No 24" Cinema Display Brightness Control Monterey

[uller6]

My 24" LED Cinema Display has been working swell for years. I've been using it with my 24" M1 iMac and it's been great, with full hardware brightness control on Big Sur. Now that I've upgraded to Monterey, I no longer have keyboard brightness control on the Cinema Display! In preferences, there is no brightness slider for the Cinema Display, while there is for the iMac. Also, the maximum brightness appears to be dimmer than the real max.

I've plugged the Cinema Display into my old 2012 Mac mini running 10.15.7, and the display works as it should with correct maximum brightness and full keyboard hardware control, so I'm certain this is a Monterey issue.

Does anyone else have this issue with either this model or other model cinema displays? I hope this is a bug that gets fixed in an update soon!

 

[Amethyst1]

I had the same behaviour with an acrylic (i.e. very old) Cinema Display when I upgraded from 10.8 to 10.9. I had to re-add a few kexts from the older version to restore brightness control. Maybe this is the same issue. Can you take a look at which kexts are loaded/present in Catalina/Big Sur vs Monterey and look for anything suspicious, i.e. any display backlight-related ones that are there in the older version but not in Monterey?

 

[mrowell]

I wouldn't go the kext path. Instead this open source tool allows me change the brightness on the LED Cinema Display and works even better than the native controls - https://github.com/MonitorControl/MonitorControl

 

[uller6]

I did some more experimenting last night. I can replicate the problem with the 24" Cinema Display connected to my M1 MacBook Air (running Monterey) as well. However, connecting the Cinema Display to an 2014 intel Mac mini (running Monterey) works fine with full native backlight control! This seems to be an issue that only effects M1 Macs on Monterey (12.0.1 for now).

Thanks @mrowell for the suggestion. I actually already use Monitor Control and while it allows me to change the external display brightness, for some reason the maximum brightness is limited to 50% of the display's brightness capability. So I can change the brightness from "dim" to "very dim." Without monitor control running then I can't change the Cinema Display backlight brightness at all, which as I said before was working fine in MacOS 11.6.

@Amethyst1 I'm hesitant to try the kext path for now, but if this bug isn't fixed in the next 1-2 releases then I may try that route instead.

 

[r6novak]

I did some more experimenting last night. I can replicate the problem with the 24" Cinema Display connected to my M1 MacBook Air (running Monterey) as well. However, connecting the Cinema Display to an 2014 intel Mac mini (running Monterey) works fine with full native backlight control! This seems to be an issue that only effects M1 Macs on Monterey (12.0.1 for now).

Thanks @mrowell for the suggestion. I actually already use Monitor Control and while it allows me to change the external display brightness, for some reason the maximum brightness is limited to 50% of the display's brightness capability. So I can change the brightness from "dim" to "very dim." Without monitor control running then I can't change the Cinema Display backlight brightness at all, which as I said before was working fine in MacOS 11.6.

@Amethyst1 I'm hesitant to try the kext path for now, but if this bug isn't fixed in the next 1-2 releases then I may try that route instead.

I am having the same issue with my 27 LED Cinema Display. Brightness worked well with 11.6 but in OS12 it will not work.

I had the 50% brightness issue too. What I did was plugged it into a Intel Mac that the the brightness still works on and maxed it out. Then when I moved it to my M1 Mac mini it would still be on Max. that what when I use these eternal brightness controls they work at max=max and min=min. I did this because when I used one of the third part display brightness controls it would always "think" the first plug in was the default max brightness.

UPDATE*** it still just made the default brightness very dim. What I did was max it back out and downloaded Brightness slider from the App Store. Its not great as its made for older monitors but its doing the trick until its fixed.

I even reinstalled OS12 because I thought maybe something went wrong. But nope it seems to just be a bug with the M1 Macs.

(Brightness works with my Thunderbolt version although I get a flicker every now and then. I much prefer the LED cinema displays personally)

 

[xraydoc]

I wouldn't go the kext path. Instead this open source tool allows me change the brightness on the LED Cinema Display and works even better than the native controls - https://github.com/MonitorControl/MonitorControl

This works great for controlling the brightness on my Dell UP3216Q from my external keyboard. Allows me to control the brightness from the keyboard's brightness keys. No issues on macOS 12 as far as I can tell.

