Sites like firmware-file.com , driverscollection.com , or free-firmware.net often index files. Many bundle adware or outdated versions.
When the user connects via a terminal emulator (PuTTY, TeraTerm): tpdrt2841pb772 firmware free
To help you find the file version you need, could you tell me: What is the Brand and Model of your TV? (e.g., TCL 40S60A) Sites like firmware-file