Thanks in advance for your time.
Built my own computer with some help/some new/some used parts - all good for 4 months. Had a power outage (was protected by surge - but the surge ability was ruined on the protector afterwards), that night started experiencing regular "freezes" where after so much time certain programs would start to permanently not respond. However, if I was running a voicechat program at the same time, that was still functional and operating for a while. After a while the whole computer would freeze up, and I would either manually restart, or - if I left my computer alone for long enough - it would blue screen with STOP error messages. Similarly, if I had no programs running and let it idle, it would usually react when I sat down but almost immediately programs would become non-responsive and blue screen soon enough. Now, the system is typically stable for 20-40 minutes then it has the same "slow freeze up" followed by a blue screen if I don't just restart. Same exact problem for almost 2 weeks now.
Steps I took:
1) Considering the randomness of the problem, thought I had bad RAM - memtest86'd old RAM (2x 4GB Ripjaws sticks) alone (1hr) and together (2 hrs) in various slots - no errors. Bought new RAM anyway - memtest86'd only new RAM together 60 min no errors.
Decided it wasn't RAM! Thought maybe RAM slot, CPU, MOBO or PSU damage.
2) Stress tested PSU with OCCT - blue screen after so much time. Stress tested CPU with Prime95 - blend = crashes, small FFTs = crashes (within 60 minutes - I would typically go afk) felt like I couldn't decide if it was PSU or CPU.
3) Eliminated overheating concerns - core temp's were normal, no dust build up or bad fans (5 of them).
5) Eliminated overclocking - reset BIOS to optimized defaults, then to factory defaults - same issues
4) Stress tested GPU with Furmark - 60 minutes no crash, just did again today though and blue screen.
6) Eliminated software - clean reinstall windows (twice) - same crashes
7) Visually inspected MOBO - didn't see any blown or leaking parts
8) Decided that considering the power outage, it was probably the PSU getting intermittent voltage or something. Ordered new PSU - same problems after installing today.
It doesn't matter how much stress the computer is under - IE I can run graphics intensive video games and browser windows for 20 minutes no problem then freeze, the crash just seems rather intermittent and random. I just feel like I can't narrow it down to the bad hardware. After installing a new PSU today I thought mechanically everything looks connected correctly.
Two weeks later at this point I'm at a loss - I feel like I've eliminated BIOS mistakes, software problems, virus problems, PSU, RAM - I either have a damaged CPU, damaged MOBO, or damaged graphics card. Any ideas on what to try that can narrow it down before I really lose my cool and order brand new everything?
SSD 100GB + old HD 1000GB
Intel Core i5 CPU 3.30GHZ
Gigabyte Z68X-UD3 Intel MOBO
2 x 4GB DDR3 RAM
GeForce GTX 580 GPU
850 Corsair PSU
Edited by Sinistra03, 07 June 2013 - 07:22 PM.