I recently was able to purchase a 15" 700 Mhz iMac G4 with a broken HDD for $20. After replacing the drive and seemingly getting everything in working order, a new problem with the video on the built in display scrambling or not even starting up arose. The problem either manifests in the form of a black screen with whitish blotches moving across it at startup, or a frozen image with colored vertical lines and scrambling while running a program. The former happens when I move the computer, and can sometimes be remedied by shutting it down and then giving it a good whack/jostle before starting it up again, other times I have to open it up again and move the wires around a bit and re-insert the video cable, and the latter happens when I'm doing something that puts a heavy load on the CD drive (it's happened twice while attempting to play Diablo during a load screen). I'm pretty sure that it's either due to the monitor cable inside coming loose/moving and/or some type of signal interference from another part of the machine. How can I go about keeping this from happening? It's frustrating have the video crap out at random, or even not work at all. There must be some way of positioning/securing/shielding that video cable that will fix this issue.