Turn on the TV
Press and hold the Setup button on the Comcast remote until the LED changes from red to green
Press the TV button
Enter the TV brand code if you have it
Point the remote at the TV and press Power
If the TV turns off, press OK or Enter to save the code
If the TV does not turn off, repeat with the next code for your TV brand
If you do not have a code, press and hold Setup until the light turns green
Press the TV button
Press Power, then Channel Up repeatedly until the TV turns off
Press OK or Enter to save the code
Test the volume and power buttons
If needed, repeat the process with a different code or use the Comcast remote setup menu on your cable box