I have a powerbook g4 1.67ghz 17". It has developed a few problems: 1. The battery will not charge at all and when the power cable is removed it shuts down imediately. 2.The only way to restart the powerbook is to do a reset of the pmu where you disconnect power and battery and hold down on switch for 5-10secs. 3.The USB ports have stopped working. Otherwise it runs as normal. Could this be the logic board battery needs replacing or is there another fault! Any help appreciated.