Hi guys. My wife has a three-year old iBook G4 and yesterday while she was doing some work, the screen just went black. By the time she brought it to me the machine was shut down. I hit the power button and it started to boot up, but about five seconds later it shut itself down again. I kept playing with it and I was able to get back in to OS X and I played with it for a few minutes and all seemed fine. I then shut the screen and put it to sleep, then when I tried to wake it back up it shut itself down once again. After a few more tries of getting it back in to the OS I was able to get all her files off the hard drive, but the problem is still there. Has anyone heard about this before, or have any ideas? My guess is that it's the logic board, but that's just a guess. Any help would be appreciated. Thanks!