Here are the specs for my box:
Case: Thermaltake Tsunami VA3000SWA
PSU: ePOWER ZU-650W
MB: ASUS P5N32-SLI Deluxe
CPU: Intel Pentium D 930
CPU Fan: ARCTIC COOLING Freezer 7 Pro
Memory: Patriot 2GB DDR2 SDRAM (Dual Channel)
Video: EVGA GeForce 7600GT 256MB x2 (SLI)
HD: Western Digital Caviar SE16 250GB x2 (striped)
I purchased and assembled the system in May of 2006. Everything worked fine until summer of 2007 when it started shutting down randomly. At first I thought it was overheating since removing the side panel seemed to help. But none of the components seemed to be getting too hot. The warmest area inside the box was the space between the 2 video cards so I purchased a PCI slot fan and put it in between them. This didn't seem to help at all.
So I installed PC Probe II (provided by ASUS). According to PC Probe II the system is not overheating at all. The CPU generally runs between 28C and 35C and the MB runs between 25C and 32C, which is well within the tolerance levels. PC Probe II does show a problem with the +5V. Every 10 to 15 minutes the +5V will spike up to about 5.5 volts. Usually it goes back down a few seconds later. But sometimes it stays high too long and then the machine shuts down. This seems to happen more the warmer the system is.
Additionally, if I move any of the power cables coming the from the PSU (or even touch them) while the system is on it immediately shuts down.
I figure it's a problem with the PSU. Either it's going bad or there is a short/bad connection somewhere which get worse as it heats up and expands. But I don't have another PSU handy to make sure. So, before I bought a new one I thought I'd see if I could get more info from the net.
Thank you for any info you can provide, even if just to confirm my suspicions about the PSU.