Led Cinema Display brightness control not working after upgraded to macOS Monterey

My setup is a Mac mini M1 connected to a 27" Led Cinema Display via USB-C adapter for mini displayport. Working perfectly with MacOs Big Sur since always. But when I upgrade to Monterey, the monitor's brightness come locked at 50%, and brightness commands disappeared in System Preferences. Brightness keys on Apple Keyboard don't work either (f1, f2, f14, f15) I've tried apps like MonitorControl, but they only serve to decrease brightness ... the maximum brightness in these applications starts from 50% that the monitor is stuck. Anyone else having this problem? What can I do?

Mac mini, macOS 12.0

Posted on Oct 29, 2021 11:15 AM

Top-ranking reply

SmooZ

Level 1

4 points

Posted on Jul 14, 2022 3:48 PM

After installing MonitorControl, first thing I did was using the keyboard to adjust the brightness... the display immediately turned to 50% (oh no!!). Then I filled "DDC max" to 255, nothing happened. But after toggeling "Use hardware DDC control" the display turned to about 80% of brightness. Not good for me because I'm a photographer, highly reliant on the right brightness of the display. But after closing/reopening MonitorControl... whoosh! Brightness was on my side 100% ;) Also after restart and sleep.

After opening the app's preferences the brightness was back to 80% and the "DCC max" field was empty again, so I filled in 255 again and everything is fine now.

So MonitorControl seems a little buggy but I'm very thankful to the guys/girls who did it ..!!!

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56 replies

TLACIVIT

Level 1

23 points

Feb 15, 2022 9:47 AM in response to Mac_Bear_007

Thanks good suggestion. I too think we should ask Apple for the inclusion of the control as well in macOS Monterey for security purposes.

Mar 23, 2022 7:44 PM in response to blaisemarie

https://www.amazon.com/dp/B0836HGBD7

Apr 19, 2022 8:45 PM in response to verdi1987

Hello, I want to thank you for recommending the adapter from Amazon for the LED Cinema Display to the MacStudio. It works great!

Thank you.!

Apr 19, 2022 8:48 PM in response to blaisemarie

Glad it worked out!

Jun 2, 2022 2:11 PM in response to leoluzacmp

I don't know what system you are using but this app doesn't work on Big Sur

Jun 2, 2022 2:12 PM in response to Mac_Bear_007

MonitorControl does not work in Big Sur

gspeasl

Level 1

12 points

Jun 14, 2022 7:27 AM in response to Mac_Bear_007

Thank you! This worked beautifully on my 27" Cinema Display.

Jun 15, 2022 11:49 AM in response to gspeasl

The app "Lunar" actually works if you are using Big Sur. MonitorControl does not work in BigSur.

ScanHEAD

Level 1

10 points

Jun 22, 2022 6:51 AM in response to maoliver92

Thanks again but the same is having no effect at all here.

Jul 19, 2022 9:46 AM in response to maoliver92

It works, thank you!!

Nov 6, 2022 5:15 PM in response to Mac_Bear_007

THANK-YOU!!!! I just spent hours and hours and a call to apple to try to fix this. YOU SAVED ME! Thank you! Worked like a charm!

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Led Cinema Display brightness control not working after upgraded to macOS Monterey