Turn on the power. The indicator light (often on the 7-key button panel) should begin flashing rapidly, indicating the update is in progress.
Insert the USB drive into the TV's USB port while the power is off. Download RD8503 General 1920x1080 USB rar
Extract the .bin firmware file (often named SKR8503_100.bin or similar) from the archive. Turn on the power
Similar software can be found on sites like Softwarezone.ga or dedicated Facebook groups like China LED-LCD Tv Bios Bin . USB Installation Procedure Download RD8503 General 1920x1080 USB rar