Flashing the wrong firmware can "brick" your TV's mainboard. Ensure your board number ( MS638 ) and panel model match exactly before attempting to install. Do you have the other parts of this archive already, or
: There are several "TV Repair" or "Firmware" channels where technicians share these split archives. Download MS638 PC822 3840x2160 REF55 part4 rar
Since direct links to firmware parts are frequently taken down, I recommend checking these reputable technician hubs: : Search for the "MS638 PC822" chassis. Flashing the wrong firmware can "brick" your TV's mainboard
: A common repository for Skyworth/Coocaa 4K firmware. Download MS638 PC822 3840x2160 REF55 part4 rar