Sound out issues refer to a lack of sound coming from the internal speakers (located on the front of the computer directly below the display), external speakers (connected via the I/O panel on the side of the computer), or both.

This article covers repair procedures for authorized service providers on selected Apple products, but we have published them in the Knowledge Base for the general public for educational purposes. At this time, there are a limited number of repairs that a customer can perform and these are covered under the customer installable parts program http://www.info.apple.com/installparts . If you have not been authorized to perform these procedures, please contact Apple (800-APL-CARE in the USA) or your local authorized service provider to schedule a repair.

DANGER! This procedure exposes you to high voltages that can result in death or serious injury. DO NOT ATTEMPT THIS PROCEDURE IF YOU HAVE NOT BEEN CERTIFIED AS AN APPLE-AUTHORIZED TECHNICIAN.

Products affected

• iMac (Slot Loading)
• iMac (Summer 2000)
• iMac (Early 2001)

Solution

1. Disconnect any external microphones, speakers, or headphones.

2. Verify that the volume setting in the control panel is adequate and that mute is not selected. 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 issue is solved. If you reconnect the external sound out device and it is not working, the issue 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 symptom persists, replace the logic board.
No : Go to next step.

3. Reset parameter RAM. Press Command-Option-P-R during startup but before "Welcome to Macintosh" appears.

4. Verify that both ends of the internal speaker cables are attached securely to the printed circuit board.

5. Remove the installed RAM and turn on the computer. Do you hear a tone indicating no RAM is installed?
Yes : Replace the headphone board.
No : Go on to the next step.

6. Plug known-good headphones or external speakers into the line out jack on the I/O panel. Do you get sound?
Yes : go on to the next step.
No : Replace the logic board.

7. Reseat the audio cable.

8. Replace the audio cable.

9. Replace the speakers.

10. Replace the headphone board.