My computer was asleep 12 hours and I opened it up, it made the usual startup sounds but the screen was completely black. This has happened before but I just needed to jiggle the mouse pad or shut it/reopen it and the screen would appear. This time that did not happen, it's been about an hour and the screen is still completely black. I restarted it by holding the power button and I can hear the motor stop but when I turn it on the white LED light is on but I do not hear the startup chime, I just hear the motor start then the humming of the steady motor but the screen stays black. I also have turned it off and removed the power cord as well as the battery but the same scenario happens after I put the battery back in and start it up. I have an appointment with the Genius Bar tomorrow but really don't know anything about computers or the hard drive. I would really appreciate hearing any possible causes before my appt. I've read some things about The NVIDIA GeForce 8600M GT graphics processor repair extension program but don't really understand it. Besides the Genius Bar is there anywhere else I should have it looked at? My AppleCare warranty is expired.