strange shutdown issue

[tcraig_4096]

Problem: The PC "randomly" shuts itself off. The powersupply switch must be toggled before it will reboot. The shutdown has occurred under load, under idle, and duriing boot up. It appears to be random. It can run for hours or sometimes seconds before it shuts down. The PC is very well air cooled with case open.

Specs:
Coolermaster 550 watt PS
3.4Ghz Prescott with thermalright copper hs & 92mm fan
2gb pc3200 corsair
2 80mm case fans
2 HD
2 Optical drives
PCIE 6800gt
Sound Card

I have the 12v rails distributed as evenly as I can amongst components. The video card is not sharing power on it's rail. Nothing seems to get overly warm.

Does this sound like a PSU, Motherboard, or Power problem? It is seemingly random and I can not figure wtf it does this.

 

[Team Obi Juan]

Disconnect stuff and try it. I've had the same error from hard drives... Disconnect what's not necessary, and see if you can duplicate the problem.

 

[pointer]

I just went through this on a new build with a Seasonic S12 600 watt PSU.
The System ran fine for the first day, then it started with random reboots, and then I started getting a message at boot that the CPU was not working or had changed.

It turned out that the 24pin 12 volt line was running 10.5v to 11.5v, and the 12v 4 pin line was at 9.5v to 11.5v.

I changed out the PSU and I have not had a problem since.

 

[tcraig_4096]

This system has ran ok for over 18 months (With the replacement of powersupply part way through). Is it possible with some crummy power to the house that a powersupply could slowly degrade over time? It seems like a similar problem killed our old PC too.