Hello i just bought a i7-3770s quad on 3.1ghz, asrock b75 pro3 motherboard, 4gb ram 1600mhz, 5400rpm 500gb hard + gtx650 2gb ti video, 650w. Everything started after i installed windows, after i log in my profile few mins later my pc shut itself down. Then i thought i try without the videocard and it worked ok with the onboard Intel® HD Graphics 4000 card. After that i installed Diablo3 to try and test the pc. Its frame rate was really bad so i thought if i use another 650w supply maybe things will be different. At first it was it worked 10 min but the d3 was still running poorly and after 10 min it shut itself down again. I currently use the pc without the video on friday i get new power supply with 750w. I hope that fixes the problem with pc shutting off but the thing that is strange for me is that a friend of mine played diablo3 on his i5 3rd gen and onboard video without much problems and i get really bad framerates even on WarCraft3 and that is a 10 years old game. What could be the issue i have no clue. I really hope the powersupply fixes all the problems because i can't afford much more than what i have already did spend.
I am going to guess that your PSU isnt providing any where close to its listed wattage. I would guess that with processor and video card that you have listed you would be looking at a real wattage need of around 350w and if you were to pull the video card you would see this drop to maybe 200w. I would see if I could borrow a PSU from someone else and test your system with that PSU. This should narrow down the problem to being the video card or the PSU.
I currently use only the HD4000 because the pc turns off when im with the gt650. I now see that my cpu temperature is 100C i think it is possible those retards at the firm maybe forgot to put paste on my processor.