2020 27" iMac display gets half opaque when shutting down computer as seen below. I already went through disk utility to see if there were any issues, as well as erasing the drive and re-installing MacOS (Big Sur) and restoring from a Time Machine Backup.
Boot into Safe Mode by booting with the Shift key held down and check there to see if the problem persists. Reboot normally and test again.
NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following;
• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files
I just turned off True Tone to test if that was the case (and if so, discuss with Apple Support) and the issue still happened, so in my situation at least it’s not due to having True Tone off. Perhaps you may want to give it a try.
I updated to 11.2.1 and am still having the issues. Before the update, I had tried different channels and I received a call from Apple on the matter - the person was not an engineer - but based upon what I had shared, including the picture and the description, he felt confident this is a software issue and that it doesn’t affect performance, but I told him that I didn’t pay +$2,000 for an iMac to have this issue and that I didn’t know if it would lead to future problems. He told me he will share the list with the engineers so they can figure it out and asked me as well to provide this type feedback through https://www.apple.com/feedback/ as the forums might/might not be seen. I’m glad he called and listened, hopefully it will be addressed in a future software update.
The exact same thing (display half opaque when shutting down) happens to me all the time, and yesterday the screen suddenly split in two like shown in the photo, while using the Safari browser. It happened twice, and I had to restart the iMac every time it happened to get it back to normal.
Hi. About two months ago I've contacted Apple Support, and after a lot o report generations, upscaling in support to higher levels, the answer that I've received is that this problem should be fixed in the next Mac OS version, i.e., Mac OS 11.3.
I've installed Mac OS 11.3 and the problem continues... If you let the iMac turned on for a day of work, when you shutdown, it shows the screen divided, with one side opaque like this thread tells.
I'll be contacting Apple Support again, but until now, no solution....
Mine too. It doesn't do it if shutting down quickly. Also it stopped after shutting down after safe mode but has reverted to doing it after the next regular boot up.
Does this suggest its a piece of software causing a conflict with the split screen function - which I never use?
Very annoying problem and very little other information out there it seems.
I don’t know if that could be the culprit, though I had read in another forum (outside of apple’s) of a MacBook having issues with the split screen option. This week I will be reaching out to Apple support on the matter and will let you know.
Thanks for the feedback and time spent on the issue. If you do manage to contact them again it would be useful to know whether there is a possibility it's a hardware issue. My iMac is only 2 months old.
Also safe mode turns off most stuff, but to be useful, it needs to be able to identify what the problem software is.
Thanks. At least in my case, the two instances where I have boot in safe mode, I have not seen the issue come up when I shut down, but as soon as I start up normally and it’s been on for over 20-30 minutes, the issue repeats. I already took the iMac to the local Genius Bar and they said they couldn’t replicate the issue and I got my iMac with the drive wiped out and the original macOS (Catalina, as diagnostics didn’t show any issues with hardware/software). They ask me to I wait with Catalina installed and see if the issue would come up (before installing Big Sur again) and it didn’t happen when I shut it down, then I went ahead and reinstalled all my files from back up with Catalina on and turned it off after about an hour and the issue didn’t happen. Then went ahead and upgraded to Big Sur and it happened again. I wiped out the drive again and without installing my files from back up, just upgraded directly to Big Sur as if a new computer and to ensure it had nothing to do with any corrupt files and after leaving it on for over an hour, the issue happened again.
It’s very frustrating I can’t return this computer after having this issue start within a month of having it and with three months and no clarity of what is going on with this issue and paying over $2000 for this iMac to have this happen.
I also contacted them, and got a phone call back a couple of months ago and was told they were adding this issue to the list of issues to fix, but so far nothing has been fixed with the latest update…
I have exactly the same problem but sorry not answer. Did you find an answer anywhere else?
No, I haven’t received any answers yet. With today’s Big Sur update, I will see if it continues and post. If so, I will go through Apple Support.
I just updated to Big Sur 11.1 and when shutting down it did it again, same as the image I shared already.
Its reverted back to the half screen again while shutting down. So not yet resolved.
It happens the same to me
Hi. I have tried yesterday and still not working. Same issue.
2020 27" iMac display gets half opaque when shutting down computer
