Справочник Пользователя для Apple MD094LL/A

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

 2010-09-09

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

Noise/Hum/Vibration
•  Buzzing noise
•  Rattling noise
•  Ticking noise
•  Squeaking noise

1.  Verify that the vents on the bottom and 

back of the system are free of dust and other 

obstructions that might inhibit proper airflow 

through the system. 

2.  Launch Applications/Utilities/Activity Monitor. 

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 

 symptom flow.

4.  Tilt display to hinge limits to determine if 

mechanical noise is generated by the hinge 

mechanism. For additional information, go to 

 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 

 symptom flow.

6.  Adjust the display brightness to determine 

whether the noise is related to the brightness 

level. For additional information, go to 

 symptom flow.

7.  Run latest available Apple service utilities.