Use a 4GB or 8GB USB drive formatted to FAT32 .

A frequent source for Universal Android Mainboard software . USB Installation Guide (Step-by-Step)

Flashing this board is straightforward if you follow the standard USB method. Always backup your original data if possible, as incorrect firmware can result in a "flipped" or solarized image.

Plug the USB into the TV's USB 2.0 port while the power is off.

Capable of driving 4K*2K panels, but often configured for 1920x1080.

If the TV is stuck on a red light, you may need a full eMMC dump and a programmer like the RT809H, as the USB method might not work if the bootloader is corrupted.