Apple TV and LG TV NO Signal

Confirm the HDMI port you plugged into (from your Apple TV) corresponds with the same input you select

Set up your Apple TV - Apple Support

Plug your Apple TV into power and connect it to your TV with an HDMI cable. To watch movies in 4K HDR on Apple TV 4K, make sure that you’re using an HDMI 2.0 or later cable, and have a TV that supports 4K, HDR, or both. Then turn on your TV and select the HDMI input that your Apple TV is connected to. 

Don't see the set up screen?

If you don't want to connect to Wi-Fi during setup, you can connect your Apple TV to your router with an Ethernet cable.

What is your model Apple TV? Identify your Apple TV model - Apple Support

• The TV may not select the HDMI input automatically, depending on settings. Can you select the input connected to the Apple TV box manually through the TV?
• The video settings may not match the other TV. You can cycle through video settings with the remote until a working settings is found. If you see (the Apple logo and then) a black screen - Apple Support