Since the file is a .rar archive, you must first extract the actual firmware bin file from it on a computer.
: Ensure your USB drive is formatted to FAT32 . Download Tcl L32D3000A RD853V AP@asad rar
: Plug the USB drive into the USB port on the back or side of the TV. Since the file is a
: Keep holding the button until you see the front LED light begin to blink or an "Upgrading" progress bar appears on the screen. : Keep holding the button until you see
Select to check for the latest official version available over the air.
: Use a utility like WinRAR or 7-Zip to extract the contents. You are looking for a file that typically ends in .bin or is named Update.img .
If your TV is functional and you simply want the latest official software, you can often update directly through the menu: