New TV. After initial set up, the cartoon channel comes on and I can't change channels. Completed "FIND CHANNELS". Clicked OK, screen went back to "CHANNELS" . Made it to "CHANNEL SOURCE", selected cable. Went back to "CHANNEL SOUICE", while Cartoon Network remains of right hand 3/4 of screen. New TV is in bedroom, no cable box, cable connect from wall and I had previously identified the connection as such. Need help! Am old man. Patience may be required.