I have a desktop computer that won't start at all, I had it for years, and now suddenly when I press the power button I get no beeps, no fans spinning, no hard disk spinning. And the amazing thing that it sometimes works when I press the power button and every thing works normally. Sometimes it works after an hour, 10 hours or 10 minutes after I press the power button and this problem happens when electricity goes out and comes back. If I managed to turn the computer and no power outage happened. I am able to keep turning it on. But when the electricity goes off and on. And I press the power button it may turn on after an hour, two, 10 or not at all.