Have a new Comcast cable connection with modem Arris TG862G/CT. Have connected multiple laptops in the house over wi-fi network after providing Network name (SSID) and Network Key (both provided on the bottom of modem Arris TG862G/CT).
However, am unable to connect a Vizio TV (model M420KD) to this new wi-fi network. After selecting the network and providing WPA passphrase (same as Network key?), it displays the message "Unable to connect. (Note: TV was earlier on the wi-fi network for a DSL connection from verizon.)
1. Reset the TV's nework setting completely to remove any settings from the previous wireless connection that may cause trouble. That means proxy settings, wireless settings, TCP/IP settings, etc. Everything.
2. Log into the gateway and change the wireless security settings to WPA2PSK with AES, DO NOT USE the combo WPA/WPA2 setting, many devices get confused and won't work properly.
3. Try connecting the TV again. If the automatic scan and connect doesn't work or it doesn't ask for WPA2 passphrase (if it asks for WPA, something is wrong), try a manual configuration where your explicitly enter the SSID and WPA2 passphrase.
4. Try changing the wireless channel on the gateway, your TV many have trouble with the current selected channel.
5. If that fails, try connecting with an ethernet cable.
I have the exact same modem (Arris TG862G/CT) and am trying to get a wireless connection to a Vizio TV (M3D460SR). I walked through the steps you outlined and was able to get the TV to show a connection, however, when I run a wireless test on the TV I show excellent signal strength but zero data coming into the TV and no internet apps work.
I was also experiencing the exact same issue connecting my new Vizio TV to my wireless network. I was using WPA/WPA2. I changed my wireless network configuration to use WPA2 Personal (AirPort Extreme only uses AES) and that did the trick. I'm now connected using wifi and currently watching a movie using the amazon app. Thanks for posting the resolution!
i've restored the settings, checked my gateway and it's been at wspa2-psk AES the entire time and though it picks up the network name, the password that's worked for all my other devices, isn't connecting to the tv. what else do i do?