If your external display is not made by Apple, you might need to use its built-in controls and menu system to adjust brightness. Or choose Apple menu  > System Settings (or System Preferences), then click Displays and use the brightness control there.

If your keyboard and external display are made by Apple, you can use the Brightness Up key on the keyboard to increase brightness. If your external display is dark, make sure that its brightness hasn't been turned down. Learn more about allowing accessories to connect to Mac laptop computers. If you don't allow it to connect, your display remains dark. When connecting a display to a Mac laptop computer with Apple silicon, your Mac might ask you to allow this accessory (your display) to connect. Then press and release the power button to turn it back on. If you can't restart your Mac, press and hold its power button for about 10 seconds to turn it off. Press and hold the Option key to show the Detect Displays button, then click the button. On Mac laptop computers, you can close the lid for a few seconds, then open the lid again.Ĭhoose Apple menu  > System Settings (or System Preferences), then click Displays. It might help to turn off the display first. Use one or more of these steps to try again to detect your display.ĭisconnect the display from your Mac, then reconnect it. If your Mac can't detect your external display, your external display will be dark. To find out how many external displays your Mac supports, and at which resolutions and refresh rates, check the specifications for your Mac model: Learn what to do if your screen became dark after you changed its resolution or refresh rate. This limit varies by Mac model, display, the video cable and adapter used with the display, and the resolution and refresh rate of other connected displays. Your external display will be dark or use a lower resolution or refresh rate if you configure it to exceed the maximum supported resolution or refresh rate. Your external display will be dark if it exceeds the maximum number of external displays that your Mac can use at the same time.

If your display is connected to a hub or dock, connect your display to a port directly on your Mac. If the display is connected to a Mac laptop computer with a closed lid, make sure that the Mac is connected to power and using an external keyboard and mouse. If you're using a Thunderbolt or USB-C adapter, it must also be compliant with DisplayPort Alt Mode, Thunderbolt 3, or Thunderbolt 4. Your external display will be dark or use a lower resolution or refresh rate if your video cable or any adapter you may be using with it doesn't support the resolution and refresh rate of the display. Learn more about how to connect a display to your Mac. Make sure that your external display's power cable and video cable are connected securely and correctly at both ends. If your Mac is working, but the external display connected to it has a blank or black screen (no video) or can't use its highest resolutions or refresh rates, try these solutions. If your external display is dark or low resolution

Best 32 inch 4k monitor for macbook pro