So I have a desktop that I've been using for about 3 years now. I've changed the motherboard once about half a year ago, and bought another terabyte of hard drive to use. Everything seemed to work fine until today. When I clicked the power button, the fans ran for about half a second, and then it made a single short beep (more like boop) sound and shut down. Everytime I've clicked the power button for the last 12 hours the computer just made that sound and shut down. Is it time to change the psu, or change the motherboard again?