It's not fun to learn that all this is new and the bugs still being worked out. Ask Sharp if there is new firmware for the TV.
Bob
Last year I purchased a Sharp LC40E67U/N 40-Inch 1080p LCD HDTV. We use a basic indoor antenna connected directly to the coaxial connector on the back of the TV. On a fairly regular basis, the audio drops out and stays out unless we change the channel. Once we return to the channel the sound dropped out on, the audio is normal.
The support service for the store we purchased the TV from believes that it's a signal issue. I would understand this if the audio dropped in and out but this seems odd since it drops out and stays out.

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