I get sound but no picture on only 3 HD channels ( 247,248 and 249) on one TV but get both sound and picture on the other TVs. Would it be the older HD receiver I'm using on this TV?
Yes, the new stations are MPEG4, your terminal likely doesn't understand MPEG4 so just gives you the audio, but no picture,
There is a bit more reading here if you are interested,
Guide to MPEG4 Channels and Digital Cable Boxes
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