Apple MD094LL/A Manuale Utente

iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power 

 2010-09-09

Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone

Corrupted Video
•  Text and graphics appear fuzzy
•  Image corrupted

1.  Using the KBase article http://support.apple.com/

kb/HT1159 , verify Mac OS X version installed is 

the build number supported on the hardware.  

Make sure customer didn’t migrate over their old 

version of Mac OS.

2.  Set System Preferences > Displays to native 

resolution of LCD. Non-native resolutions are 

unable to produce optimal clarity.

3.  Clean outside surface of glass panel..
4.  Make sure all relevant firmware and software 

updates have been applied. Graphics driver 

updates may be included with software updates.

5.  Boot from install DVD or another known-good 

volume to determine whether a potential 

software/driver issue exists.

6.  When issue occurs, take a screenshot of the 

display (Command-Shift-3). View screenshot file 

on a known-good computer. If image corruption 

can be seen in the screenshot then issue is with 

the video drivers, software, or video/logic board. 

If issue cannot be seen in the screenshot then 

LCD panel and DisplayPort cable should be tested 

further.