When I push the power button to my desktop, and I see the lights on my keyboard light up, it starts up and runs normal while on, but if I shut down, then push the power button to start back up, it won't power on until some time has gone by. It's been doing this for a couple of months. At first it would power back on after 5 minutes. Then it would take 10 or 15 minutes. Now it won't power back on for 1 or 2 hours. Does anyone have any idea what the problem may be?