At one time I had a very similar model and the Radio card went on the fritz and repairs were not a sensible solution. I bought a LG 65OLED and never looked back.
You have a couple cheaper options:
- Purchase a HDMI switch / Splitter . Use your Fire stick
or a better option 1 +
2. Buy a Roku 4K
End of life support for WebOS 1.4 is rapidly approaching if not already here.
Please note all updates to WebOS is for WebOS 2+