Help & troubleshooting for network issues, including connecting your device to your home Wi-Fi network, connecting to public networks, troubleshooting wireless issues & ethernet connections, and optimizing streaming performance.
Duct tape -- it can fix anything. 
Okay, with that out of the way ...
Roku only supplies the operating system for a "Roku TV". Hardware issues needs to be referred to the manufacturer of the set.
Roku TV Manufacturer Support Contacts:
https://community.roku.com/t5/Manufacturer-Support-Warranty-Resources/Contacting-Support-for-Your-Ro...
If you want to "do it yourself" a YouTube search for your TV model (or at least its manufacturer) may be your best bet for instruction. Try "replace [brand name] coaxial connector" or "replace [brand name] antenna connector".
