Is this likely a hardware problem with the screen or a system software problem?
MacBook Pro, Mac OS X (10.6.8)
Posted on Mar 18, 2012 5:22 PM
Q: My Powerbook G4 powers on but the screen remains black.
Hi John ...
Try resetting the Resetting PowerBook and iBook Power Management Unit (PMU)
If that doesn't help, run the The Apple Hardware Test
Follow the instructions for PowerPC.