iMac (27-inch, Mid 2010) Symptom Charts — Display 66
2010-09-09
Vertical/Horizontal Lines
Unlikely cause: power supply, hard drive, optical drive, fans, speakers, camera, microphone
Quick Check
Symptoms Quick Check
Vertical/Horizontal Lines
• Vertical lines
• Horizontal lines
1. Boot from install DVD to determine if potential
software issue exists.
2. Verify if issue is visible on an external display.
Deep Dive
Check Result Action Code
1. Boot from Install DVD and
verify if issue is still visible:
• Flickering image
• Horizontal bands of static
intermittently appear
• Dock and / or menu bar shift
positions
• Display intermittently ashes
on / o
Yes Go to Flickering issue, go to
Noise / Unstable Flickering.
No Issue likely caused by
software or driver issue.
Troubleshoot for software
issues. Make sure all rmware
and software updates have
been installed.
2. Verify if issue is visible on an
external display attached to
mini DisplayPort.
Yes Issue NOT caused by internal
LCD. Go to step 3.
No Go to step 4.
3. Remove video card and inspect
connector for damage or
corrosion then reinstall. Verify if
issue still occurs.
Yes Replace video card.
Go to step 5.
M24
No Issue likely caused by poor
video card connection.
4. Disconnect DisplayPort cable
between LCD display and logic
board, and verify if there is
damage to cable or connectors.
Repeat with vertical sync cable
connected between LCD panel
and LED backlight board.
Yes Replace DisplayPort cable
and vertical sync cable or any
other damaged part/module.
Go to step 5.
X04
No Reinstall DisplayPort cable
and vertical sync cable.
Go to step 9.
5. Verify if issue is still present. Yes Replace logic board. If video
card was present, reinstall
original video card.
Go to step 6.
M04
No Issue resolved.