It often helps to start troubleshooting internet connection issues with these troubleshooting steps:

1. Check if the TV is connected to a working power source.
2. Check if the TV is connected to a power surge protector.
3. Check if the modem is connected to an active internet provider.
4. Check that the modem is powered on.
5. Unplug the modem to power cycle it.
6. Check if the Smart TV is connected to the modem via a wired or wireless network.
7. Check for any network settings that may have been changed on the Smart TV.
8. Check if the firmware of the Smart TV has been updated recently.
9. Restore network and/or reset factory settings on the Smart TV.