I'm not sure what to do. I have a 5K iMac and a non-Thunderbolt display connected. However, the secondary display, I cannot control the brightness. In System Preferences > Displays, there isn't a slider for brightness for the secondary display.
I've tried Control/Option/Command/FN + F1/F2 and it won't do it.
Any ideas?
I've tried Control/Option/Command/FN + F1/F2 and it won't do it.
Any ideas?