Camera is not working on MacBook Pro

I searched all possible solutions to turn on the internal camera on my MacBook Pro: MacBook Pro (Retina, 13-inch, Late 2013).

• FaceTime is not able to connect the camera.

• Photo Booth is not able to connect to camera.

• Check on System Hardware, camera is not found

• Try to kill VDCAssistant/AppleCameraAssistant, no matching processes are found, unable to find processes in Active Monitor either.

What are the other methods that I can diagnose the camera issues?

Is my internal camera faulty?

How do I activate my camera on FaceTime and Photo Booth?