Turn off the built-in monitor on MBP El Capitan with clamshell open [duplicate]

Solution 1:

You can also just mirror the display of the MacBook screen to the external one and then turn off the brightness of the Macbook screen (so it turns fully black). Then you can keep the lid open of your MacBook AND use the TrackPad.

System Preferences > Displays > Arrangement > Select "Mirror Displays".

Solution 2:

Given how none of the old methods seemed to work in El Capitan, the magnet method sounded pretty interesting to me, so I decided to try it.

I got the smallest and weakest hobby/craft magnet I had, and ran it through the top left corner of the Macbook Air, as some of those other answers said that's the location. I suspect the location may differ between Macbook models.

In my MacBook Air (13-inch, Mid 2012), the location seemed to be on the left side, slightly above the Tab key.

I used Pritt multi tack to keep the magnet in place, but you could use double sided tape, for example. If I wanted to be really careful with the magnet, I could've put a spacer between the Macbook surface and the magnet about the height of the magnet itself, and it still would've worked.

There's one kinda big downside to this.

• If you stop using the Macbook touchpad or keyboard for something like 3 seconds, they stop working. You then need to remove the magnet to re-enable them. This is kind of a deal-breaker, if you don't want to use external mouse and keyboard.

If you are ok with using an external keyboard and mouse, this seems like the best method to me.