Fire TV Black screen is the one most common issues while operating with a device. Most of the reason/cause behind this problem like slow internet, loose cable connection, Hardware Impairment with HDMI port and more. In my case, the issue with the internet connection. So, to resolve internet issue, I followed some steps that I found on [https://firesupportonline.com/troubleshoot/fire-tv-stick-black-screen/|here] and you can also try these steps:
Step 1: Try using different HDMI cable.
Step 2: Connect the HDMI cable to a different HDMI input port.
Step 3: Restart your router.