Reversing camera signal fail message

I have a 2013 Autosleeper Devon (Devon being the name for a Marquis badge of an Autosleeper Stanton). Reverse camera has now this message 'Signal Fail' and is useless. There appears to be no means of access to the camera or the wiring. I haven't had any success with a very good Motorhome repairer who had no joy either in spite of contact with Autosleeper.  I am now faced with doing without it, expensive replacement (mainly labour), or holes being made in the outer skin to access the camera itself.
Has anybody had the same problem

After a lot of careful measurement, cut a hole in the back of the overhead locker and you can then access the camera fixings and its connector. The wood removed for access can be reused as a removable panel.