When you switch to cable, you have to select "setup" or an equivalent on the TV remote. On our Toshiba, we then select input or something like that where you have to select "cable". then you have to select program channels. You have to do this each time you change campgrounds, On our Magnavox in the bedroom, we just select program channels on the setup menu. It gives you the choice of cable or antenna and then programs the channels. Just be sure yuor antenna booster is off (green light is out).
Marty & Suzanne