iMac Manual

iMac (27-inch, Mid 2010) Symptom Charts — Display 58
2010-09-09
LCD Image Issues
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptom Quick Check
LCD Issues
• Incorrect/missing colors
• Distorted/blurred image
• Pixel anomalies
• Vertical/horizontal lines
• Non-uniform brightness
• Flickering
1. If display icker only occurs when the brightness
level is set below maximum, then jump to topic,
“Display: Backlight Issue / No Backlight.”
2. Run Automatic Software Update to verify that all
available rmware and software updates have
been applied.
3. Verify Mac OS X version installed is the build
version supported on the hardware. Make sure
customer didn’t migrate over old version of Mac
OS X.
4. Allow display to reach normal operating
temperature for about 15 minutes before
evaluating front-of-screen performance.
5. Check display preferences for use of custom
display prole.
6. Check brightness setting.
7. Clean glass panel while checking for dust/debris.
Deep Dive:
Check Result Action Code
1. Verify if user issue is due to
ickering, or to an unstable
video image on the LCD.
Yes Flickering issue, go to Noise
/ Unstable Flickering
Symptom table.
No Go to step 2.
2. Verify if issue is incorrect/
missing colors.
Yes Go to incorrect/missing
colors.
No Go to step 3.
3. Verify if issue is distorted/
blurred image.
Yes Go to distorted/blurred
image.
No Go to step 4.