I have lost sound on one network channel and it's HD channel. My second box is fine. After doing some useless attempts to fix the problem by talking to a Comcast rep I wonder if anyone's had this problem. I unplugged the thing. I unplugged the cables behind it. The rep supposedly sent signals to it twice. I was then told it was the TV network. Nope. The other box is fine! So I was told I need a new box. I don't know much but I know that's not the problem. I have no other problems with other channels. Any help is appreciated.