I was given a powerbook g4 400mhz titanium that doesn't work, I'm retired and love working on electronics, monitors, power supplies, etc.. I don't know what os it has. The power supply works but nothing else. I can't find schematics for it anywhere, though I've found all kinds of take apart manuals. It hasn't got an airport card and the battery is dead. I think. Can anyone help me with a manual that has schematics? I have also checked two of the fuses on the logic board and they are good. thanks,fo fo too