Should you have both an HDMI and Ethernet cable plugged in to your AppleTV?

I think you may be a bit confused, a HDMI cable and an Ethernet cable do totally different things. Please let me explain:

• HDMI is needed to connect to your TV or HT Receiver in order to transmit the video and sound signals to your TV.
• Ethernet is used to connect your device to the Internet. Your Apple TV can connect to the Internet either via Wi-Fi or by Ethernet. If you have a Ethernet cable connected to your router and Apple TV the Apple TV will default to using the Ethernet connection.

If you need help setting up your device please follow the directions in https://support.apple.com/en-us/HT205358 and if you need to talk to someone for help, give AppleCare a call. You can find the phone number for your part of the planet by clicking AppleCare contact Information

Your welcome and bless your heart for making it to 83 and trying to do things on your own! I'm also very sorry to hear of your recent loss.

To fix your "no signal" problem please do the following:

• The Apple TV must have an indicator light illuminated. this means the Apple TV is on and ready.
• The TV needs to have the correct input selected, please look on the TV's remote for an "input" button. You want to match the input that you used to connect the HDMI cable to. For example if your Apple TV's HDMI cable is in input #1 on the TV then you want to select Input 1 on the TV remote.

Well done and I'm glad you got it working again.

Double-check that your HDMI cable did not 'Pull' out of your Apple TV or your TV, that has happened to me before when I get "no signal"