The app is also M1-native. Nice bonus.

 

[r6novak]

This works great for controlling the brightness on my Dell UP3216Q from my external keyboard. Allows me to control the brightness from the keyboard's brightness keys. No issues on macOS 12 as far as I can tell.

The app is also M1-native. Nice bonus.

When I tried it, it halted my brightness as soon as the app started. Treating the 50% as if it was 100%. could not get it to change that. Im using the LED Cinema Display 27". Any ideas?

 

[4sallypat]

I did some more experimenting last night. I can replicate the problem with the 24" Cinema Display connected to my M1 MacBook Air (running Monterey) as well. However, connecting the Cinema Display to an 2014 intel Mac mini (running Monterey) works fine with full native backlight control! This seems to be an issue that only effects M1 Macs on Monterey (12.0.1 for now).

Thanks @mrowell for the suggestion. I actually already use Monitor Control and while it allows me to change the external display brightness, for some reason the maximum brightness is limited to 50% of the display's brightness capability. So I can change the brightness from "dim" to "very dim." Without monitor control running then I can't change the Cinema Display backlight brightness at all, which as I said before was working fine in MacOS 11.6.

@Amethyst1 I'm hesitant to try the kext path for now, but if this bug isn't fixed in the next 1-2 releases then I may try that route instead.

So M1 and Monterey is an issue with ACD only ?

Haven't upgraded to Monterey yet as our work organization has not approved it yet as we have to vet all apps, extensions, addons, and retain security under our MDM.

BTW:
Anyone know if the 27" Thunderbolt display suffers from the same brightness issue ?

 

[uller6]

Right, M1 + Monterey seems to have an issue with both 24" ACD and 27" ACDs, but status of the 27" thunderbolt displays is unknown - can anyone confirm their 27" TBD working/nonworking with Monterey + M1?

 

[r6novak]

Right, M1 + Monterey seems to have an issue with both 24" ACD and 27" ACDs, but status of the 27" thunderbolt displays is unknown - can anyone confirm their 27" TBD working/nonworking with Monterey + M1?

On my M1 mini the thunderbolt display brightness control works but it does flicker every now and then. Does not do that on any other Intel Mac I own.

 

[leoluzacmp]

Same problem here. 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.

 

[flyabb]

Solution: A solution to the dimming problem and regaining control over the full brightness range of the LED Cinema Display on M1 Macs running macOS Monterey is to use the MonitorControl app (latest version 4) and then toggle the advanced settings on the Display tab with a custom max DDC value of 255. Make sure you turn off the software dimming option too (General tab) and use the hardware DDC setting. This restores the brightness controls over the full brightness range as before. The default keyboard shortcuts also work.

See this post for more information/background: MonitorControl GitHub At the bottom of that thread are some screenshots with the required settings. I use a DDC setting of 255 instead of 250.

I found that the max DDC of the 27” LED Cinema Display is 255, increasing the DDC value above that will not result in a proper max brightness. Setting a lower value (by default 100) results in a max brightness of 39%, hence why the display dims initially when using the MonitorControl tool without the advanced setting set. You can try different values to test it out.

I am using a M1 Mac mini with a 27” LED Cinema Display (using a USB-C to mini DisplayPort converter and the USB-A connector of the display also connected to the Mac).

Your welcome!

 

[leoluzacmp]

Solution: A solution to the dimming problem and regaining control over the full brightness range of the LED Cinema Display on M1 Macs running macOS Monterey is to use the MonitorControl app (latest version 4) and then toggle the advanced settings on the Display tab with a custom max DDC value of 255. Make sure you turn off the software dimming option too (General tab) and use the hardware DDC setting. This restores the brightness controls over the full brightness range as before. The default keyboard shortcuts also work.

