It may have been knocked out by a power outage. If only one channel is rolling, call SusCom. Use TV volume control. Use mute switch on TV, remote control or converter. Unplug converter from wall socket for 15 seconds then plug it back in.
All converters are warm to the touch.
Do not place objects on top of the converter. Remote control not working. Make sure nothing is obstructing the path between the remote and converter. Check batteries in remote control. Picture but no sound.