I have a custom built pc thats giving me a lot of issues. I have a full size tower 2 dvd bays and enough space compartments to hold 6 harddrives. I have an ASUS M4A78TE-E motherboard with an amd x720 cpu with 6GB of DDR3 memory Also Have 4 1.5tb seagate harddrive. 4 80MM Case Fans Thermal Take. I have a Thermaltake SpinQ CL-P0466 Heatsink Fan w Copper Heatpipes for Socket. ATI HD 5870 Video card. The power supply pushing this beast is a Corsair Proffesional Series HX850w. Now either I have the power supply over loaded or my video card is overheating or I have a defective video card. The only reason why I think its over heating is I have 2 pci-e slots I can't find the video card at the bottom because its to big and if I did that I wouldn't be able to get to my sata ports so I had to put it on the first one. Which is right undeaneath the thermal take heatsink what I believe is happening is the hot air from the heatsink is blowing down on the back on the video card. If I look in to the cataylst setting for ati it doesn't get above 40c and I've setup manually use of the fan and bumed it up to 35% but I keep getting different problems with video. One issue I have is when playing a game sometimes the screen will flicker and cause graphic distoration ie lines complete darkness. Sometimes when I boot the system up I will see the bios screen and the it just goes black no loading sounds nothing mouse and keyboard turn off because there will be no indicator lights on either of them. Sorry this is so long but I don't want to go buy something that I don't need but I really want to get this problem fixed and start playing some mafia 2 today. Thank you for any suggestions.