Stumped

I received 2 computers of the exact same configuration from a company a few years ago. One of them, always seemed to have small issues. Pretty fancy setup, 1000rpm hard drives in raid 0. Video in sli ect. Over time a video card, hard drive and memory were replaced in the troubled computer. I began having a semi random freeze, mostly while rendering video over 5 min in length but this freeze could happen any time. No blue screen just totally frozen. The company was generous enough to replace all internal components because we couldn’t fix it. And with a slight upgrade. So all internal components are new except hard drives and power supply. I got it back. Wiped hard drives, and installed windows 7. Same crash. Disable raid. Reinstall on single hard drive, same crash. Single stick of memory, same crash. Unplug dvd drives, same crash. I have exhausted all hard ware and software options I can think of. The one part they may not have been changes is the power supply. Can a power supply cause this? Any ideas would be appreciated.

I didn’t list components because essentially they have all been stripped and replaced. Power supply is 1000watt.

Actually a PSU can cause freezing.

I had a similar issue with freezes and initially suspect it was GPU related but after much troubleshooting the PSU was at fault. Replaced PSU, never had a problem since.