PC resets itself while loading games

[BlueMercury]

I really need some help on this, if possible: Recently I had to replace my old mobo because the original one fried. I've installed everything, drivers, etc. and my pc is resetting itself whenever I try to load a game. It runs fine for hours as long as I don't run a game. Once I do, within 60 seconds it will reset itself, with no BSOD, even if automatic restart is turned off.

What I've done so far: I've checked the temps of all items in my pc, cpu runs at around 36-41c on all cores at idle, and around 50c at the time the pc resets. GPU is low 40s at idle, and 50s at reset. My pc in the past has run hotter than this with no issues at all. Voltage on my psu seems right. I've clean installed windows, reinstalled all drivers, tried different settings, can't get it to work. I also stress tested my system, and even at 100% load, it doesn't reset. It seems to be only games so far.

Am I missing something? I'm looking for any suggestion on what I can do to fix this. Right now I'm wondering if it's a GPU problem, or a PSU problem. GPU has never had issues, and PSU seems fine, but both were in my old pc when the motherboard failed.

Specs:
Mobo: ASUS P7H55-M PRO
CPU: Intel I5 760 2.80ghz
RAM: Corsair 2x2GB 1333 DDR3
OS: Windows 7 64bit
GPU: Galaxy Nvidia GEFORCE GTX460
PSU: Thermaltake TR2 RX 850W

I do not overclock at all, and my case has 4 fans to help move air. It really doesn't seem to be a heat issue, which is what the symptoms first seemed to point to, and I'm at a loss. I'd appreciate any help.

 

[Raiddinn]

Thermaltake TR2 RX model PSUs are poster children for how bad PSUs can possibly be.

I think your PSU is destroying your other components, starting with your poor old motherboard.

Look at this review of a model in that line of PSUs

http://www.hardwaresecrets.com/article/Thermaltake-TR2-RX-750-W-Power-Supply-Review/902

In particular, look on page 7

http://www.hardwaresecrets.com/article/Thermaltake-TR2-RX-750-W-Power-Supply-Review/902/7

The PSU clearly shows FAIL FAIL FAIL FAIL written all over the chart AND the little yellow and black ripple charts below that show the worst possible results for the main 12v lines. Those yellow lines right there are what causes parts to get destroyed and the ones on that PSU are the worst that can possibly be drawn. There is no way to construct a worse chart even if you tried.

Please trash this component right away before it breaks something else.

Hopefully it isn't already too late.

Get a PSU like the one I have, an XFX 650w is made by Seasonic and is top of the line. It has beautiful charts and doesn't destroy other components as a result.

Then we can try to determine if the PSU has damaged anything else.