My son's MacBook won't start up. He pushes the power button. The chime rings and then the white screen w/ the gray apple and the gray spinning wheel stays on... nothing else happens. We've tried all of hte following with no result. Start from the system CD. Push power button and hold 'C'. The CD spins for a while and then it's kicked out. Push power button and hold 'Shift'. Push power and hold 'X'. Press the control key, the command key, and the power button simultaneously and hold for three seconds to try to restart the computer. After pressing the power button, hold down these keys simultaneously: Command-Option-P-R, until you hear the start up chime at least one additional time after the initial start up chime. Nothing seems to be working. Any other ideas?