I'm buying a used PowerBook G4 titanium 800mhz 512 from a friend, they tell me that the screen on the powerbook doesn't work right... guess the computer works just fine, but the screen has a "scrambled" signal... still have yet to see it for myself... they replaced the screen with a new one, and still no fix... the catch is that the computer will still run an external screen with no problems...
Could anyone tell me what might the possible problem? and also I currently own a PB G4 400 mhz 256. This machine functions properly and I would be willing to switch out the parts from my old machine into the new one if anyone could give me hints as to what might work and do the job..
Thanks so much.

Doge connection to the powerbooks screen?

Or most probaby the video card.