Can't stop auto dim brightness

[Sach160]

Hi all, I have a completely unimportant but deeply annoying issue that is taking up way too much of my mental space. Hoping some mac genius can assist! I'm on a MacBook Pro (14 inch 2021) Monterey 12.6.

The screen auto dims by half whenever unplugged from the battery. Under system preferences, battery I have 'slightly dim...' unchecked. Under system preferences, display, I have 'automatically adjust brightness' off and 'true tone' off.

I tried restarting in safe mode and it happens there too. Is this happening to anyone else? Is it a bug?

 

[usagora]

So I'm assuming you have tried manually adjusting the brightness back up to the level it was before you unplugged the power cord? If so, does it change at all when you plug in the power cord again? And then when you unplug the power cord again does it go back down to the same level it did before you manually increased it?

I'm just wondering if the system "remembers" the last brightness setting you set when running on battery power.

 

[Sach160]

Hi, when I unplug it dims to half brightness. I then manually adjust it up to full if I then plug it back in nothing changes but when I unplug it again, it dims to half again.

If I don’t adjust it up from half brightness before plugging it back in, it gets a bit brighter - a couple of notches but doesn’t go back to the full brightness it was at before being unplugged.

 

[usagora]

Hi, when I unplug it dims to half brightness. I then manually adjust it up to full if I then plug it back in nothing changes but when I unplug it again, it dims to half again.

If I don’t adjust it up from half brightness before plugging it back in, it gets a bit brighter - a couple of notches but doesn’t go back to the full brightness it was at before being unplugged.

Good to know. I will try to remember to check the settings on my MBA when I get home and see if I can replicate what's happening for you on your MBP.

 

[chown33]

This sounds almost exactly like the 'halfdim' setting available in the 'pmset' command. Here's a man page for it:

pmset Man Page - macOS - SS64.com

ss64.com

halfdim - display sleep will use an intermediate half-brightness state
between full brightness and fully off (value = 0/1)

Note that this setting is distinct from 'lessbright', which is the typical one that dims slightly when on battery.

The first thing to do is find out what your settings are. Do that while it's on battery, so the then-current settings are listed.

Type this command into a Terminal window:

pmset -g

The output will be a bunch of text. Use drag-select to select it all, then copy and paste it into a post here.

EDIT
I'm much less sure it's related to 'halfdim', now that I checked it on an actual laptop. The 'pmset -g' output on my older MacBook Pro shows halfdim is 1, but I don't have it set to dim on battery.

It would still be useful to see the output of the 'pmset -g' command, so please post that.

 

[Sach160]

Hi, thank you so much for assisting. Output attached

 

[appltech]

Hey
If I understood correctly

Turn off "low power mode" on the Battery section

 

[Sach160]

Brilliant! Thank you so much - that worked. I searched the internet for this issue and never found this as suggestion. Thank you again