I re-applied thermal compound and made 100% sure that the heatsink is in contact with the processor. I also am positive that the 8 pin cpu power connector is in right, maybe its not supplying enough power? I have no real way of checking if its the PSU, becuase I don't have one strong enough right now. I also unplugged the front panel from the motherboard and used the on-board power button to make sure, but it still doesn't work. But when it does work, it shuts off after about 20 minutes or so. I checked everything that could've gotten warm, but everything is running as it should be.