Turn off the cable box and turn it on after a few minutes. Alternatively, unplug the cable box from the power outlet and plug it back in after a few moments.
Maybe the antenna isn't plugged in the cable TV box's input port (usually labeled as RF IN), which would explain why you can't find TV channels.
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.