Chosen Solution
Hello fellow iFixers, My iMac has this vertical area of slightly darker pixels, please see attached image. I’ve found a bunch of similar questions both here and on Google, but they all seem to be more severe cases than mine. It’s really barely noticeable, mostly on dark/contrast backgrounds, especially if I make the display very bright. It doesn’t seem to affect the image quality, it just… bothers me. I was planning to upgrade the RAM in this machine, and if there is a simple fix for this, I may as well go ahead with it. I know it’s a rather involved process, but since I was going to open it anyway… any suggestions greatly appreciated!
Update (08/11/2019) Update: not sure if it’s of any significance, but it doesn’t show when I shared the screen on someone else’s macbook. In addition, however crazy that may sound, it doesn’t seem to affect any other desktop backgrounds (even dark ones), other than the two Mojave images (and their lock screens).
Update (08/12/2019) I found an adapter and connected an external monitor. It shows no issue even with the same Mojave background, but the stripe is present on the built-in display.
“If it ain’t broke, don’t fix it” is the best advise I can give on this one.
If this really bothers you, you’ll need to replace the display assembly. Sadly, there is no magic here. The TCON board within the display assembly has a scanning issue. While not overly hard it is expensive! I personally would live with it. iMac Intel 21.5" EMC 2544 Display Replacement iMac 21.5" LCD Panel & Front Glass Assembly - NewiMac 21.5" LCD Panel & Front Glass Assembly - Grade-A
