One channel only has no sound

SEE IF THE REMOTE HAS AN INPUT BUTTON OR TV/VIDEO

Check and replace its main system memory IC. It is faulty.

Will need to know what tv you have, but you are right it is probably your input button. if you pushed it on your remote then there should be an input button on remote. otherwise you will have to go into the tv menu and setup it up there.
if you respond with model and make of tv, might get more info.

you can lock/unlock above functions by pressing zoom and negative volume control keys simultaneously.

i think by accident you have changed the input when you went to change the volume. look for a button labeled " input" or "video" select on the remote and scroll through the various choices. you should get your picture back.

It could be that the unit is bad, it could also be that the device providing the input is bad. I doubt the cables are bad, but that could be also. Could it be possible that your television has a menu setting that turns the outputs off and on?

Even without the sub, you still get sound through the Bar.

Only way to test it is, different cables, alternate device to provide input for sound.

you should have a button on your remote for sound system may be 'BG' or 'SYS' or any other press it to change sound system to "BG". sound will be ok.

There are some inductors that are out of spec. LG's original SB said to replace some of these with a jumper, but it only lasted a couple months.

You need to have the Total Main Assy replaced.

I bought my Insignia 32" LCD in November 2007 - same problem. I figured out that if you press the "input" button on your remote select any of the other options "component 1, composite 1, etc.. that you're TV isn't on -then press "input" again and go back to the component that you're TV plays on - you'll have volume when you go back every time. I've gotten so used to doing it now that it's become habit. 9 times out of 10 I have to do it.

its