I have a Panasonic CT-32HL15N, but I have the opposite problem. We have video, but no sound. Is there a fuse for that as well? Or is it something else? Thank you very much!

Is this on all inputs? Check the connections also.

To the best of my knowledge there isn't a simple fix to this (like a fuse). It is possible that it is just a lose connection to the speakers, but doubtful (since it isn't just a single speaker). I checked a schematic on Sears' website, but I don't see any specific part that could be causing this. If you feel comfortable you could take it apart and look for any visible problems (popped capacitors, etc). Otherwise a tube TV really isn't worth paying to have fixed.