If you're experiencing a black screen on your Amazon Fire TV Stick, it could be due to a couple of different reasons. One possibility is that there's an issue with the HDMI connection between your TV and the Fire TV Stick. Another possibility is that your Fire TV Stick's power adapter may not be plugged in correctly, or it may be loose.
If you're sure that the HDMI connection is secure and the power adapter is plugged in correctly, then it's possible that there's a problem with the Fire TV Stick itself. In this case, you may need to contact Amazon customer support for further assistance.