Diagnosing a dead computer

[Dannnn]

Hi,

I left my computer on overnight yesterday, and this morning it had the scary text screen of death ("your computer has been shut down to prevent damage"). I should have made a note of the details, but instead just reset. The computer refused to startup - hard drive spun up, fans spinning away but no juice.

I've removed all the peripherals and cards save the graphics card, and tried a replacement power supply, but with no results. The problem must be with the video card, memory, motherboard or CPU, but how do I tell without finding spares and swapping them in and out? I don't have a speaker plugged into the motherboard, so any useful diagnostic beeps are going unheard.

It's a homebuilt system: Athlon XP2400+, Asus A7N8X, Radeon 9700, 2 GB of RAM.

Any suggestions gratefully received!

 

[jackschmittusa]

With no test parts, you have limited options. Re-seat the vid card and ram. You can try with 1 stick of ram, then the other. You can reset the bios. You can pull the mb and try it on the bench, where it will also be possible to do a good visual inspection (burn marks, swollen caps, cracks, etc.).

Everybody who is going to work on his own rig should have at least a speaker and a pci vid card.

 

[Biggerhammer]

Generally I would remove and replace everything- start with a clean empty case. Frequently some minor, unnoticable misconnection will go unnoticed. Reseating CPU and memory will probably do it if you're not interested in doing all this.

 

[Dannnn]

thanks - I'll buy a speaker and video card and take it from there. Presumably if I get no diagnostic beeps then the motherboard is dead.

 

[jackschmittusa]

You can probably get both (used, but working) from a local computer shop for less than $10us.

 

[Dannnn]

Just to let everyone know the resolution:

I installed a cheap video card and speaker and discovered the motherboard was well and truly dead. I replaced the motherboard and CPU, keeping all the other components (a small upgrade made sense - I assume the original CPU was okay but don't know for sure).

Checking the test results during the burn-in, I saw that the 3.3V line was showing an alarming 3.7V. I swapped in my spare power supply, and it's back to 3.3V.

I wonder if a failure in the power supply sent the 3.3V line high and blew the motherboard... ?