You lost the sound on one channel?

I beleive it is the converter box. Is it a "Insignia" or "Magnivox"?I have found that some converters loose some functions, sound being one, if they have

trouble locking to a channel.

If you have more than one converter and one has sound and another does not

that would indicate tge converter has a problem. Weak signal, is generally the culprit.

Here are some things to try.

1. Unplug converter from the wall for 5-10 min then plug it back in and turn it on.

See if that will reset box and recover the original programing..

2. Second option is to DELETE the affectred channel from the converter and re-scan.

This can be a real pain depending on how good the instruction manual is.