Hi all, i have a 17" IMac G5, i switch it on and it starts booting etc, but the screen has a checkerboard effect all over it. When it gets the desktop, all it displays is the mouse with a checkerboard over it as well, now you can move the mouse but nothing else i.e. no icons etc. When i try and boot from the O/S disc, all i get are the fans running at full speed and again a checkerboard screen. I understand that the Capacitors go on these IMacs, so i recapped the entire board but this didn't help at all, just the same problem I know its not the screen itself, so the only thing left is the GPU. I know these can have problems as well. Should i try and reflow the GPU with a Heat Gun?? Does this help at all?? Any advice would be great Thanks.