Hello ericce,
To start, you'll want to add more specific detail to your post. What is not working on your Apple TV? Is the Apple TV completely dead/unresponsive for example? Are you having a problem with a specific application on it? Are you getting some sort of error code/message on it? Etc.
Details like these will help give the community a better idea of what you're talking about so members can provide more relevant responses.
If the Apple TV is completely unresponsive, you'll want to follow the steps from the resource you came to us from: If your Apple TV doesn't turn on or shows a black screen
"If you experience a black screen that is unrelated to switching the Apple TV format, try these steps. After each step, check if your issue has been resolved.
- Unplug both ends of the HDMI cable, then firmly plug them back in. Or try using a different HDMI cable to see if the cable causes the issue. For HDMI 2.1, use an Ultra High Speed HDMI cable. For HDMI 2.0, use a Premium High Speed cable. Then in the TV menu, make sure that you select the HDMI input that matches the HDMI port connected to the Apple TV.
- Unplug your TV and your Apple TV from power, then plug both back in.
- Try a different HDMI port on your TV, starting with HDMI 1 or Input 1. Check your TV manual for further assistance.
- If you're using a receiver or an HDMI switch, one of these might be the issue. Connect your Apple TV directly to the TV instead of using the receiver or HDMI switch. If the Apple TV Home Screen now appears, connect your receiver or HDMI switch one at a time. After each additional device is connected, check that the Home Screen still appears on your TV. Check your receiver manual for further assistance.
- If the Apple logo appears and then a black screen, press and hold the Back button and Volume Down button for 6 seconds, then release. Your Apple TV will switch to a new resolution every 20 seconds. Select OK to choose a resolution or Cancel to quit."
Cheers!