On these sets- it's not that simply.
First the TV DOES need to be put on the TV Input setting- but there are more steps that need to be performed. You need to reset the TV to factory defaults, then when the initial setup comes on, you select "Antenna", then run a "Channel Scan". I will post these steps below:
To restore the TV to its factory default settings:
1. Press the MENU button on the remote. The on-screen menu is displayed.
2. Use the Arrow buttons on the remote to highlight the Help icon and press OK. The Help menu is displayed.
3. Highlight Clear Memory (Factory Default) and press OK.
4. Enter your parental control passcode. If you have not yet set up a parental passcode, enter the default, 0000. The TV displays, “Are you sure you would like to Restore Defaults? This will erase any custom settings.”
5. Highlight Yes and press OK.
6. Wait for the TV to turn off. The TV will turn back on shortly afterward and the Setup App will begin.