Apple MD094LL/A Manuale Utente

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

 2010-09-09

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

LCD Issues
•  Incorrect/missing colors
•  Distorted/blurred image
•  Pixel anomalies
•  Vertical/horizontal lines
•  Non-uniform brightness
•  Flickering

1.  If display flicker only occurs when the brightness 

level is set below maximum, then jump to topic, 

2.  Run Automatic Software Update to verify that all 

available firmware 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 profile.

6.  Check brightness setting.
7.  Clean glass panel while checking for dust/debris.

1.  Verify if user issue is due to 

flickering, or to an unstable 

video image on the LCD.

Yes

Flickering issue, go to 

Symptom table

No

Go to step 2. 

2.  Verify if issue is incorrect/

missing colors.

Yes

Go to 

No

Go to step 3.

3.  Verify if issue is distorted/

blurred image.

Yes

Go to 

No

Go to step 4.