Chosen Solution
Three days ago grey horizontal lines appeared on my Thunderbolt display. After a few minutes they disappeared only to appear again after a while. It happened three or four times and now they stay on permanently. I connected the display to two different laptops and the lines were visible in both cases. I have also tried a new thunderbolt cable but it didn’t help. Any help with pinpointing the issue would be appreciated.
Sadly lines are a symptom of a TAB error. This is were the glass LCD panel electrical pathways is converted to a flex ribbon cable. The LCD has metal oxide deposited as electrical pathways within the panel the alignment or the joint of the interface has failed. Sometimes a bit of pressure in the area can re-establish the connection otherwise you’ll need a new LCD panel.
