Black Screen Mac Os sonoma

it's generally a good practice to restart your Mac after deleting system files, such as "apple.com.Zoom.phlist" or "apple.com.Facetime.phlist," especially if you're experiencing issues like a black screen during Zoom or FaceTime calls. Restarting your Mac allows the system to reset and apply any changes made, which can help ensure that the changes take effect properly. After restarting, check if the problem persists and if the camera behaves as expected in Zoom and FaceTime. I don't have time signout FaceTime on Tuesday I have class attendance. It still black screen,but sometimes it video camera show up since power off/shutdown.