Freezing computer--PLEASE HELP!

[Atroxnekros]

Hey I'm having a problem that I have been trying to fix ever since I built my computer. It's my first build and I had a few people who knew what they were doing help me with it. What happens is that my computer freezes with a sort of humming or beeping sound that just repeats the last sound played. It happens seemingly randomly, but only when the computer is under stress. My specs are as follows:

my power supply is 750w Corsair
my hard drive is 2tb samsung
my video card is Radeon HD 6870
my cpu is phenom II x4 3.4GHz
my ram is G.SKILL Ripjaws X Series 8GB
my motherboard is Asus M4A79XTD EVO AM3 AMD 790X ATX AMD
and my case has seven fans on it
windows 7 64

Here's the catch. I've run every test know to man on this thing. The tests I ran say that the memory is fine, its not the graphics cards, and nothing is over heating. That doesn't leave much. I have also run a stress test, prime95 and it always freezes on that, but only on the blend option and its always withing 20 min that it freezes. Tried it with each stick of RAM separately and it only froze faster.

At this point I'm at a complete loss. Not too much to do but buy new parts and start replacing and hope I replace the right thing. ANY help would be GREATLY appreciated. Thanks!

 

[americanbrian]

You say it's not heat, but everything points to it being heat.

I would say it is maybe a small air bubble over one of the CPU cores. It would create a small "hotspot" that may not show on the "average" temperature for your CPUS. Re-apply thermal paste to the CPU properly and report back.

 

[americanbrian]

Or even one of the Chipset chips NB/SB (although it being a phenom I think you only have a NB). Check that the heatsink is mounted on the NB properly.

Try running the PC without the sides of the case on if possible. This should greatly help ventilation and allow you to see if it helps. If it does I would suggest adding vent fans.

 

[neephius]

What he said.

 

[Atroxnekros]

Alright I'll try reapplying my thermal paste and running it with the sides off. Thanks for the replies guys.