Solved Laptop Screen Very Dim Powerbook G4 Aluminum 12 1 1 5 Ghz

Chosen Solution

Can barely make out images on laptop screen. Screen displays fine on external monitor. Thought it was the inverter board, so replaced, but same problem. Replaced logic board, still same problem. Any ideas? Brightness is whole way up.

If I read you correctly you have replaced the inverter board and the logic board. The unit functions well with an external monitor. It would seem that leaves only the cable from the logic board to the inverter board or the LCD itself. I would try the cable as the lower cost part first. I am including the link for replacing the LCD but hope you won’t need it. Good luck Ralph PowerBook G4 Aluminum 12" 1-1.5 GHz Display Replacement

There’s only the LCD & the Display Data Cable (LVDS) left and it doesn’t sound like the cable.