Format a USB drive to FAT32 . Copy only the extracted firmware file to the root directory of the drive. Flash: Power off the TV and insert the USB drive.
.rar (Part 3 of a larger archive). You must download all parts (part01, part02, etc.) to successfully extract the final firmware file. Where to Download Download MS638 PC822 3840x2160 Mitashi Ref35 part03 rar
Do not power off the TV during this process, as it can permanently damage the motherboard. Format a USB drive to FAT32