1. Check your Wi-Fi network name and password are correct by double-checking them against the router or modem.
2. Check your Wi-Fi connection is working on other devices.
3. Check router's setting are up to date.
4. Check Wi-Fi settings are up to date.
5. Check your TV isn't too far away from the router.
6. Reset your TV network settings.
7. Reset your router and modem.