Hello Bgiehl83,
We understand you're not seeing photos on your old Apple TV. You'll want to start with making sure iCloud is set up on your Apple TV, since you mentioned it was reset unexpectedly. Sign in to iCloud on all your devices will walk you through getting iCloud set up again.
"Set up iCloud on your Apple TV
- On your Apple TV, open the Settings app.
- Choose Users and Accounts, then select your account.
- If you haven’t signed in with your Apple ID for iCloud, choose iCloud > Sign In, then enter your Apple ID and password.
- In the iCloud section, choose an app or feature, then turn it on or off."
Which feature you'll want to enable will depend on what you're wanting to see within Photos on your Apple TV. Apple TV Photos app at a glance covers the different options you have, and what you'll need to do to set up each.
Let us know if this helps.
Regards.