Check if the TV is set to the correct source/input.

1. Check the batteries in the remote and make sure they are replaced.
2. Unplug the power from the TV and plug back in.
3. Run through the TV set up guide.
4. Check if any of the TV settings are enabled such as audio description or game mode.
5. Look for any firmware or software updates
6. Try different remote controllers and check if the TV responds.
7. Re-program the remote to the make and model of the Smart TV.
8. Check the manual for any other troubleshooting methods.