I'm sorry for any miscommunication. The site treats any response (even though this was really only an information request) as an answer, and alerts you as such.
Thank you for the information William.
I was simply trying to confirm that you were consistently getting picture but having trouble with sound.
This tends to indicate an internal tuner defect, meaning the tv is having trouble processing/decoding some of the audio signals. That isn't surprising to see either as a hardware limitation or failure/degradation, for a tv this age. At 10+ years old, this set is already far beyond its expected service life.
There are a few things we can try here.
First, unplug power to the tv for at least an hour, to reset it.
Then, go into the setup menu and run the channel scan function again (auto tune).
If still no change, on the specific channels that were having problems, look for the SAP or MTS button on the tv remote, and press that repeatedly to get to SAP mode turned off.
If still no change, we'd be looking at a hardware problem which would ultimately require repairs to correct. While it can be fixed, it would simply not be practical. Repairs would cost as much as a new tv ($300 range) and parts are not readily available anyway.
A better option in that case, other than replacing the tv completely, would be to connect an external tuner to replace the faulty internal tuner functions: http://amzn.to/1NDKnJp
This is about $30, and would give you access to all the same channels (with full picture/sound) as your other tvs, and even give you some added features like the ability to record (to usb memory/drive) as a dvr.
Best regards, ***** ***** for the news,