Link for Known Outage:
Assuming the cables are all connected ,typically, a “Hard Reset” will fix the issue with any Audio or Video. Simply unplug the Directv box from the unit itself, NOT FROM THE WALL, wait 2 minutes and plug back in.
If that is not your issue or does not resolve the issue, check out this great resource on their website. Call us first before you sit on hold with them!
Directv Troubleshooting Videos: