Came downstairs this morning, and my wife's new comptuer i built her about a month ago was off. Tried turning it back on, no dice, reset power strip and supply, waited 2 minutes, system powered on for about 30 seconds. Following this procedure, i'm able to power it on for about 30 seconds at a time, but not keep the system on. Went to BIOS, checked settings, and looked at HW monitor, getting correct voltages, all settings are ok, except (and i never looked before0 FSB is at 533 instead of 800. I have an intel 2.4 (800 FSB) with ASUS P4S8X-MX Socket 478, geforce4200 vid, IDE 7200 80 GB HD

After 30 seconds it completely powers off?

If you don't go into the BIOS setup does Windows try to load?

Do you have another PSU to try?

completely turns off, windows will load, but it still shuts off, not especially, though the values displaying on the rails are showing correctly, of course until it turns off but then i do have to unplug, reset power strip to get it to turn back on again....

As a first test I would try a different Power Supply Unit.

I guess first of all you could go directly into the outlet. No strips or any GFI's.

same thing, no change..

You changed the Power Supply Unit?

that i have not done, as i do not have a spare one lying about....

That would be my first suspect.

In the meantime:

You could try stripping the motherboard down to CPU & Grapics & 1 stick of RAM.

See if that will stay on.