Once you have the .rar file, follow these steps to update the board:
Insert the USB drive into the TV's USB port while the power is off. Download RD8503 General 1920x1080 USB rar
This community forum provides a post titled "T.RD8503.A8 USB Firmware Software Bios Bin" which explicitly lists the 1920x1080_USB version. Once you have the
). Firmware for this board is typically distributed in .rar or .zip archives containing a .bin file used for USB flashing. Once you have the .rar file
Extract the .bin firmware file (often named SKR8503_100.bin or similar) from the archive.
The specific file you are looking for, , is frequently hosted on electronics repair forums and community technical sites: