There are a variety of ways to test and fix a Fire Stick that’s not connecting to the Wi-Fi or not loading properly. Sometimes a Fire Stick takes a while to load or install updates. If you turn your Fire Stick on and it sits on the logo loading screen, wait at least 10 minutes to see if the issue resolves itself.
If Fire Stick doesn't respond, try to restart your Fire Stick. Press Select and Play on the remote for 10 seconds to quickly restart your Fire Stick. This can fix a variety of loading issues and the black screen bug.