Apple Powerbank G4 manual Half keyboard is illuminated, Microphone is not working

2.Check the keyboard backlight cable connection to the top case flex cable and the top case flex cable connection to the logic board. If the connections look good, change the top case.

3.Replace logic board.

Half keyboard is illuminated.

1.Check the keyboard backlight cable connection to the top case flex cable and the top case flex cable connection to the logic board. If the connections look good, change the top case.

Microphone

The microphone is not working

1.Check the Sound system preference pane and verify the selection under the Input tab is for the built-in microphone.

2.Check the signal level and level meter and adjust the gain.

3.Reset PRAM (Press the power button, then hold down the Option-Command-P-R keys until you hear the startup chime at least one additional time after the initial startup chime).

Warning: Resetting the PRAM will permanently remove a RAM disk, if present and all of its contents. You will also need to reset the date and time (using the Date & Time system preference pane).

4.If there is no sound output from the internal speaker as well as the microphone not working, verify cable connections.

5.Replace sound board flex cable.

6.Replace the sound board.

7.Replace the speaker assembly.

8.Replace the logic board.

28 - PowerBook G4 (17-inch) Troubleshooting Hardware Symptom Charts