Copy the firmware file to the root directory of the USB drive (do not put it in a folder). Initiate Update: Power off the TV and unplug it. Insert the USB drive into the TV's USB port. Press and hold the physical Power Button on the TV (usually located underneath or on the back). While holding the button, plug the TV back in.
If your goal is to understand, analyze, or develop firmware for a device like (possibly a power management IC, touch controller, or wireless chip), here are paper types and specific search directions that would be useful: Tpd.rt2841.pb772 Firmware
Usually a .bin or .pkg file (e.g., allupgrade_v2841_...pkg ). Copy the firmware file to the root directory
rename random files to these extensions. Press and hold the physical Power Button on
TPD.RT2841.PB772 is a widely used mainboard (motherboard) specifically designed for TCL Android Smart LED TVs