When fault finding a computer you would be well advised to follow a logical set of steps and take the proper precautions.

The precautions:

1. 1) Always wear an anti-static strap when working inside a computer, ensure it is connected to an unpainted metallic part of the computer.
2. Ensure that the computer is turned off and disconnected from the power point.
3. Ensure that the motherboard is correctly installed with sufficient mounts and that no part is shorting to the case or any other metallic parts.

The logical steps:

1. Clear CMOS then remove all cards and plugs from the motherboard except the power connection and internal speaker.
2. Turn the computer on and listen for beeps. (If none the power supply or motherboard has failed, try an new powersuply)
3. Turn the computer off and disconnect it from the power, then plug in the RAM (one stick at a time). Ensure it is seated correctly. Turn on and listen for a beep.
4. Repeat adding one card or plug at a time, ensuring all are seated correctly.

Note the beep sequence at each stage.

A properly working computer should beep once while booting, and the lights on the keyboard should flash while booting.

Clearing CMOS

Disconnect all external cables, open the box, and locate the CMOS battery.

Remove the battery for about a minute then put it back in. read more…