11-29-2013 05:06:10 AM
On the standard remote, the mute button is immediately adjacent to the volume button--is it possible that you accidentally pressed the mute button when lowering the volume? Try pressing the mute button intentionally to see if your sound comes back. If not, and you have alreaady tried rebooting, then your next step would be to call technical support at 1-800-288-2020.
11-29-2013 09:12:37 AM
Just checking up on your post. I noticed that Docbombay offered some helpful suggestions to help resolve this issue. Were you able to restore the sound on your TV?
If it is still not working then I would recommend using the built-in Troubleshoot & Resolve app on the TV Receiver. On your remote select Menu>> Help>> Troubleshoot & Resolve>> Sound issues. Doing this will cause the box to perform a self-diagnostic and correct any bugs that may be causing this sound issue. Let us know if this helps! Thank you
12-04-2013 04:44:11 AM
Note: after this the remote will not control TV on/off till reprogrammed for your tv.
Resetting the U-verse remote control to factory settings
Follow these easy steps to reset your remote control to factory settings:
1. Press and hold the AT&T key on the remote control.
2. Without releasing the AT&T key, press and hold the OK key.
3. Release both the AT&T key and the OK key. All four mode keys will flash twice to indicate programming mode.
4. Enter programming code 900 by pressing the number keys on the remote control. The AT&T key will flash three times indicating the code was successfully entered and the remote has been reset to the default settings.
Now depress volume up button, sound should be unmuted, turn up to 25 (max output from receiver).
To reprogram remote for TV consult http://www.youtube.com/watch?v=-xM6oEVtLSA&feature