Your Voyager RV Backup Camera Monitor AOM562A has actually been discontinued, and it's replacement parts are no longer available.
I know you mentioned that the other parts work fine, and they are all screwed together, however the best approach is a whole new system.
I know it is not ideal, however seeing as though replacement parts are not offered anymore this is the best option.
If you're interested, check out the:
-Voyager WiSight 2.0 Wireless RV Backup Camera System w/ Night Vision... view full answer...