One fine morning you might turn on your computer only to find that it is not functioning at all. In such a case, you might want to do your own repair job and get the Computer up and running again. You might even this that it is time to learn how to build a computer. There is no need to panic if you know the few simple steps to determine what exactly has gone wrong.

The key to all Computer repairs is the three step process of

1) Finding out the symptoms,
2) Diagnosing the problem; i.e., pinpointing the exact area that needs repairs and,                   
3) Actually carrying out the Repairs.

Checking the symptoms.

The first thing is to make a careful check for the following symptoms.

1) Is there any light on the monitor screen?
2) Is the power led turning on?
3) Are the indicator lights on the hard disks, the Cdroms or Dvds turning on.?
4) Is there a proper beep sound when the Computer is started?
5) Is the Numlock key functioning properly?

After writing down the symptoms, you can go to the next step -- the diagnostic step. You must not skip this step by any means, because it is perhaps the most crucial step in the Computer repairing process. If you diagnose the problem well than you might not have to repent later on, that you have made a costly mistake. For example, you would be happy that you have not taken a hasty decision to change the CPU or replace the Motherboard, when actually the problem was much less serious. Let us see how to diagnose when your Computer refuses to work.

Diagnosing and repairing.

Symptom 1 :
There is no light on the Monitor screen, but all other lights are on.

If you can hear a beep sound, the power led is turning on, as well as, the lights on the hard disks, Cdrom, Dvd’s  etc are turning on, than the problem could simply be with either your video adapter card or the monitor itself and you can be rest assured that the other devices and parts of your Computer are working well. You can easily check which one of these two is faulty by connecting another monitor. If the replacement monitor works well than the problem is definitely with your monitor, otherwise, the problem is with your video adapter card.
  

Symptom 2 :
There is no light on the Monitor screen as well as no beep sound; the power led is not turning on and leds on the hard disks, Cdroms and Dvds are also off.

In this case the problem could be with the external electrical connection to your Computer. The external power problem could easily be detected by checking whether the power cord is properly connected to the PC and whether there is power in the socket. This could be done by connecting some other device, for example, an electrical iron into the socket. If the electrical iron functions well than the problem is not with the external power supply but with the internal power supply of the PC.

By proceeding further, you can check to see whether the PC power supply fan is running. In case it is not, you might safely suspect that there is something wrong with the internal power supply. In this case, it is advisable to further check the internal power supply by disconnecting the output connectors and measuring the DC voltage supply. If there is no voltage at the various pins of the connectors it surely means that the power supply is faulty. It is best to replace the power supply pack.

Symptom 3 :    
There is no light on the Monitor screen but there is beep sound, the power leds are turning on and the hard disk leds are also turning on.

In such a case it is necessary to check what kind of beep sound you are getting. If the beep sound is continuous it simply means that there is something wrong with the internal memory of the Computer. In such a case the memory cards could be cleaned, dusted and again seated properly within its socket. If the memory is good your computer will definitely start again. Or else you can conclude that the memory cards are faulty and replace the memory cards.

Symptom 4 :    
There is no light on the Monitor screen, however, the beep sound is normal, the power leds are turning on and the hard disk leds are also turning on, but numlock key is not functioning properly.

The Num-lock key gives very good indication as to the health of your PC. If your PC is in good condition the numlock led must turn on and off properly. If the numlock key is not functioning properly , you can safely conclude that there is a problem with the internal devices or parts of the PC. In this case you will have to determine which device or part is faulty. One excellent method to use is the elimination method.

The first thing to do is to disconnect the hard disk, CD Rom, DVD, sound cards , video cards etc from the mother board. After turning on the PC in this condition, if the sound beep, the power leds and the numlock key have returned to normal than there must be something wrong with the devices and parts that you have disconnected. In such a case, start connecting the parts one by one to the PC again. If you observe that upon connecting back a particular device or part the PC starts  malfunctioning than there is definitely a problem with that device or part. Replace that device or part and check whether the PC has returned back to normal. For example, on connecting the sound card the PC starts malfunctioning, than the problem could be with your sound card, and it needs to be replaced.

Symptom 5 :    
On disconnecting the hard disks, Cdrom drives, Dvds, sound card and video card, as in above, the beep sound is still not normal and the numlock key still does not function properly.

Even on disconnecting the hard disk, Cdrom drives, Dvds, sound card and video card there is no normal beep sound or the Numlock key does not function properly, than the fault could lie with the motherboard itself or the devices or parts mounted on the motherboard. The first thing to check is whether the CPU is seated properly in its socket and CPU fan is running or not. If this is Ok try replacing the CPU with a known good one. If everything returns to normal, the fault was definitely with the CPU, otherwise it points to conclusion that the motherboard is faulty. You can confirm whether the motherboard is faulty or not by replacing a known good equivalent motherboard.

Following these simple steps as enumerated above you could easily check the symptoms and diagnose the problems of the Computer yourself. It is advisable that a systematic approach to solving the Dead PC problem can easily lead to pinpointing of the exact area of the problem. You can see how easy it is to make the computer up and running if you have mastered the above technique. Read other Articles to find out the techniques of troubleshooting other types of PC problems.