-Click on Hot Corners and click on one of the corners. Once selected, pull down the menu next to it and choose Put Display To Sleep. Connect the external display to your MacBook and then move your mouse to the corner you selected above. It should turn off only the internal display.
Disable your Mac's display with Hot Corners Open System Preferences and click on Desktop & Screen Saver. Select the Screen Saver tab, then you should see a button marked Hot Corners… under the main pane. Click this and you'll see a mini window appear with drop-down menus for each corner.
Technique #1: Power Options Inside the Control Panel settings, Power Options is available and helps you to switch off the laptop screen while an external monitor is attached to it. What is this? Part 2) Open the Control Panel, and click on the Hardware & Sound setting, and choose Power Options.
If so, here's how you enable it:
To do this, simply follow these steps:
Connect the external monitor to your Mac and ensure that it's turned on. Click on the Apple menu and go to System Preferences. Select Displays and go to the Arrangement tab. Ensure that the Mirror Displays checkbox is unchecked.
No. Using an external monitor or leaving the computer plugged in will not damage the computer or the battery. Leaving the computer plugged in reduces the rate of accumulation of battery cycles.
This is how I achieve this.
Set sleep and wake settings for your Mac
Mac. On a Mac, this is called Clamshell mode. To turn it on, open the Apple menu and navigate to System Preferences > Energy Saver, and set the Computer Sleep and Display Sleep sliders to Never.
Connect an HDMI display or HDTV: Plug a cable from your HDMI display or HDTV directly into the HDMI port on your 14-inch or 16-inch MacBook Pro. Use a USB-C Digital AV Multiport Adapter to connect the HDMI display or HDTV to a Thunderbolt / USB 4 port on your 13-inch MacBook Pro13-inch MacBook ProApple 60W MagSafe 2 Power Adapter (MacBook Pro with 13-inch Retina display).
Honorable. Right click anywhere on the desktop, click screen resolution. Click on the display you want to turn off. In the Multiple displays drop box, choose "disconnect this display".
You can use an external display such as the Apple Studio Display, a projector, or an HDTV with your MacBook Pro. The HDMI and Thunderbolt ports on your 14-inch and 16-inch MacBook Pro support video output.
This makes it possible for supported Macs to use another Mac as an external display, and with AirPlay to Mac working both wirelessly or with a wired connection, Apple has come close to reviving Target Display Mode, which allowed 2009 to 2014 iMac models to serve as another Mac's external display.