Apple MD094LL/A Manuale Utente

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

 2010-09-09

3.  Connect external speakers or 

headphones to audio-out port 

and play a known-good sound 

file. Verify if sound quality is 

acceptable.

Yes

Suspect bad speaker. 

Go to step 4.

No

Audio CODEC or amplifier 

issue suspected. Replace logic 

board and retest.

4.  Inspect LEFT and RIGHT 

speaker cones and speaker 

connection cable for damage. 

Verify if speakers have visible 

damage.

Yes

Replace damaged speaker. 

Retest.

No

Go to step 5.

5.  Install known-good speaker 

into location where distorted 

sound was heard. Verify if 

sound quality improves.

Yes

Replace speaker.

No

Speaker amplifier issue 

suspected. Replace logic 

board.

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

Audio
•  No audio from one or both 

speakers.

•  Audio from speakers distorted

1.  Confirm correct version of Mac OS X is installed. 

See 

kBase #TS1574: Troubleshooting issues 

2.  Go to System Preferences > Sound > Output. 

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.