Mechanical

Noise/Hum/Vibration

Unlikely cause: LCD panel, glass panel, enclosure, cables

Quick Check

Symptoms

Quick Check

 

 

 

Noise/Hum/Vibration

1.

Verify that the vents on the bottom and

Buzzing noise

 

back of the system are free of dust and other

Rattling noise

 

obstructions that might inhibit proper airflow

 

through the system.

Ticking noise

 

2.

Launch Applications/Utilities/Activity Monitor.

Squeaking noise

 

 

 

Determine whether an application or process is

 

 

 

consuming a high percentage of CPU bandwidth.

 

 

 

CPU-intensive applications can cause the fans

 

 

 

to run fast in order to maintain the proper

 

 

 

internal system temperatures. If needed, quit the

 

 

 

application or restart the system to resolve the

 

 

 

issue.

 

 

3.

Eject optical media from optical drive. Out-of-

 

 

 

balance optical media can generate audible

 

 

 

noise. To resolve try a different brand of media.

 

 

 

For additional information, go to Optical Drive

 

 

 

Noisy symptom flow.

 

 

4.

Tilt display to hinge limits to determine if

 

 

 

mechanical noise is generated by the hinge

 

 

 

mechanism. For additional information, go to

 

 

 

Stand/Hinge Issues symptom flow.

 

 

5.

Play sound sample at loud and soft volume

 

 

 

levels to determine if the noise is caused by the

 

 

 

left/right speakers or the amplifier circuit. Plug

 

 

 

external headphones to identify whether the

 

 

 

noise comes from audio out or from other source.

 

 

 

For additional information, go to Audio: Built-in

 

 

 

Speakers Have Distorted Sound symptom flow.

 

 

6.

Adjust the display brightness to determine

 

 

 

whether the noise is related to the brightness

 

 

 

level. For additional information, go to Noise/

 

 

 

Unstable Flickering symptom flow.

 

 

7.

Run latest available Apple service utilities.

 

 

 

 

2010-09-09

iMac (27-inch, Mid 2010) Symptom Charts — Mechanical  118

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Apple MD094LL/A manual Symptoms Quick Check Noise/Hum/Vibration, Stand/Hinge Issues symptom flow