Can't adjust Apple Cinema Display brightness after waking from sleep

[Gobias]

I have a 23" Apple Cinema HD Display, and for a little while now, I've been having an issue where I can't adjust the display's brightness after waking from sleep. When I try to use the brightness buttons on my Logitech K750 keyboard, the brightness meter pops up, but the brightness doesn't change. Also, if I go to System Preferences, the brightness slider does nothing. I can still adjust the brightness using the buttons on the side of the display, but not via keyboard or System Preferences. If I restart my computer, then everything works fine again.

This was only happening occasionally, but recently it started happening every time I woke up my computer. In the past week, I updated from macOS 10.14.3 to 10.14.4 and also replaced my GTX 660 graphics card with an RX 580. I don't know if either of those might have made an impact on the frequency of this issue.

Does anyone have any idea what might be going on?

 

[fk2106]

I have the exact same issue with the 27" Apple LED Display.

 

[zzz1991]

I have this issue too with the 27" Apple LED Display.

 

[rwebb]

I have this issue too with the 27" Apple LED Display.

Try "sudo killall corebrightnessd" from the terminal.

 

[zzz1991]

Try "sudo killall corebrightnessd" from the terminal.

It works, but now this command needs after each awakening. Globally, the problem does not solve, but I can create a service in automator. What ultimately causes the problem?

 

[rwebb]

It works, but now this command needs after each awakening. Globally, the problem does not solve, but I can create a service in automator. What ultimately causes the problem?

I discovered it by looking at Activity Monitor for anything with brightness in the name. I never looked farther than that. My guess is has something to do with the new nightshift feature. I noticed killing corebrightnessd causes nightshift to go to the daylight setting.

I made a shellscript that checks the time of day and sets the nightshift level after killing corebrightnessd. I trigger it with an applescript app I put in my finder window toolbar. I originally intended to track down the source of the problem but this workaround demonstrated that I rarely change monitor brightness.

 

[zzz1991]

I discovered it by looking at Activity Monitor for anything with brightness in the name. I never looked farther than that. My guess is has something to do with the new nightshift feature. I noticed killing corebrightnessd causes nightshift to go to the daylight setting.

I made a shellscript that checks the time of day and sets the nightshift level after killing corebrightnessd. I trigger it with an applescript app I put in my finder window toolbar. I originally intended to track down the source of the problem but this workaround demonstrated that I rarely change monitor brightness.

I have a problem. All USB ports stop working for 1 second on a short time after waking up. After this, USB (including bluetooth) is reconnected. I'm still trying to fix usb. I made a patch in Clover for a limit of 15 ports and USBInjectALL.kext. Now all USB ports work (even charging Ipad while the computer is sleeping), but the problem with the reconnection has not gone. I think the problem with the ports is related to the brightness.

 

[Gobias]

Try "sudo killall corebrightnessd" from the terminal.

I discovered it by looking at Activity Monitor for anything with brightness in the name. I never looked farther than that. My guess is has something to do with the new nightshift feature. I noticed killing corebrightnessd causes nightshift to go to the daylight setting.

Running a sudo command every time I wake my computer isn't really practical for me since I don't use an admin account for day-to-day stuff, so I'd have to go through the extra step of logging in to my admin account.

However, I can confirm that killing corebrightnessd via Activity Monitor does temporarily fix the issue.

I don't use nightshift, but I do use f.lux. I don't know if that has any impact. I'll experiment with quitting f.lux before putting my computer to sleep to see if it makes any difference.

 

[rwebb]

Running a sudo command every time I wake my computer isn't really practical for me since I don't use an admin account for day-to-day stuff, so I'd have to go through the extra step of logging in to my admin account.

However, I can confirm that killing corebrightnessd via Activity Monitor does temporarily fix the issue.

I don't use nightshift, but I do use f.lux. I don't know if that has any impact. I'll experiment with quitting f.lux before putting my computer to sleep to see if it makes any difference.

I'm sure this is the wrong way to approach the problem, but I made it run without sudo.

I set up a shell script that runs as root. Now I just click on an app that triggers the shell script. The script has to be put in the right place in the system, set as owned by root wheel and then added to a specific file to be run without a password. It's been long enough that I don't remember all the steps. I googled and found how to run a shell script without sudo on a Linux forum. Be sure to read about the security implications if you choose to do this.

This was supposed to be a temporary solution, but once I set it up, finding the actual root of the issue became less important.

 

[tilleynj]

I have the same issue-- 10.14.4 on 2015 rMBP 15" with 30" Cinema HD 2560x1600 display connected via mini DisplayPort. using machine in clamshell mode. i have the landingzone pro dock. Fresh boot -- everything is great (really -- i love this old display)

Every morning i come in to the office, connect to the dock in clamshell mode having manually put the machine to sleep about 14 hours prior and wake it using mouse (bluetooth or USB makes no difference). I hate opening the laptop because i do run parallels and i can't find the right setting to use both retina display and cinema display without going blind or tearing out my eyeballs. I *think* since the .4 update, i've been having the issue with cinema display being at the lowest brightness after wake from sleep and my only recourse to be a reboot.

Enabling / disabling night shift had no effect and neither the sudo command nor force stop from activity monitor for corebrightnessd have any impact for me.

i did notice that if i'm persistent on my keyboard, i can not only get the brightness OSD to appear, but pressing the key fast enough, i can get two or three bars to appear before it adjusts itself away.

For me, I discovered the slider in system preferences DOES change the brightness, but it just dims itself again to the lowest brightness, and the slider (only) moves itself down to about 10% lower than wherever i drop it).

I figured it must be adjusting brightness using webcam as ambient light sensor (either the usb one i have on cinema display or the one that is on the laptop display (which again is in clamshell, so 'dark' would be appropriate if that's what it's doing)

i can't reboot right now, but if it could, I'd disconnect from the dock, reboot, turn off auto-brightness on the laptop itself, reboot again, connect to the dock, reboot in clamshell and see if that has any impact to clamshell sleep/wake. I did open the laptop and toggle the setting for auto-brightness on the native display with no impact.

I feel like when waking from sleep in clamshell, the cinema display is recognized as the 'native' display and for whatever reason inherits the auto brightness setting, but doesn't expose that setting in the systems preferences pane to disable it.

This behavior is constant UNTIL I DISABLE THE BUTTONS ON THE DISPLAY under the 'options' tab. now it does let me set (and keep) the brightness in the system preference display panel (display tab). This also disables the buttons on my keyboard. When I re-enable the ability to adjust brightness like a normal person (from the display or from the keyboard) the problem returns.

I was genuinely surprised to see night shift working on the external display -- it doesn't work with my other (non-apple) displays, so I would bet that their attempt to be 'fancy' and include the 15 year old cinema displays in their new feature is a little... buggy.

i'm not really concerned with the cause, but would encourage you all to report it to apple so WE don't have to each come up with our own solutions, but it eventually is fixed for us.

i hope the disabling of the on-display brightness buttons helps you.