Broken Computer Help

[coolkishan]

My friends AMD rig wont turn on at all. Basically he was having problems before with BSODS and windows breaking alot. SO he repaired using the disk but now the computer refuses to turn on. Its not overclocked and has a good cooler.
Mobo : Asus A8n Sli Deluxe
Processor: Amd 64 3700+
PSU: Antec True Power 2.0 550w

It used to be overclocked but then he put it back to defaults and he found out that his CPU fan was off for about a few daysish. But as it has a120mm case fan right next to it the temperatures were perfectly fine so i dont think it is this.
Also the light on the motherboard is on so im confused as to how 2 help him resolve the problem. He has tried turning it on by taking out the wires to the button and putting a 2p there to start it it still wont turn on.

Anyone any ideas???
thanks

 

[Gruntled Employee]

Do the power supply fans spin up when the power is turned on? if not replace PSU if so you likely cooked the CPU, remove the heatsink and see if the processor looks or smells like burnt electronics.

Option B) take it to a shop

Option C)buy a new system

 

[Lucio]

Light on the motherboard sounds like the CPU isn't being detected, so I'm betting that running it without the cooler has fried it. Doesn't matter about any fan being "near" it, the heat was trapped under the CPU cooler and only slowly traveling up the heatsink

 

[engiNURD]

Most of the time, a lit LED on a motherboard means that the board is getting power. What HSF was being used? There are fanless heatsinks. If the heatsink was adequate enough to run without a fan, then the CPU shouldn't be fried. If you still believe the chip is in working order, the board may not stay powered on if it detects that there is no CPU fan. Also, try another PSU.