So I'm left guessing the source of live TV.
Recheck the connections for live TV and for that source, try it on another TV.
Oldish samsung plasma TV will play sound but not picture for live TV, but will play picture for DVR'ed programs. This all occurred after the people who are buying our house had their walkthrough and asked about the TV mount. I think they may have disrupted a cable, but cant figure how that would not affect the picture from DVR. Any ideas?

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