Hi My PowerBook G4 (1.25gHz 2003-4) has developed a problem all of sudden with the screen. Please see picture. If you're not sure what you are looking at, there are a series of horizontal & vertical lines/patterns in various colours. They are all uniform and not random. The PB starts up OK and you can probably see my desktop image (David Hockney painting) below all the interference. I have since run first aid - done a complete clean install and put a new system on there, but with no luck. I'd like to get it fixed so that my two girls can use it instead of my new MacBook Pro. Any suggestions please? Thank in anticipation of your replies.