Hi : Check it out,.! Some of the reasons, why screen cameras
go black. are described below. Also apply the fixes psoted
Loss of power is a common reason behind, security camera screens
going black. For instance, the power adapter might be disconnected
and the cable connecting, camera to the recorder and monitor may
become faulty. To fix this issue, inspect the power cables
to confirm there's : No damage or disconnection.
How to Fix Your Webcam : Showing a Black Screen on Windows
Start With Generic Fixes.
check the. Webcam Hardware and Connections.
Restart the Computer.
Update Webcam Drivers.
Roll Back Drivers.
Reinstall Webcam Drivers.
check App Permissions.
Scan for Malicious Programs.
Some of the fixes listed above. Are explained in this video
intended for Wins 10 users. which Wins OS is yours, we don't know
-- Don't click or subscribe to anything, shown on the video
How To Fix WebCam Black Screen On Windows 10 (youtube.com)