macOS Catalina brightness control not working

Question

Level 1

9 points

macOS Catalina brightness control not working

I have a 27" late-model 2012 iMac configured for manual brightness adjustment. Starting with the Catalina update the display's brightness goes to the max when logging into the machine and then I have to lower the brightness to the desired level.

I tried letting the system adjust brightness automatically but I do not like how that works.

I prefer a constant brightness but macOS ignores my settings.

I have done a PRAM and SMC reset but that did not help.

Any ideas about what is going on?

Posted on Jan 1, 2020 10:12 PM

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Answer 1

BDAqua

Level 10

245,477 points

Jan 2, 2020 7:46 AM in response to mazapan

To find out if it's system wide or user specific, try this...

Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.

Does it work in the new account?

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Answer 2

mazapan Author

Level 1

9 points

Jan 6, 2020 4:11 PM in response to BDAqua

Unfortunately the problem persisted with the new admin account.

I hope this does not indicate a need for a re-install of the OS.

Thanks for your attention.

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Answer 3

Jeff Donald

Level 7

25,503 points

Jan 6, 2020 4:24 PM in response to mazapan

Not sure this will help, but I had the same issue with my 2017 iMac. It was fixed when I updated to 10.15.2. Are you using the latest version of Catalina?

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