Typically, official TCL firmware for the L40S6500 follows a naming convention like V8-T851T02-LF1V635 . The higher the number after V , the newer the firmware (e.g., V635 is older than V701 ).
The TCL L40S6500 uses a proprietary firmware system, which is specific to TCL devices. The firmware version may vary depending on the region and country where the TV was purchased.
Typically, you place the update file on a FAT32-formatted USB drive, plug it into the TV while it is off, and hold the power button to trigger the update mode. Quick Tips for Troubleshooting
Release the button once the "Software Upgrading" screen appears. Do not turn off the TV during this process. Troubleshooting & Support Check Version : Verify your current version under Settings > Device Preferences > About > Product Information Factory Reset
