(my computer is a 12" G3 ibook 600mhz, late 2001 model, with dual usb.)

So, last week I turned on my ibook, and after five min, it froze, and I couldn't do anything. I've had this computer for three years, and nothing like this has ever happened. so after try all keyboard commands I could think of, I restarted it, as this will usually fix problems. but when It came back, it started up frozen. so Then I started up again, and this time it seemed to start up, but the screen didn't turn on, the computer was running, but the screen was off. and at this point I couldn't turn it off or restart, so I had to take the battery out to turn it off. I then let it sit overnight. the next day I camp back ,and it turned on, but then after a minute, it froze again. then did the same thing it had done the day before. I powered it off again, as I had to go and didn't have time for it. the following day, I started it up from the diagnostic disk, and it worked a little better. I was able to move the mouse, but it was very jumpy, and parts of the screen had artifacts. but I was able to start the system test. but after about five minutes of the test, the computer froze again. and that's where I'm at. My thought is that my logic board is toast, but if anyone has a better idea, please let me know. All thought appreciated, thanks