If there is no wifi network detected on the TV, please follow the below methods to do the troubleshooting:
1. Check whether the wifi SSID could display on your mobile phone.
2. Change another wifi channel for your wifi network. Then please check if the wifi SSID could be detected or not.
3. Make sure the SSID does not hide on the wifi router.
4. Check the Time and Date on the TV.
5. Try to restore the TV back to the factory default settings.
6. Please also check if the software of the TV is the latest one or not. If the software is not the latest one, please try to upgrade the software.
If the issue cannot be resolved, please feel free to call the TCL hotline for further help.