To update the XHDATA D-808, you need specific hardware. You cannot use a standard printer USB cable.
Disclaimer: This report is for informational purposes only. Modifying device firmware carries inherent risks. I am not responsible for any damage to devices resulting from attempted updates. xhdata d-808 firmware update
XHDATA D-808 does not support user-accessible firmware updates To update the XHDATA D-808, you need specific hardware