See this post for more information/background: MonitorControl GitHub At the bottom of that thread are some screenshots with the required settings. I use a DDC setting of 255 instead of 250.

I found that the max DDC of the 27” LED Cinema Display is 255, increasing the DDC value above that will not result in a proper max brightness. Setting a lower value (by default 100) results in a max brightness of 39%, hence why the display dims initially when using the MonitorControl tool without the advanced setting set. You can try different values to test it out.

I am using a M1 Mac mini with a 27” LED Cinema Display (using a USB-C to mini DisplayPort converter and the USB-A connector of the display also connected to the Mac).

Your welcome!

Thanks! It worked perfectly for me too (Mac mini M1 + 27" Led Cinema Display via USB-C adapter for mini displayport)

 

[r6novak]

Solution: A solution to the dimming problem and regaining control over the full brightness range of the LED Cinema Display on M1 Macs running macOS Monterey is to use the MonitorControl app (latest version 4) and then toggle the advanced settings on the Display tab with a custom max DDC value of 255. Make sure you turn off the software dimming option too (General tab) and use the hardware DDC setting. This restores the brightness controls over the full brightness range as before. The default keyboard shortcuts also work.

See this post for more information/background: MonitorControl GitHub At the bottom of that thread are some screenshots with the required settings. I use a DDC setting of 255 instead of 250.

I found that the max DDC of the 27” LED Cinema Display is 255, increasing the DDC value above that will not result in a proper max brightness. Setting a lower value (by default 100) results in a max brightness of 39%, hence why the display dims initially when using the MonitorControl tool without the advanced setting set. You can try different values to test it out.

I am using a M1 Mac mini with a 27” LED Cinema Display (using a USB-C to mini DisplayPort converter and the USB-A connector of the display also connected to the Mac).

Your welcome!

Amazing, thank you so much

 

[uller6]

Wow, this is amazing! Thank you @flyabb ! My 24” ACD now has brightness control and correct maximum brightness when connected to my M1 iMac using a Mini DisplayPort to usb c adaptor.

 

[rwwr]

Thank you @flyabb ! It helped a lot!

 

[Ben9783]

Thank you for this perfect solution for brightness control of Apple Cinema Display on MacOS 12.0.1 Monterey.

 

[Ben9783]

I have a second issue on my Apple Cinema Display running Mac OS Monterey 12.0.1: some pixels are disabled at the border just below of the iSight camera. It looks like a thin black line along the border of the display (around 2 centimeters long just below the iSight camera). Does anybody have the same issue? Take a look on the picture which I attached below. Thank you for your answers.
I just noticed that the color of the pixels change, depending on the background color. I added a second screenshot with black background and a white line of pixels... does anybody has any idea what the reason could be? My Cinema Display is connected over Mini Display Port over the choetech adapter, which worked fine on BigSur.

 

[DesertNomad]

I have a 30" Cinema Display hooked to a Mac mini running 12.1 beta. The +/- buttons on the side of the display work, but there is no icon shown on the screen and the keyboard buttons don't work either. It is connected with a USB-C to Mini Display Port and that is connected to the DualLink adapter for the 30".

 

[wesleycacciari]

I called apple and they said the ACD is a Classic Product and it doesn't have support to Monterey (I have M1 MBA). Also, I'm using MonitorControl app with 250 DCC value but I feel like it's not the same.

 

[wesleycacciari]

I have a second issue on my Apple Cinema Display running Mac OS Monterey 12.0.1: some pixels are disabled at the border just below of the iSight camera. It looks like a thin black line along the border of the display (around 2 centimeters long just below the iSight camera). Does anybody have the same issue? Take a look on the picture which I attached below. Thank you for your answers.
I just noticed that the color of the pixels change, depending on the background color. I added a second screenshot with black background and a white line of pixels... does anybody has any idea what the reason could be? My Cinema Display is connected over Mini Display Port over the choetech adapter, which worked fine on BigSur.View attachment 1900048
View attachment 1900018

I have the same problem, but mine its like 5mm

 

[gamma303]

Installed Monterey. It didn't dim my Monitor but i did loose the ability to control it.

