Hi,
My PC has this problem that it shuts down sometimes on a high load I'm not sure what's the problem. I have tried switching the CPU so I suspect that its not from the CPU. The hardware specs are noted down below.
Motherboard: Asus M5A78L/ USB3 760G Am3+
Processor: AMD FX-8150 @ Stock speed
RAM Memory: 16GB of Corsair Vengeance, 1600Mhz
Graphics Card: AMD HD 7770
Power Supply: Cooler Master GX 550 W
PS. this system is used on CPU intensive programs like rendering.