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

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 ..!!!

To me this looks like a conflict between your apps and the system that doesn't know where to get the display info.

My suggestion would be to uninstall both apps and start all over again. As they don't come with an uninstaller you have to use AppCleaner to also remove all their system files.

Restart and just install MonitorControl as I have seen the best results with this app in my searches.

Note: In the past AppCleaner caused some problems with my F-Secure installation after uninstalling another app.

There's a solution for that here:

https://community.f-secure.com/safe-en/kb/articles/6282-f-secure-product-shows-error-notification-security-cloud-malfunction-on-a-mac-computer

Mac Mini M1, Led Cinema Display, Mini Displayport to USB-C

That doesn't sound far fetched to me. My Led Cinema Display was connected to an old Intel Mac Pro and the brightness was set to 100% as I disconnected it. When I connected the display to the Mac Mini M1 the brightness was still at 100%, but had no slider nor keyboard control.

Only after installing MonitorControl it got stuck at 50% as the max. But as I said after toggeling "Use hardware DDC control" it came back at 100%.

Btw F-Secure is a virus and spyware scanner.

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.

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.

In my case (27" Cinema Display) Lunar is what worked. I did not uninstall Monitor Control until I had verified Lunar was working. I was able to properly color calibrate after Lunar restored brightness controls. It was very straight forward fix in my case. To be clear I tried Monitor Control first with various suggestions and it did not work for me.

I had this problem

In monitor control, try setting brightness DDC max at 255, then adjust the brightness.

Your display settings probably got bungled at some point. Try moving all files in the folder ~/Library/Preferences/ByHost that starts with com.apple.windowserver.displays to a different location for backup and restart your computer. If it doesn't work, try another port on the machine. If it still doesn't work try one of the other suggestions like MonitorControl or Lunar.

Did you try this first? Shouldn't be necessary to use a third party.

Led Cinema Display brightness control not… - Apple Community

Indeed, it did work, in part.

I connected the Cinema HD to my MacBookPro and the brightness was immediately improved, to around 70%-80%. Unfortunately, the connection seemed to affect the trackpad (mouse also) and I could not control the cursor to adjust Display brightness in Preferences.

On reconnecting the Cinema HD to the Mac Studio, the brightness was maintained at the same level, which is a big improvement. MonitorControl, with settings as previously suggested, had no further effect on brightness, however.

On disconnecting the Cinema HD from the MacBook Pro, trackpad (and mouse) functionality returned to normal.

Thank you!! to the developers of MonitorControlLite available from the Apple App Store. Puts an icon in the menu bar that allows slider to control brightness on the Cinema Display.

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

Nope, alas, no change at all.

Having done all that, my Cinema HD is still stuck at 50%.

From reading some of the other posts on this page, it would appear that a) this problem is mostly particular to M1 Macs running the latest OS, and b) some have had some success connecting their Cinema HD to an older Mac running an older OS. It seems that when doing so, the brightness of the Cinema HD can be taken to the maximum and that sets the brightness when reconnecting to the newer M1 Mac.

Sounds a little far fetched but at this point, I'm running out of options!

BRB

I called apple and they say that the Apple Displays are classic products and it doesn't have support to new MacOs. WHAT?