This iBook boots to a gray screen. No blinking, no shades or colors changing or other graphic anomalies, just gray. I know it's booting because I can connect and use it via Screen Sharing. Using its keyboard, trackpad, ports, optical drive and speakers, it shows that everything is working properly but the display is simply gray. I tested it with several internal displays and several internal display cables, no luck. Ideas? It's an A1055 14", 1.33ghz.