Ok, so, I have a problem. Almost every time my gpu starts to run hard my computer shuts off. Either when I stress test it or when I start playing games it shuts off, no noise, no warning, nothing, just *blip* like someone unplugged it and won't come back on unless I cut the power somehow for about 10 seconds or more, either by flipping the switch on the psu or unplugging it. When it doesn't shut off immediately, and it does about 90% of the time, it will after a few minutes to an hour of playing. I've checked drivers, I've ran the cpu through Furmark's cpu burner (Nothing happened beyond what's normally supposed to), I've left the case open and stuck a shop fan in, turned it on high, and watched the temps on HWMonitor (It still shut off, and the few times it didn't immediately the temps hovered at 60 degrees when under heavy load), I've cleaned it thoroughly, even reapplied thermal paste. At this point, I don't know what to do except for replacing my gpu and psu. I haven't replaced anything and I haven't had this problem until recently. Any help would be appreciated at this point.
Specs
Motherboard: 760GM-P34(FX) (MS-7641) 4.0
Processor: 3.50 gigahertz AMD FX-8320 Eight-Core
Graphics Card: AMD Radeon HD 7700 Series
Ram: 2 4gb sticks, I can't find anything specific other than that.
Hard Drive: TOSHIBA DT01ACA200 2TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5
Power Supply: 350W Thermaltake Purepower Model: PP-350NL1NC-A
Specs
Motherboard: 760GM-P34(FX) (MS-7641) 4.0
Processor: 3.50 gigahertz AMD FX-8320 Eight-Core
Graphics Card: AMD Radeon HD 7700 Series
Ram: 2 4gb sticks, I can't find anything specific other than that.
Hard Drive: TOSHIBA DT01ACA200 2TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5
Power Supply: 350W Thermaltake Purepower Model: PP-350NL1NC-A