Hi, folks,

I wonder if anyone has any suggestions...

My desktop PC reboots by itself after running a while. First, it's almost 2 weeks, then, a few days, and the intervals between spontaneous re-boots gets smaller and smaller until the PC is no longer usable.

Any suggestions, please.

P.S. I ruled out the video card and driver, and I took out 1 memory bank (there are 2) and then the other, but problem persists. I'm also using new hard disks and I re-installed Windows XP, but to no avail.

TIA, Chuck

This behavior can be heat related - dust out the processor fan and heatsink assembly, thoroughly clean all fans and sinks, and note if the power supply fan is turning. The next likely candidate is failure of the power supply/power supply fan, and then the motherboard itself, however any bad device could cause this behavior.

If you boot the computer to a BIOS setup screen or a Windows boot option menu and leave it sit, does it still reboot after a fashion with no load on it?

Hi, Scleros,

Thanks so much for your reply. All fans are turning, and the dust isn't too bad. Could the power supply cause this, even though the power supply fan is turning?

TIA, Chuck

Could the power supply cause this, even though the power supply fan is turning?

Yes, one type of failure mode for electronics is components going out of spec once they warm up or get loaded. Modern power supplies output a PWR_OK signal (Intel Power Supply Design Guide for Desktop Platform Form Factors, Revision 1.1, Section 3.3.1 (http://www.formfactors.org/developer%5Cspecs%5CPSU_DG_rev_1_1.pdf)) that must be present to boot the computer and remain present during the operation of the computer. Any hiccup in the signal during operation will in conjunction with the motherboard cause a processor reset. It is hard to observe and confirm such behavior in practice without hooking the power supply up to a scope. However, swapping the power supply for a known good one, or investing in a low cost power supply tester is usually sufficient for identifying if the power supply is causing the problem. Three to five years is a common time-frame for failure. How old is your computer?

The computer is four or five years old.
I can definitely get a new power supply (and then give it back if the problem persists.)

Thanks.

Chuck

Windows XP Shut Down and Automatic Reboot Problems (http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/russel_02may13.mspx)

Please chk this link might be helpful

Thanks, zahiriyar,

It's a very interesting article. Boy these computer are complicated!

Chuck

Heyya I don't know if you solved your reboot problem... and these are some very interesting answers you have gotten... but they failed to as a simple question...
Did you build this PC yourself?
The reson I ask is because sometimes vustom built pc's.. the motherboard is touching the case causing a small short... you will need riser screws to raise you mb...
If your problem still persisted before I wrote this... try it...
If not I hope it works

Hi, ijustwannaknow,

No, I did not build it myself. The computer is much better since I got rid of the dust on the CPU heatsink (which was hidden by the CPU fan, however, it sometimes re-boots as it is booting up. Weird.

Chuck