Recently, I decided to get my 12" PB G4 (1.33ghz) off the shelf and fire it up. Basically, it is working fine except for a completely black LCD. The backlight seems to work fine. Video is displayed correctly on an external monitor (so I don't think it's a GPU issue). Just nothing on the screen. No obvious damage. No drops or falls since the last time it was working. I'm at a loss. Thoughts?