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Original post by: Robert G ,


Image glitching randomly after boot


Hi, i hope anyone have solved this issue or determine the cause of it.

My iMac display suddenly started glitching. (No water damage or physical damage)

As i turn on the iMac on boot screen the apple logo can be seen perfectly but as soon as it boots to OS the image goes beserk.




As i move the mouse around the image distorts randomly. Its impossible to work.

What have i done so far;

# PRAM/SMC Reset
# Tested an external monitor (same issue also persists)
# Upgrade OS
# Flash EFI Upgrade
# Swap RAM cards
# Tested new RAM cards
# Tested single slot RAM one-by-one since there are 2 slots
# Checked LCD connectors
# Cleaned fans
# Remove and reapply new thermal paste (Processor and GPU)

So far no luck,

Hope anyone can help, Thanks in advanced!


iMac Intel 21.5" EMC 2544