iMac Manual

iMac (27-inch, Mid 2010) Symptom Charts — Startup and Power 48
2010-09-09
Corrupted Video
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
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 rmware 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 le
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.