Loss of audio on one TV when using Sat

[jtking]

Hi all,
We have 2008 Tour Master model 40A and recently we have no sound on Number 2 TV (the one that comes up from from the cabinet behind the passenger seat) when using input from the sat dish. Regular TV, cable, and DVD player all work fine and other 3 TVs have sound on Sat. All wire connections on TV, and the control box and panel above the windshield are tight. Has anyone had a similar problem with solution?? Or any trouble shooting suggestions.

Thanks for any thoughts,

John