Need help diagnosing cause of freezes

Jaydent1

Honorable
May 26, 2013
2
0
10,510
The problem is as follows, my computer freezes approximately 10-15 minutes after I turn it on. It started doing this when I turned it on this morning, and has consistently crashed in this manner about 5-6 times. There is no BSOD, just a complete freeze rendering the computer unusable (keyboard/mouse not responsive). It will also crash at the Windows login screen if left idle for 10-15 minutes. At the time of the crash CPU temp was roughly 40c on idle, with GPU temp at 50c idle.

I've had this computer for about 3 years and it was built by me. The hardware hasn't been changed since then, thus I can't see it being a driver problem, as its been working perfectly fine for the past several years with the occasional GPU driver update. No recent hardware/software /driver changes to think of.

Hardware:

GTX 780
i5 3570k 3.6ghz
Corsair CPU watercooler
8gb RAM
Asrock z77 EXTREME Z4 motherboard
Corsair GS700 power supply
1tb Seagate drive

So basically I want to know what steps I should take to isolate the problem. I don't particularly have access to replacement parts to test, and I only have a limited time 10-15 minutes to snoop around before it crashes every time. I get the feeling the power supply simply isn't working properly anymore, and I am hoping it isn't the graphics card, as that will be expensive as hell to replace.