Copy the extracted firmware file (usually named V8-xxxxxx.bin or MstarUpgrade.bin ) directly to the root directory of the USB—do not put it inside a folder. : Turn off the TV and unplug the power cord. Insert the USB drive into the TV's USB port. Press and hold the Power button on the TV (not the remote).
: If community links are broken, you can try contacting the TCL After-Sales Team with your specific serial number to see if they can provide a direct download link. Download TCL LED40D2939 Firmware part2 rar
Use a USB drive (ideally 8GB or smaller) formatted to . Copy the extracted firmware file (usually named V8-xxxxxx
: If you only have part2.rar , the extraction will fail. You must locate part1.rar from the same source to successfully rebuild the firmware file. Press and hold the Power button on the TV (not the remote)
Wait for the progress bar to reach 100%. The TV will usually restart automatically.
While holding the button, plug the TV back in. Keep holding until the "Software Upgrading" screen appears.