Chosen Solution
My 12" PowerBook g4 got wet from a leaky roof while the computer was in sleep mode. It will boot and I can log in, however, the display is very, very, very dim. Is there an easy fix that’s not too expensive?
Hook the unit to an external monitor and see if you have normal video. If you do the logic board if probably good but you need to check the cable and connections to the LCD. If those are good you may need a replacement LCD. I am including a link so you can identify your unit and select the needed guides for disassembly and repair. PowerBook