I've just recently upgraded my PC apart from the graphics card and PSU - here's my build: Asrock z170 extreme4 Skylake i5 6600k Corsair 16GB DDR4 RAM GTX 780 Having just found a stable overclock for my CPU I tried the Unigine Heaven benchmarking programme but within a few seconds of it running the power would cut off. I then unplugged my graphics card and used the on board graphics of the motherboard and hey presto there were no problems. I bought the 780 second hand coming up to about 4 years ago now. Seeing as CPU stress testers such as Prime95 produced no crashes but the GPU stress testers did, is it safe to say that my graphics card is busted? I had similar issues prior to upgrading so I don't believe its related to the new components.