Hey all, I have an ibook G4 800mhz that is having trouble waking from sleep. When I open it, the sleep light will go off but nothing will come up on the screen. So I hold the power button for 10 seconds and let it power up and on the power up it will make a higher tone that lasts about 3-4 seconds and the sleep light blinks in quick succession for about 3-4 seconds. Then all is good as it normally powers up. Any ideas on what is causing this and how I can fix it? Thanks.