Installed the Monitor Control from Github and once installed it immediately dimmed my monitor to roughly 50% and made that the max value (brightest it would get). I started to panic as I had a lot of work to be done. Luckily someones suggestion of plugging the monitor into their old macbook running an older OS (mines running Catalina) was able to control my brightness again.

I found whatever i set it at becomes the set value when I plug it back into my M1 running Monterey. Its a hack but saved the day otherwise i was gonna have to plug in my dell monitor.

Can't wait for this bug to be worked out. I love my Cinema Display.

 

[settimi_]

I have a second issue on my Apple Cinema Display running Mac OS Monterey 12.0.1: some pixels are disabled at the border just below of the iSight camera. It looks like a thin black line along the border of the display (around 2 centimeters long just below the iSight camera). Does anybody have the same issue? Take a look on the picture which I attached below. Thank you for your answers.
I just noticed that the color of the pixels change, depending on the background color. I added a second screenshot with black background and a white line of pixels... does anybody has any idea what the reason could be? My Cinema Display is connected over Mini Display Port over the choetech adapter, which worked fine on BigSur.View attachment 1900048
View attachment 1900018

YES! I've had this issue with my M1 Mini since day 1 on Big Sur! Using a 24" Apple Cinema Display connected with a mini-displayport to USB C adapter. I've noticed the pixels at the top in that region mirror whatever content is being shown in the lower left of the screen, an inch or two from the corner. If you wiggle your cursor down around in that area you'll see it reflected in the stripe of pixels at the top. I've tried more than one adapter, and the issue doesn't appear on an HDMI-connected non-Apple display. I'm probably going to call AppleCare about it soon.

I'm also having the issue with Monterey disabling the ability for me to change brightness on my cinema display. I'm about to try the MonitorControl method again using the settings @flyabb posted, but I really hope this issue is fixed in the next OS update.

 

[EugW]

Arghh. I guess I won't be buying a 24" LED Cinema Display then. Perhaps I will buy a 23" Cinema Display instead, since that's just plain single-link DVI plus USB. The good news is that even if the USB control ceases to work in Monterey or a later macOS, the side brightness buttons will still work. The bad news is that I'll need external audio and external iSight.

I have a 30" Cinema Display hooked to a Mac mini running 12.1 beta. The +/- buttons on the side of the display work, but there is no icon shown on the screen and the keyboard buttons don't work either. It is connected with a USB-C to Mini Display Port and that is connected to the DualLink adapter for the 30".

Did it work in 12.0.1? Which Mac mini? Do you have the USB cable from the 30" Apple Cinema Display (ACD) plugged in? Are you using the Apple mini-DisplayPort to dual link DVI adapter? If so, the USB plug from the ACD's cable needs to be plugged into the USB port on the dual-link adapter, and in turn, the USB plug on the adapter cable needs to be plugged into the Mac mini.

I have a 30" ACD and it works with brightness buttons on my keyboard in Monterey 12.0.1 (not 12.1). I'm using a 2017 12" MacBook, going through a Cable Matters USB-C to USB 2 + DisplayPort + Ethernet multi-function hub --> no-name DisplayPort to mini-DP adapter --> Apple mini-DP to DL-DVI adapter --> 30" ACD. However, very occasionally after waking from sleep, the buttons continue to register but don't actually change the brightness. What happens is if I press the brightness up or down buttons, the icon shows up on screen, but it doesn't budge either direction. To get this to work again, I have to log out and log back in, and then it works again.

However, I'm not sure if it's because of my having to run everything via a third party hub through the MacBook's single USB-C port. Later on I'll try it with a 2014 Mac mini running Monterey, and will plug the USB directly into the Mac mini instead of through a hub. That might be a while though, since I'm waiting for the Mac mini to get delivered from the US to me here in Toronto.

 

[Amethyst1]

Perhaps I will buy a 23" Cinema Display instead, since that's just plain single-link DVI plus USB.

The aluninum ones were known for having a pink tint, so you may have to look for a "good" one.