Can someone tell me why I recently had to change my Tv from Channel 3 to Channel 4 with the use of my Converter Box to avoid certain commercials and bold black lettering from shaking on the picture? This is a 1986 RCA TV.

I had always used the Channel 3 setting before and had no problem until before Thanksgiving.

Could it be something with the Tuner on Channel 3 or just a glitch with the conversion on the box?

Thanks.

Fine tune adjustment. ;)

Sometimes it just needs to be re-adjusted or is bumped.

How and where would you make the adjustment on the inside of the cabinet?

Thanks.

If it is a rotary tuner, it may be dirty on the channel three contacts. Four is probably cleaner and therefore a better picture.

How and where would you make the adjustment on the inside of the cabinet?

Thanks.

Well for one, I wouldn't think it's done inside the TV, usually on the tuner outside.

What's the model? Without the model this is a guess.. On my TV there's an inner knob on the main knob, and when pushed in and rotated, it fine tunes.