Hint:Try the "Manual Tuning" option instead of "Automatic".
Otherwise,
1. Get the model # off the TV set (label on back).
2. Go to
http://www.lg.com/us/support/software-manuals
3. Enter your model # to access the owner's manual for your TV set.
4. Follow the specific directions for your set to switch the tuner from "Cable" to "Antenna".
5. Re-run the channel scan.
If needed, contact LG's customer support for additional assistance.
https://www.lg.com/us/support/message-customer-support