Why is my backup camera just a black screen?
The most logical explanation is that the camera is not powered, instead of just being ineffectively connected. For troubleshooting a black screen on a backup camera, check the wiring diagram of the car and the backup camera, which is usually on the manual provided by the manufacturer or supplier.
Why does my reverse camera say no video signal?
This can be related to 2 different things: Missing 12V power at the camera. Measure the cam connection for ground and +12V if your reverse gear is activated. If there is missing something, you need to follow the cable and check the connections.