Ask Max: G4 Adding Lines To Photos
I have an iMac G4 that started putting lines in my photos in random places in different colors. Is this a video card problem and if so can they be replaced on these older iMacs?
What you describe sounds like it could be a Video RAM issue or an LCD screen defect. When the lines appear on the photos shown on screen those same lines do not print on the image, do they? As long as the lines stay on the screen you can be confident it is a video issue of some sort. The difficult thing with the iMac design is that most do not have ™Video Cards.™ Part of being an All-in-One design is combining the video card and logic board into one unit. It saves on space but it will require replacing the whole logic board, which is costly. It may also be a problem with the cable that runs through the neck of the G4 iMacs, this can wear out and may need to be replaced. The whole neck has to be replaced but that would probably be cheaper than a logic board.
Both repairs should be done through an Apple authorized service center.