This is a tough one for me as I don't have the best tools to sort video problems. Most of us don't!
But there are some things which we can look at, with a whole range of problems getting to the right parts.
There is some info posted but we start with a conflict on what model you may have. There appears to be no 24D??? Possibly 24G?
I went with that idea as they may be near the same on this item. But be aware it may be wrong, if I'm looking at teh wrong RV!
The rear camera is one part we can often get to much easier, os perhaps a look there for any connection that might be loose?
Then it gets tough to get to the connections in the dash. There is a video switch that looks down and behind the radio? That seems a place to look for look connections!
Click this snip for better view.
For the switch this shows location behind radio.
There are connections there to check. Several are plugs that have been known to come loose!
this is the drawing schematic for this section that shows the wiring in a different form.
https://www.winnebago.com/Files/File...ire_187480.pdf
Sheets 6 and 7 seem to be the important ones but there are options involved that depend on what equipment was ordered on your specific RV, so some looking at what you have to find what drawing matches will be needed!
Best of luck as it is a tough one to get under the dash and really get a look at what migh have gone wrong!