I have an interesting problem that seems to be related to my power supply. What happens is that after about 30 seconds my computer shuts down. This happens whether it is loading the OS or if it is sitting at the BIOS setup screen. My hardware is as follows: PS: Rosewill 500W RD500-5DB CPU: AMD64 3000+ AM2 Single Core MB: Abit AN52 RAM: 1GB (2x512MB) DDR2 800 Video: Nvidia 8500 GT HD: Seagate 7200.10 250GB SATA 3.0 CD: Optiarc DVD+-RW/DL AD-5540A PATA TV Capture: Haupagge PVR-150 I have tried to test the power supply itself by plugging it into an older Athlon XP system that is known to work just fine. The power supply had no problem keeping the system running for over half an hour. I also tried using the power supply from the same Athlon XP system, 300W, to power up just beyond post on the computer thats having problems and it had no problem keeping it on for over half an hour as well. Thinking it was just a fluke I tried to plug the original PS back in and it died within 1 minute. I'm not certain what the problem is but it started happening after I had used the computer to grab some files off of an old HD that someone wanted copied. At that time I had no problems and the computer ran fine for at least a day afterwards. I can only guess that the PS is the culprit but I have no easy way of testing it besides using another working computer. If anyone has an idea than I would like to hear it.

And the CPU temperature is ____ ??? "If my answers frighten you then you should cease asking scary questions" - Jules Winnfield (Samuel L. Jackson) in Pulp Fiction

The CPU might be getting overheated, and thats why the PC is shutting down. See, if there is dust on the fan or heatsink. Check for temperatures in BIOS, as Jam asked. Anupam

An overheating CPU was the first thing I checked. I cleaned out the fan and heat sink and verified that the fan was working. I then checked my BIOS only to find that it didn't give current values.

"I then checked my BIOS only to find that it didn't give current values". I think you are looking in the wrong place then. Try PC Health in the BIOS. Check the fan/s in the PSU to see if they are working. The timeline of events may just be a coincidence. If the computer ran fine using a 300W and then won't run with the Rosewill PSU I would guess the PSU is defective.