Do you have the printed on the circuit board to ensure this is the exact match?
: Extract the .bin file from the .rar archive and place it in the root directory of the USB (not in a folder). Download RR8501 C031A V50 1920x1080 USB rar
: Look for sites like Kazmi Elecom , Labone Inside , or Azeem Tech . These communities often host archives of universal TV board software. Do you have the printed on the circuit