Why won't my LG smart TV work on the guest network?

The short answer

Casting from a phone stops working across a guest network. Guest networks deliberately stop devices from seeing each other. That is exactly what this gadget needs to do, so it fails — as designed.

What's happening underneath

Casting and phone remotes stop working.

Source: Manufacturer documentation

Try these, in this order

• • Run a network cable to the TV if the router is in the same room — it beats any Wi-Fi fix.
• • Turn off the TV's 'quick start' power saving, which can drop the Wi-Fi overnight.
• • Move the router so it isn't directly behind the TV or a metal bracket.
• • Check the signal where the gadget actually lives, not where you're standing.
• • Move the router off the floor and out of any cupboard before buying anything.
• • Put the gadget and your phone on the same Wi-Fi name.
• • Restart the gadget before the router — it is quicker and it fixes more.

Setting it up again properly

• • Stand next to your router while you set it up, then move the gadget to where it lives.
• • Put your phone on the 2.4 GHz network name for the setup, or use one name for both bands so the phone can follow.
• • If your router splits bands into two names, turn the 5 GHz one off for five minutes rather than fighting it.
• • Turn mobile data off on your phone during setup — some apps quietly use it and never find the gadget.

When it's worth spending money

A £5 network cable or powerline adapter before any new Wi-Fi kit.