: Disconnect the power. Insert the microSD card. Use a toothpick to press the Reset button (hidden inside the AV port) while reconnecting the power.
[Insert download link]
If WiFi won't turn on after the update, your box likely has a different WiFi chip (like the RTL8723). You will need to find a firmware version specifically labeled with your WiFi chip's model number. mxq s805 firmware 51 download link
Hold the reset button (inside the AV port) and connect the box to your PC via the USB port (usually USB-4). The tool will detect the device and begin the flash. : Disconnect the power