Legend Television

We have a Legend brand TV in our travel trailer. It is only 3 years old but we have never been able to get any of the inputs to work besides playing a DVD through the Jensen stereo or tv channels through the antenna. When I plug an HDMI in it says no signal for both inputs. Also, originally the inputs were all named wrong. I fixed this though.

Has anyone else had this issue with HDMI inputs not working? We were going to replace it, but I figured I would ask first.