Based on user reports for similar TCL firmware updates (such as V583), these updates are generally highly recommended over factory-installed versions like V509.
Insert the USB into the TV and follow the system update prompts in your TV's settings menu. Download NT67F02 LF1V614 part1 rar
Users report that newer firmware versions significantly improve overall UI responsiveness, often described as "night and day" differences. Based on user reports for similar TCL firmware
While the manual USB update process is effective, users note that TCL's lack of consistent Over-The-Air (OTA) updates for all regions can make the process tedious. How to Use the Downloaded File Download NT67F02 LF1V614 part1 rar
Ensure you have downloaded all parts of the firmware.
Updates have been known to resolve "poor" image quality issues that lead some users to consider returning their televisions.