Perhaps your projection mode was inadvertently changed. Press the Windows key and the P key to open the Projection menu. Select your desired option: If you want the external monitor to mirror your laptop screen, select Duplicate. If you want one large virtual screen, where external monitor and laptop screen each has its own space, select Extend. If that doesn't work, go to Settings | System | Display | Advanced display settings | and check the various options there.
As of yesterday, my laptop and external monitor were playing nicely - I had two lovely screen to accomplish my video editing tasks. Last night, I disconnected my laptop from the second monitor, took it into another roop to use it, and then reconnected it this morning. When I turned my laptop on, my laptop screen remained black, with everything showing up on the second monitor (attached via HDMI cable). I tried disconnecting everything and rebooting, to no avail. If you have had this issue and fixed it, how did you accomplish this feat? I have an Inspiron 7702 2-in-1. Processor: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz, 2803 Mhz, 4 Core(s), 8 Logical Processor(s) operating Microsoft Windows 10 Home.
Laptop Screen Goes Black When Second Monitor is Plugged In