Apple MD094LL/A Manuale Utente

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

 2010-09-09

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

Audio: Microphone
•  Microphone not working
•  Microphone audio garbled
•  No sound

1.  Verify that no tape, sticky notes, or other objects 

are blocking microphone located on top of 

computer near camera. Microscopic perforations 

on top of computer must be free of obstructions 

in order for microphone to function.

2.  Go to System Preferences > Sound > Input. 

Verify that sound input device is set to internal 

microphone.

3.  Go to System Preferences > Sound > Input. 

Verify that “Input volume” setting is set above 

minimum level.

4.  Go to System Preferences > Sound > Input. 

Verify that “Input level” indicator moves when 

speaking into microphone.

1.  Verify if boot chime is present 

when system is powered 

ON. Make sure audio output 

preferences are not set to mute.

Yes

Go to step 2.

No

Reset PRAM and retest.

2.  Make sure no cables are 

connected to external sound 

input/output ports. Go to 

System Preferences > Sound > 

Input and verify that “Internal 

microphone” is an available 

option.

Yes

 Go to step 3.

No

Replace audio cable.

3.  Go to System Preferences > 

Sound > Input and verify if 

“Input volume” is set above 

minimum sensitivity.

Yes

Go to step 4.

No

Set “Input volume” slider to 

middle position. Retest.

4.  Go to System Preferences 

> Sound > Input and verify 

if “Input level” indicator 

moves when speaking into 

microphone.

Yes

Microphone and audio input 

functioning. Go to step 6.

No

Suspect bad microphone 

connection. Reseat 

microphone connector on 

logic board. Go to step 5.