Since I need to work form home at this moment, I have connected an external display. It works great and I now have a far better overview than I had on my tiny MacBook Pro screen. Now I have connected a USB-keyboard and a wireless mouse, so I would like to close my MacBook’s lid while I’m working on the external display. But, somehow, every time I close my MacBook’s lid, the connection to the display is lost and the display goes black…
What is going on ?
To prevent your battery from draining while you are not using your MacBook, all connections are cut off when the lid is closed (since you cannot access the keyboard or the screen when the lid is closed). This also means that the connection to your external display will be cut off whenever you close your MacBook’s lid.
However : since your MacBook’s battery will no drain as long as extra power is provided, this shut down feature will not be activated as long as your MacBook is plugged into the wall charger. So, there’s your answer : just plug your MacBook into external power, and your external display will not go black when you close the MacBook’s lid.
Note : if you already have your MacBook connected to external power and your external display still goes black, see this post.
That’s it !