Chosen Solution
So my ambient light sensor changes keyboard brightness and so do the f keys, but my screen brightness doesn’t change, the f keys don’t work…and there is no setting to change it in System Preferences! help!
This sounds like you have a messed up keyboard. Did you have a liquid spill at some point? Just in case you don’t know here’s the user guide info on the Fn keys:
When you use the brightness control buttons you should see a icon on your screen which visually shows you the level. Update (08/04/2020) @mercutio999 - Its not! The control via the Fn keys maybe they aren’t working. Lets backup here… You are seeing the controls them selves both on the Screen and Prefs for setting? So its not seeing the control its the fact the screen is not altering, then the backlight logic has a problem! Your Displays control panel also has a slider which you can use to adjust the screen brightness. Do you even see the control?
I have the exact same issue. I have no issue with any other keys on my keyboard, and I’ve never spilled anything on it. Here are what I’ve looked at so far: -F1 and F2 keys do not work: System Pref > Keyboard > “Use F1, F2, etc as standard function keys..” BOX CHECKED -No Brightness scale bar in Displays > Display/Color/Night Shift
I’ve got the same issue on my mbp. Also my video out signal doesn’t work.
