Computer broke out of nowhere

[randomness]

My brother was playing warcarft 3 and suddenly the computer switched off.

It went off with a small bang [not an explosion] - no smoke or broken components.

He is running a 3 year old computer, when i touched the heatsink, it was very hot maybe ~80C and burns my skin. [Pentium 4 3.2GHZ socket 478]

When i was diagnosing the problem, i unplugged everything except the ATX12V and ATX 20pin with RAM,heatsink and graphics card in.

I press the power switch, the cpu fan spins momentarily, [around 0.1 seconds] and stops. The power supply is working and i even tried plugging in my old power suply with no luck

So, i unplugged the ATX12V connector and it turned on, but it did not boot up[lack of voltage to components]. w/o everything else plugged in, im assuming the problem lies with the motherboard, [maybe the circutry for the ATX12V is broken??]

PLease help me with this, i dont like sharing my comp with other people!

[Kheldar]

I'd say the PSU has bit the dust
sometimes they still power some things

some other componets may have gone as well

[randomness]

Ive tested it with my old working power suply and it still doesnt work.

Ive checked for popped capacitors and they are all fine.

[Kheldar]

try a bios reset - power surge could have scrambled it - remove battery & power, and short jumper and reinstall battery & power

[ANZAC_ELITE]

...... i even tried plugging in my old power suply with no luck ........

This and the heat you mentioned are not good signs, reset the cmos, remove the ram and video card then boot with your old psu, if you get no beeps then the m/board/cpu is probably toast. (check cpu/ram pins for signs of charring)

If you do get beeps (note what they are and look in the manual/online to verify their meaning) then add one stick of ram, reboot, if the board and ram is good you should get the beep code for no vga, if that happens then inset vga, reboot.

The fact that the heatsink was hot enough to burn you when you touched it would suggest to me the cpu has over heated (theoretically it should have shut itself down, Intel thermal protection, given the cpu specs you posted I'd hazard a guess that it is a Northwood) if this hasn't occured then the chances are fairly good the either the cpu or board or both are fried. Is there any way you can test the components (cpu/ram) in another pc?

[randomness]

Yeh i can test the RAM and thats about it. No socket 478 mtherboards and no AGP slot.

K im testing it now.

[randomness]

I have tried the 512MB DDR400 on my computer, and it works.

Ive also resetted the CMOS with the jumper abd reseated the battery.

Oh it is a gigabyte motherboard, i should go to the gigabyte forum and ask there Doh

Still not working, i think the cpu may be dead.

[ANZAC_ELITE]

Unfortunately you have very limited options with no 478 boards available to test the cpu, do you have a PC store nearby that might be able to test it and/or the board for you?

Have a look for your purchase receipt, if the board is still under warranty RMA it, they'll test it for you. (I'm not certain that Gigabyte has a three year warranty??? I have no idea as I use Asus boards which have a 3 year warranty)