AMD Phenom 9750 Quad Core 2.40 GHz
Windows 7 Professional - 64bit
(Onboard) Nvidia GeForce 9100
Nvidia GT 430
8gb DDR2 (4x 2gb)
Computer turns off (no BSOD, just powers off) about a minute after loading windows 7 normally
Computer will run fine in safe mode, even under load, with no shutoffs
I removed the video card and re-plugged all motherboard power, running off onboard graphics
Ran Memtest with no issues on Ram
Fans run fine, and replaced the thermal paste on the CPU, so I don’t think it's overheating.
Computer will turn off while attempting to boot from Linux boot CD, even with main HDD removed
It seems to me that it has to be a hardware issue given it won’t even boot from a CD, but the fact that it runs just fine in win7 safe mode makes me doubt it could be the CPU or PSU.
It's a very old computer used only as a media device, but the puzzle of what is wrong has me stumped.