I built my PC and after a year it suddenly turned off after lagging for a while in a game. It turned back on for a while and then turned off again. When I turned it back on it wouldn't give me display or power to the usb devices plugged in even though all the fans work and lights are on. I managed to get it working once after messing around with the usb cables and everything was fine until eventually the same happened and ever since it still posts without display and usb power. Any tips?