iMac 5K, 27-inch 2020 screen issue when waking from sleep

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Level 1

7 points

iMac 5K, 27-inch 2020 screen issue when waking from sleep

Intermittently when my iMac 27" 5K 2020 wakes from sleep, the right half of the screen has a very slightly different contrast than the left half of the screen. This is noticeable if a window with a dark background straddles the centre point of the screen.

To restore the screen to where both halves have the same contrast, I need to turn on True Tone in Settings/Display, and then turn it off (I keep True Tone off by default).

Has anyone else noticed something similar?

Posted on Nov 14, 2020 4:08 PM

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Answer 1

rkaufmann87

Level 10

148,606 points

Nov 22, 2020 6:11 PM in response to scottandlee

See what happens when you disconnect all of your external peripherals including the Drop. Physically disconnect them and then re-test, if the problem goes away then you know it is one the peripherals. Then it is simple matter of elimination.

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Answer 2

Jan 27, 2021 8:58 AM in response to Hawaiianteg

I had the same issue and was worried it was a hardware problem with my display, but when I tried @scottandlee's trick of turning truetone on and then off again, the problem was gone.

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Answer 3

Jan 10, 2021 11:18 PM in response to scottandlee

Same happens on my 2020 iMac as well. Usually happens after sleeping and rebooting usually fixes it. Prob something to do with the timing controller. I hope they release a software update that resolves it.

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Answer 4

scottandlee Author

Level 1

7 points

Nov 22, 2020 12:30 PM in response to rkaufmann87

I believe the computer sleeps when the display is off. Under "Energy Saver" the "Prevent computer from sleeping automatically when the display is off" is unchecked.

BTW, the fact that you have NEVER had an issue does not in any way invalidate that I do have an issue. I've also had Mac, since System 7 and NEVER had an issue either. But again, I have the issue now.

Thanks for your "help"

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Answer 5

jeremy_v

Community Specialist

Nov 22, 2020 11:51 AM in response to scottandlee

Hi scottandlee,

Thanks for using Apple Support Communities. We understand you're running into an issue with your Mac display. We're happy to provide some information to help.

It sounds like you've found a work around that works temporarily. We'd also like to share the resource below with you and have you check out what to do to resolve display issues.

If your Mac display doesn't look right

Cheers!

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Answer 6

rkaufmann87

Level 10

148,606 points

Nov 22, 2020 12:00 PM in response to scottandlee

Most experienced users do not use sleep. I also have a 2020 27" and since 2007 and about 12 different versions of Mac OS (beginning with 10.4.x to 11.x, I have been using the Turn Display Off feature and have NEVER had issues.

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Answer 7

rkaufmann87

Level 10

148,606 points

Nov 22, 2020 12:43 PM in response to scottandlee

Okay then please do the following and no need to be critical to someone attempting to help you. If you don't want assistance then well I won't.

You can save you and us a lot of time and effort if you do the following:

Please navigate to the Mac App Store or navigate to www.Etrecheck.com and download the free version of EtreCheck. Once you have you downloaded the app and installed it, please run the report and save it. This report will help us get a good idea what has been installed on your system and help us be able to diagnose what may be wrong.

When you have your report, you can attach it when you reply to this message and we can then review it and help you determine what is needed to get your system running well again.

For instructions on how to download your EtreCheck report and attach it to your reply to this message please click https://discussions.apple.com/docs/DOC-250000211

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Answer 8

scottandlee Author

Level 1

7 points

Nov 22, 2020 5:48 PM in response to rkaufmann87

etrecheck report

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iMac 5K, 27-inch 2020 screen issue when waking from sleep

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