My Powerbook G4 started giving me trouble about a year ago... tried everything including a new apple battery.. It would go to sleep and not wake up. Had to remove battery to shut it down. Then it got harder to get to go again. Had to remove battery and play with it for a half hour or longer. It would start, then stop, I would start it again and then it would quit again. It acts like it needs to be warm to run. The more time I start it the "warmer" it gets and then finally it will stay on all day. I can shut if off and turn it back on and no problem. I can come back hours later and it will start and run fine. If I leave it off for a couple of days... the same problem starts all over again. I have shut off the sleep modes, reset everything etc. but does not fix the problem. I finally bought a new MacBook Pro but was wondering if anyone knows what happened?