Apple MD094LL/A manual Audio No Audio from Built-in Speakers, Symptoms Quick Check

3. Connect external speakers or	Yes	Suspect bad speaker.
headphones to audio-out port		Go to step 4.
and play a known-good sound
	No	Audio CODEC or amplifier	M09
file. Verify if sound quality is
		issue suspected. Replace logic
acceptable.
		board and retest.
4. Inspect LEFT and RIGHT	Yes	Replace damaged speaker.	L11
speaker cones and speaker		Retest.
connection cable for damage.
	No	Go to step 5.
Verify if speakers have visible
damage.
5. Install known-good speaker	Yes	Replace speaker.	L11
into location where distorted
sound was heard. Verify if
	No	Speaker amplifier issue	M09
sound quality improves.
		suspected. Replace logic
		board.

Audio: No Audio from Built-in Speakers

Unlikely cause: LCD display, power supply, hard drive, optical drive, fans

Quick Check

Symptoms	Quick Check
Audio: Built-in Speakers Have No	1.	Confirm correct version of Mac OS X is installed.
Audio		See kBase #TS1574: Troubleshooting issues
• No audio from one or both		with bi audio from built-in speakers on Macs
speakers.	2.	Go to System Preferences > Sound > Output.
• Audio from speakers distorted		Verify that sound output device is set to internal
		speakers.
	3.	Go to System Preferences > Sound > Output.
		Verify that “Output volume” setting is set above
		the minimum level and that “Mute” checkbox is
		not selected.
	4.	Go to System Preferences > Sound > Output.
		Verify that “Balance” slider is set to middle
		position so left and right speakers are both used.

2010-09-09 iMac (27-inch, Mid 2010) Symptom Charts — Input/Output Devices  98