I just bought a QX56 and when reverse is engaged the screen changes to the "look behind you before whatever" screen but no image shows for the camera, also no indication lines just black screen.

I have done my research and everything points to the Camera control module. Great easy fix...
I checked the fuses none are blown.
I put the nav screen in the diagnostic mode "settings and counter clock wise on the volume knob" it reported the camera was working fine.
I measured the voltage and the power and Acc pins both of them are getting around 13-15v

So I bought a replacement used "working" module. However in my excitement i did not notice it is slightly different only in model number. I went ahead and swapped them anyway. I still did not fix my issue. It does the exact same thing. Black screen no indication lines. Diag reports no problems.

The original module is model EN-1201H-D
The replace module is model EN-1201H

I opened them both up electrical component wise they look identical. I thought about the swapping the EPROM chips around on them from the orignal to the replacement incase there is a different software version or something. Am I chasing my tail here. What else could it be. Should I just find the EXACT replacement and reorder the stupid thing. Thanks for taking a look sorry a little long winded.

typically if you see the guide lines and the "please watch behind you..." sentence on screen it points to the camera, and if nothing is shown, that points to the CCU.

nissan updates their parts just like any other manufacturer, so there will be a slight difference in numbering.

you say "I put the nav screen in the diagnostic mode "settings and counter clock wise on the volume knob" it reported the camera was working fine. "

does this mean you SEE an image??

did you check obd port for any trouble codes?

did you physically LOOK at the camera to see if there is anything blocking the sensor?

do the backup sensors work?

which model year did you buy? did you know this camera issue was present when purchased? did you buy from 3rd party lot? private party? nissan certified?

extreme rare case its a BCM or TCM fault (highly unlikely but want to mention since those parts play a part in all this).