PC shuts off after a few minutes

[SweetGerald]

So the background is i'm building a new PC, and in preparation i took all my current parts and put them in an old case. When i powered it on it shut down when windows was loading. Then i tried again and it started up fine but shut down after 10 minutes or so. I tried just reinstalling windows on it and it shut down midway through. Tried taking out RAM sticks, sound card, seems to always power down after around 10-15 minutes. I currently have it powered on in the BIOS in the PC Health status menu to monitor the CPU temp and it's sitting around 36C and hasn't shut down going on an hour now. Any ideas what the issue could be?

Specs:
Intel Core 2 duo e8400
Gigabyte GA-P35-DS3R
MSI 8800GT

 

[Puppies04]

Im wondering if it could be an overheating CPU, sitting in the bios really isn't stressing the chip out anywhere near as much as installing windows would. Try reseating your CPU cooler if you haven't thought of that already

 

[BoomerD]

How's your PSU?

 

[SweetGerald]

bumping my old old thread.

So i got around to reseating the heatsink and i'm still having the same problem. It does seem like it's probably the CPU overheating. Is there anything i can do to test that?

 

[JWingfield]

Make sure your GPU is properly powered, I had this due to one of its two connections being weak. Plugged in different molex and all sorted. Good luck!

 

[dbcooper1]

You may have to assemble it outside the case if it's not the power supply to see if something is grounding to the motherboard, usually one of the standoffs or mount points. Also could be the power switch in the case; unplug it and start it by shorting the two pins the connector plugs in to as a diagnostic.