iBook G4/1.33 GHz, System Profiler says batter is "Good" and "Charging", but battery won't charge (though percent charged on the status bar does change!) - took it to the Apple store and they tried different batteries and AC adapters to no avail. The tech quietly mentioned ifixit.com, and an inexpensive part I could attempt to replace. Would that be the DC-In? Suggestions or warnings appreciated.