Vertical/Horizontal Lines

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

Quick Check

Symptoms

Quick Check

 

 

 

Vertical/Horizontal Lines

1.

Boot from install DVD to determine if potential

Vertical lines

 

software issue exists.

Horizontal lines

2.

Verify if issue is visible on an external display.

 

 

 

 

Deep Dive

Check

Result

Action

Code

 

 

 

 

 

1.

Boot from Install DVD and

Yes

Go to Flickering issue, go to

 

 

verify if issue is still visible:

 

Noise / Unstable Flickering.

 

Flickering image

 

 

 

No

Issue likely caused by

 

Horizontal bands of static

 

 

software or driver issue.

 

 

intermittently appear

 

 

 

 

Troubleshoot for software

 

Dock and / or menu bar shift

 

issues. Make sure all firmware

 

 

positions

 

and software updates have

 

Display intermittently flashes

 

been installed.

 

 

 

 

 

on / off

 

 

 

 

 

 

 

 

2.

Verify if issue is visible on an

Yes

Issue NOT caused by internal

 

 

external display attached to

 

LCD. Go to step 3.

 

 

mini DisplayPort.

 

 

 

 

No

Go to step 4.

 

 

 

 

 

 

 

 

 

3.

Remove video card and inspect

Yes

Replace video card.

M24

 

connector for damage or

 

Go to step 5.

 

 

corrosion then reinstall. Verify if

 

 

 

 

No

Issue likely caused by poor

 

 

issue still occurs.

 

 

 

video card connection.

 

 

 

 

 

 

 

 

 

 

4.

Disconnect DisplayPort cable

Yes

Replace DisplayPort cable

X04

 

between LCD display and logic

 

and vertical sync cable or any

 

 

board, and verify if there is

 

other damaged part/module.

 

 

damage to cable or connectors.

 

Go to step 5.

 

 

 

 

 

 

 

Repeat with vertical sync cable

No

Reinstall DisplayPort cable

 

 

 

and vertical sync cable.

 

 

connected between LCD panel

 

 

 

 

Go to step 9.

 

 

and LED backlight board.

 

 

 

 

 

 

 

 

 

 

 

5.

Verify if issue is still present.

Yes

Replace logic board. If video

M04

 

 

 

card was present, reinstall

 

 

 

 

original video card.

 

 

 

 

Go to step 6.

 

 

 

 

 

 

 

 

No

Issue resolved.

 

 

 

 

 

 

2010-09-09

iMac (27-inch, Mid 2010) Symptom Charts — Display  66

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Image 66
Apple MD094LL/A manual Symptoms Quick Check Vertical/Horizontal Lines, Noise / Unstable Flickering, M24