Before I went to sleep last night, I put my PC to sleep as I usually do; when I woke up and moved my mouse to wake up the comp, nada. Monitor stayed off, no lights on keyboard. Lights on the case were on, and the fan started up. I checked all connections, tried turning everything off and on, unplugged and replugged everything; same result. Turning on the computer starts the fan and case lights, but no signs of life from keyboard or monitor. HALP
When my computer did that, the hard drive was dead.
Try some of the suggestions in this thread: