DDC and Monitor Inputs Troubleshoot hardware commands, monitor input switching and DDC communication. Explore subtopics Separate articles that explore this topic in more detail. Why can I switch monitor inputs but not switch back?Input switching depends on both the monitor’s command support and whether it accepts commands from the connection sending them. Why is Input Source missing even though my monitor’s brightness control works?Input selection is a separate DDC feature. Why is DDC disabled for my Apple Cinema Display when another app can use it?BetterDisplay treats Apple displays differently and can deliberately withhold DDC control to avoid brightness problems. Why does hardware brightness work directly but fail through a dock?A dock can carry the display image while its DDC control path behaves differently from a direct connection. Why does a brightness query return a different value from the monitor’s own menu?A hardwareBrightness query returns BetterDisplay's managed, normalized brightness value. What can I do if the monitor’s own menu stops opening after a DDC power command?Stop repeating the power or backlight command and use the monitor manufacturer's recovery guidance. Why does an input named HDMI switch my monitor to USB-C?The default input names represent common DDC assignments. Why does my monitor stay dim or tinted after changing DDC RGB gain?Check that the configured RGB gain range matches your monitor. Where is hardware contrast, and how can I change it from Shortcuts?Look under App Menu > [display] > Device Control for hardware contrast.