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

First off, thanks to everyone on the board.

My setup - Mac Mini M1, Thunderbolt Display off USB-C, LED Cinema Display off HDMI

Installed Monitor Control on Mac Mini M1 running Monterey and adjusted the DDC Max to 255. Brightness level still stuck at 50%.

Installed Monitor Control on a MacBook Pro running Catalina, connected Cinema Display, and adjusted the DDC Max to 255.

And voila, was able to get brightness to 100% in this environment (Macbook Pro / Catalina / DDC Max 255)

Afterwards, I disconnected the Cinema Display and connected it back into the Mac Mini M1 setup. Bam 100% brightness. The brightness level was maintained from where I had it prior to unplugging from Macbook Pro.

Hope this helps someone.

I have the same monitor

Managed to fix it using Monitor Control

Using Monitor Control with the config below. After adding this config, the brightness was full in the app, so I just moved it back and forth and it was solved.

Before adding 255 to DCC max in brightness roll, the brightness slider didn't work to get the monitor brighter, just darker

By the way I'm using monterrey 12.3.1

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!

Obsolete. ? These display still work very well.

Anyway let's scrap good products to make even more money. And continue to ruin the planet.

(and also not pay income back to the nation they grew in and from btw)

Luckily there still good will people. Thanks for MonitorControl.app

see leoluzacmp's post.

Obsolete products are not tested with current OS and resolution is not guaranteed.

Check out HT201624 - Obtaining service for your Apple product after an expired warranty

https://support.apple.com/en-us/HT201624

Same problem this was a bug / omission in the build of macOS Monterey. Apple please restore this service. I have a brand new Mac-mini and I would like to use my Apple LED Cinema Display 27 in. properly see image below.

Hitting my head on the desk with this issue as well. Can you “downgrade” the OS to Big Sur if it came pre-loaded with Monterey? Got our fam a brand new Mac mini for Christmas, as I had an extra 27” Cinema Display from my studio. Made sense to me, right? This display is gorgeous.

After finding out the hard way that thunderbolt 2 to thunderbolt 4 adapters don’t work… finally got the MDP - TBolt4 in the mail today. Display and audio now work, but the brightness is definitely an issue. Photo/Video editing and working/editing in any DAW is going to suck at 50% brightness.

Maybe I’ll try the third-party app? Any info as this progresses will be great though. Thanks for posting!

Hi, I have the exact same setup and while the MonitorControl app allowed me to control my brightness again, the maximum brightness was at most around 50% of what the LED Cinema Display is capable of. I solved this by connecting the monitor to my old 2013 MBA and manually set the brightness to maximum by holding down ctrl and the adjusting the brightness with the F1/F2 keys. It seems that the Cinema Display "remembers" its brightness settings, when I reconnected it to the M1 Mac mini I was back to full brightness. This still doesn't ultimately solve the brightness control issue, but at least I can see what I'm working on now. Hope this helps, cheers.

I just got a Mac Studio and connected my trusty LED Cinema Display. I guess I didn't notice the lack of brightness controls in Monterey until now. It's unacceptable Apple would drop something as simple as a brightness control. The Cinema Display is my secondary monitor, and I can accept the current brightness. If I need to change it I'll try the third-party utilities.

What sort of an adapter did you use to connect your LED Cinema Display to your Mac Studio? My Mac Studio is a few weeks away from delivery, and I'd like to be able to use my LED Cinema Display/24" with it.

I have a 30" Cinema Display, connected to a new Mac Studio running Monterey 12.4 via a DVI - USB C adaptor.

Displays control panel took a moment to adapt to the addition of a new external monitor but the brightness was good (and had been good when previously connected to a 2014 iMac). Following a restart however, the brightness has stuck at around 50%. Displays control panel offers no Brightness control. I have installed Lunar, Monitor Control and Brightness Slider, with no luck whatsoever.

Each of those additional controls (recommended here and on MacRumors by users experiencing similar problems) shows Cinema Display Brightness at 100%. Monitor Control and Brightness Slider do enable further dimming (to -50%) but Lunar has no effect whatsoever. Changing brightness via the F1 and F2 keys works as normal on the new Studio Display but shows a lock under the Cinema Display on-screen brightness display.

Is there any way of unlocking the Cinema Display fixed at 50%?

Thanks for the suggestion but no joy, I'm afraid.

Do I need to restart or change any other setting?

I'm also wondering if I should uninstall the other two controls recently added: Lunar and Brightness Slider, as they also have no effect?

I'm using monterey 12.4 and a cinema display 27'' 2010.

The only way I managed to fix was doing what I send here.

After I changed the brightness ddc max to 255, moved the brightness down and up the monitor reached its maximum brightness.