Format the card or drive on your PC using the FAT32 file system. A quick format is usually fine, but a full format ensures there are no corrupted blocks. Locate the files:
Unlike standard MCUs that simply flash a .bin file via JTAG or UART, the RKPX3 update process typically follows the Rockchip standard: rkpx3 mcu update
If your screen is black or stuck in a bootloop, use the physical recovery method. Insert the SD card containing the file. Format the card or drive on your PC