Powerbook G4 Screen Distortion...please help me fix

Question

Hey all. This is my first post on this forum, because I haven't owned a Mac since 2009. But I come to this board often to troubleshoot when I am helping my friends/family with their Macs (yeah, i'm the 'computer guy'). Anyway, I now have a Mac that was given to me by a family member that has a very specific problem that I hope someone will be able to help me fix.
It's a 2004 Powerbook G4 (A1046). It turns on, and I hear the chime, but the whole screen is distorted. It's weird because the screen flickers to a normal light blue screen for a second when it changes from the boot screen (with the spinning wheel) to the login screen, but then it remains distorted and I can barely make out anything on the screen. The computer works otherwise.
Here's a link to my Youtube video showing exactly what is happening. http://youtu.be/Ce7bTYFKrdE (around 0:56 is where you can really see the distortion most clearly).
I tried to see if it was a problem with the OS, but since I don't have an OS X install disc, I tried running a live CD of Linux (PowerPC version). I was able to run the live CD, but the distortion remained throughout. I also tried connecting it to my external monitor, but the same distortion appeared across both monitors.
Any possible causes for this you guys can think of, or possible solutions, would be appreciated. Thanks in advance.

Answer 1

Those are rather classic symptoms of video hardware failure. However, quite a few G4 PowerBooks and G5 iMacs whose serials numbers began with W8 experienced actual display screen failures.
Both are bad because so many used parts now offered as repair parts were scavenged from defective computers.
A test to sort whether the video hardware (not worth fixing) or the display unit (maybe worth fixing if you can get parts) is at play, connect an external  monitor. If the video defects reappear on the external monitor, the video hardware is shot and it is time to bid the computer a fond farewell. The video hardware is part of the logic board and replacement boards are scare can can cost as much as a used working Powerbook.
If the problem does not appear on the external, the video hardware is fine but the display unit is bad. You will still be looking for a hard-to-find part. However, one could continue using the computer as a desktop model with the external monitor,
PowerBooks are not easy to service at home. How clever are you with computers and small fiddly bits?