The black screen issue seems pretty prevalent on these G4 ibooks. I have two old G3s and they still work great. Here's my problem on the G4: Black screen, no trace or flicker of anything. Have reset both PRAM and PMU. Still black. I removed extra RAM and the Airport Extreme card. No change. Computer works in target mode. I can read and write to the drive from another computer via Firewire. No image on an external monitor so it doesn't appear to be an inverter or backlight problem. I suspect the video subsystem on the motherboard but I hope that's not it and I don't know the wiring for these, so I can't judge. Squeezing the area left of the keypad where some are known to have a badly seated chip made no difference, even when I put varying amounts of pressure on it. Any ideas? It's such a great little machine. I wish it had the same reliability and longevity as my G3s. I'd like to get it working.