up. But the problem is, you have not saved your work! Don’t panic! There is a solution for that! And you can surely save your file! Here’s how:


1. Click on “ctrl-alt-delete” keys.

The windows task manager will then open, click on all programs that you don’t need and end the task. You will see that all programs on your taskbar will close one by one. If this will resolve the issue! – then save! (tip# 1: if you’re working on an MS Office application, it will automatically save your file in case the programs suddenly shut down — tip# 2: always save your file at least every 2 minutes by just simply clicking on the “diskette icon”— its just one click!)


2. If it did not resolve the issue,

are there some users logged on that computer? If so, go to switch user (for XP) and log off that user, go back to your log on screen and log on again.


The reason the computer hang up is because if there are many open programs and applications, these retains in the memory, if it is too much for the memory to handle, it freezes! Another reason too the computer hang up is because if you are connected to the internet via dial up, and you are running too many applications and opening many websites. So I suggest, if you are multimedia user or a heavy internet user, then you are better off with a higher memory, at least 512Mb of memory.


There are simple ways to avoid computer to freeze or hang up:


3. Clean your history at least once a week

>tools>internet options>clear history. I normally set my history to “0”, meaning, when I restart my computer, it doesn’t save history pages that I have visited


4. Delete all internet temporary files

>tools>internet options>delete files (do the “offline” content too!)


5. Delete cookies


(some do not do this, but I do delete cookies at least once a week!) >tools>internet options>delete cookies
6. Remove unnecessary programs that you no longer use
they are just occupying space and memory! >control panel>add/remove programs


7. Do defragmentation at least once a week

>point the mouse to “start” button, then right click “explore”>right click the mouse pointing to drive C (which is usually the main system logical drive) >properties>tools>defragment now


8. You can also check the logical drive’s volume for errors

>point the mouse to “start” button, then right click “explore”>right click the mouse pointing to drive C (I repeat, is usually the main system logical drive) >properties>tools>check now


9. It is better to have only one user being logged on.

Even if there are many users, make sure the user logs off after using the computer, rather than keeping it logged on and you do the switching of users. Switching users is good as long as you don’t keep all users logged on—I think that is more logical


10. Always shut down properly the computer

(do NOT use the power button when turning it off! )​

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For help and suggestion ,don't hesitate to post .
 

OliverE

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Wow nice guide, well im sure it would be if I had time to read it :)
Having a quick look and some of this will be usefull when building me new pc :D
Thanks a bunch :clapping:
 
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