Plug the USB into the head unit's 4-pin or 6-pin USB port. Trigger the Update:
Finding a reliable AC8257 firmware update can be a challenge because these units are often unbranded or sold under various names like Junsun, Xtrons, or Hizpo. The AC8257 is a common chipset used in Android head units, specifically those featuring octa-core processors and built-in 4G LTE. ac8257 firmware new
Place the firmware files (usually a collection of files or one large .zip ) into the root directory of the USB. Do not put them in a folder. Plug the USB into the head unit's 4-pin or 6-pin USB port