I recently update my m1 MacBook air to Big Sur 11.2.1.
Now I can't adjust the brightness, and I can't select the monitor as the audio output.
I already tried:
but still not getting it back to normal.
MacBook Air
Hi redonejay,
Welcome to the Apple Support Communities!
We understand that you're unable to adjust the display brightness on your LG monitor that's connected to your MacBook Air. Check out the additional troubleshooting steps outlined here to help isolate this behavior further: Get help with video issues on external displays connected to your Mac
We hope this helps.
Take care!
Thanks for letting us know, redonejay,
What happened when you started your Mac in safe mode?
Does your display have any built-in controls to adjust the brightness?
We look forward to your reply.
Cheers!
Got it, redonejay,
Since you're still experiencing the same behavior in safe mode, we'd recommend that you reach out to LG directly to investigate this further with you. They'd be best suited to help. You can find their contact details here: LG Support
Kind regards.
Hi hermanau,
I was able to use the controls when using Big Sur 11.0 and 11.1, but after I update to 11.2, I lose the controls and stay at this stage till now. If you did nothing on your LG display but the situation changes, I guess this is an Apple problem that we have to get Support from Apple and hope they will fix the problem in later OS updates. :(
This is actually an problem from Apple instead of LG that seems to affect the M1 Macs. I've gone from the controls not available, to being okay with the controls and being able to adjust after the last patch, to now the controls available but not doing anything at all.
Hi,
Under safe mode, the behavior is the same.
For LG ultrafine 5k display, 27MD5KL-B, there are no buttons to adjust the brightness.
Previously, I could adjust the brightness from System preferences -> display -> LG ultrafine display, There is a slider to adjust the brightness, or shortcut: control + F1/F2.
Now the slider disappeared and the shortcut is not working even under safe mode.
Thanks!
Hi ryane77,
I have gone through the page that you provided. The problem is not fixed.
The only thing I didn't try is resetting the SMC and NVRAM, but I think there is no SMC and NVRAM reset for an m1 mac.
This is my monitor model if it helps: 27MD5KL-B.
Thanks!
See the funny thing is after I posted this, now the control is there and it is adjusting the brightness fine... This thing is mind boggling and got a mind of its own. It may or may not work after it goes to screen saver / sleep. This morning when I tried to wake the system the LG 5K is recognized but has no image while the backlight was on. It just want to do something new every single time I use the system.
Can't adjust brightness and no audio for LG ultrafine 5k display with m1 macbook air
