When I installed my new gtx750 GPU on my PC my PC suddenly froze during drivers installation after that I restarted it and then it shut down itself I tried again and then black screen appeared. So I decided to remove the GPU and clear BIOS then my PC started running normally. Today I got the same problem but before I had squares and restarted by telling me the integrated GPU model on the screen.now my PC does not boot up cause of black screen.My PSU has 22A on +3.3v, 32A on +5v,14A on +12v, 0.8A on -12v and 3.0A on +5vsb rail, combined is 430 w max