Try single mode G or N or mixed G and N? Setup/Wireless/Manual
Need to find out what wireless modes and security is supported by the TV. If your LT is seeing the router and the TV isn't, might be faulty wireless module on TV.
Channel Width set for Auto 20/40Mhz or try 20Mhz only. Setup/Wireless/Manual
What security mode are you using? Preferred security is WPA-Personal. WPA2/AES Only. Some WiFi adapters don't support AES, so you might want to try TPIK only or Auto. Setup/Wireless/Manual
Also can turn of security temporarily to test to see if TV can connect.