sometimes when you turn on the dvr, if it was or is recording something the box will be muted. when Comcast installs the box it typically programs the remote to mute your television.
to program your remote for the DVR follow these instructions:
> Just follow these instructions.
> I use the lower right button on our remote.
> Thumbs up 30 Second SKIP, MUTE & SWAP Programming
> Here are the steps to program the 30 Second Skip, Mute, and Swap to the
> 6208/6412 remote.
> 1) Press the "Cable" button at the top of the remote to put it into Cable
> Box control mode.
> 2) Press and hold the "Setup" button until the "Cable" button blinks
> 3) Type in the code 994. The "Cable" button will blink twice
> 4) Press (do not hold) the "Setup" button
> 5) Type in the code 00173 (for 30 second Skip), 00141 (for Mute) or 00236
> (for Swap).
> 6) Press whatever button you want to map the skip, mute, or swap function
I also have the Comcast Motorola 6412 box and have witnessed the sound cutting in and out on the high-definition channels of CBS and NBC. every once and while it will do it on ABC as well but very rarely. seems to do it more frequently with recorded programs than with live television.
A Comcast representative called me the other day and said they are having a lot of trouble with the Motorola box.