Uninstall and reinstall the latest graphics driver for your graphics card first. Go to Device Manager then uninstall the graphics driver same goes in Programs and Features. Once removed, download and install the latest driver that can be found in this link: http/support.amd.com/en-us/download. Use the Auto Detect so it would give you the exact and latest driver there is. Reboot the laptop once driver has been installed and test it out using HDMI output. Press Windows key + p at the same time then select either Duplicate or Extended.
If the resolution of your laptop screen is too high for the TV you won't get any picture. If you set the TV as a 2nd screen, set the resolution of that screen for the native resolution of your TV if should work fine.
Sometimes the order that you turn things on and switch inputs matters too. If the laptop is on when you switch the TV to that input try it with the laptop off and then boot the laptop.