Matt wrote:
Hi Folks,

My TV works fine except that it won't stay on the channel it's set to.
It keeps cycling through the channels as if the channel-up button is
being pressed. The problem is not in the remote, since it happens when
the batteries are removed from the remote and the remote is put in a
different room.

The model is Panasonic CT-20G21, a 21" box from 1996.

I have little test equipment beyond a multimeter. I am able to solder,
and I have some understanding of electronics, but no experience working
on TVs.

Please advise.

Just a wild guess: Check the channel-up and channel-down buttons on your
TV. They should "click" when pressed. If the button is stuck down, or
the switch below the button is damaged, you probably won't feel that
"click", or it might have a "mushy" feel.