Baffling Power-off

[dmdrummond]

I've had this problem for a while. It resurfaced recently after installing Fedora Core 6.

Basically the machine seems to randomly power-off. No warning, nothing. Just switches off. I have ran memtest86, no problems there. The power supply is generating enough, the voltages all seem okay. It seems to happen at random, there is no associated process, or action which causes it. Motherboard temps seem okay.

THe system is:

AMD Athlon64 3700
2 x 512mb Corsair Value RAM
ECS KN1 Extreme motherboard (with nforce4 chipset)
480w Hiper psu

Times it has happened:

It used to happen a lot while running Gentoo linux, so at first I thought that perhaps I had "overoptimised" the OS. However it does periodically happen while in Windows XP. It was happening every time I booted Fedora COre 6 from Grub. It didn't even get to load the kernel, just switched off. It most recently happened while updating packages in Fedora.

It isn't made worse when I am running intensive programs such as games. I just can't figure this one out.

Does anyone have any ideas?

 

[Raze664]

You checked for loose cables from the PSU, could be a faulty PSU.

 

[dmdrummond]

Checked the power cables, they are all seated fine. Just installed Solaris, which also boots from grub, and it switches off at exactly the same time, and in exactly the same way. I really have no idea what could be causing this. Any more suggestions?

 

[networkgeek]

ouch. I hate to say this. but I experienced something a lot like this on a server at work. it was the motherboard going bad that did it.

the motherboard is required to complete the circuit with the psu when you press the power switch. sometimes a bad motherboard will break that circuit and cause the computer to power off or restart.

only solution is mobo replacement.

you already tested memory which was good

have you checked the hdd with a diagnostic yet?
google drive fitness test if you need a program

but based on what you said happens in your post, I still think it is probably the motherboard. most likely the software is making calls to a part of the board that is bad. it shorts and cuts power.