If your getting signal to one tv, you should get the same signal to all. In doing some upgrades to mine, I removed the booster from where it was mounted in the front wall. Right behind it is a splitter that sent signal to all 3 TV's. one of the cables was so loose, it fell out of it's connection to the splitter as I was working on it.
I would check there first, see if the cable connection in the splitter is loose, or disconnected. on my unit, the input cable/antenna connection is made there, and signal is sent to all TV's from that point, there are no other junctions in the RV.
If that doesn't work, check each cable connection at the tv, remove the cable plate from the wall and make sure it's secure in the connection.
