I have a cheapo Emerson HDTV in my study with a brand new Dish Network HD box and every once in a while the volume will just go silent like someone put it on mute. It usually occurs after pausing the tv for a few minutes but other times will just go off randomly. I called Dish Network a few weeks ago and they sent me a new box but that hasn't fixed the problem. Could it be that I have another faulty box or is it the tv?