OTA HD stations. Since one of my sets is not Samsung and it does it too, this seems to be the norm for free HD.
I get the picture on each channel, but at random and almost as a computer virus on a computer, I am loosing sound on channels- one by one and randomly each time I choose a channel. It started with one a few days ago, and each time I turn the TV on, I loose sound on another one. I have never owned a television that gave me any problems in the past or present, and this problem is very puzzling!