Are you trying to fix a or just looking for the latest features ?
: When a new version is released, the TV will often display an OTA (Over-the-Air) upgrade notification when connected to the internet.
Extract the firmware file (usually MstarUpgrade.bin or similar) from the .rar archive to the root of the USB drive. Power off the TV and insert the USB drive.
: On some models, go to Settings > Support > Software Updates . USB Firmware for Stuck TVs