Troubleshooting Symptom/Cure Tables: System Problems After Startup - 44
Sound Out Problems
Sound out problems refer to a lack of sound coming from the internal speakers (located
on the front of the unit directly below the display), external speakers (connected via
the I/O panel to the speaker connector on the logic board), or both.
Possible Cause Possible Fix
Control Panel setting is
incorrect.
First, disconnect any external microphones, speakers or
headphones. Next, verify that volume setting in Control
Panel is adequate and that mute is not checked. Test the
for sound coming from the internal speakers. Do you
have sound now?
Yes: If the initial sound out problem was with the
internal speakers, the problem is solved. If you
reconnect the external sound out device and it is not
working, the problem may be with the external device
itself or its cable. Replace the external microphone,
speaker, or headphone in question with a known-good
device. If the problem persists, replace the logic
board.
No: Go to next step.
Corrupted PRAM. Reset parameter RAM. Hold down <Command> <Option>
<P> <R> during startup but before “Welcome to Macin-
tosh” appears.
Loose speaker connection. Verify that both ends of the internal speaker cables are
attached securely.
Loose audio cable. - Reseat the audio cable (922-4039) located on the
divider panel, under the CRT.
Bad audio cable. - Replace the audio cable (922-4039).
Bad speakers. - Replace the speakers.
Bad logic board. Plug known-good headphones or external speakers into
the external jack. Do you get sound?
Yes: Go to next step.
No: Replace the logic board.
Bad headphone board. - Replace the headphone board.