How can I find the brightness key on my iMac?
The brightness keys on the keyboard do nothing, and when I go to do it manually in Settings, there is bizarrely no brightness slider in the Displays section like there should be. It's as if the computer just lost the ability to change brightness. I even tried Karabiner to map the function onto the brightness keys, and that didn't work. What can I do?
[Re-Titled by Moderator]