Our unit, that we picked up in early October of this year, has an HDMI "splitter" (?). I believe that is how the signal gets to all 3 TV's. The HDMI controller has 4 ports, but only 3 are used. I feel that is the main cabin TV, the bedroom TV and the outside TV. I think I have all ready over extended my knowledge base. Just what I know. ;-) At this time.
Ric and Jan Golding
2016 Jayco Seneca 37FS