Try checking the cables that lead to the display, it looks like the display is getting power, but not getting signal. I had this problem with my 17" Studio display. try connecting the iBook to an external display via the mini-vga to VGA adaptor. to verify this. It sounds like that should solve the problem. also, make sure that the display data cable is in the socket all the way, and that there is no damage/frays to it.