My MBP (15" 2.2GHz running 10.4.11) won't wake up from sleep. Even restarting the computer activates the sleep light (non-pulsing) before the display turns on and while it makes a sound like the drive is trying to boot, nothing happens. I have tried booting from the install disk unsuccessfully. While turned on (with the sleep light on) the notebook accepted the install disk and even made sounds like it was reading it but still the screen remains off and the sleep light on. I think I've just about exhausted my ideas. Do you have any ideas?