System upgrade as follows
① in the USB device, copy the upgrade file from the computer, after the file is decompressed, put the ISPBOOOT.BIN and OSU_Settings folder or update file in the root directory of the USB drive.
② Insert the USB, return to the main interface → Settings → Version Information → About the device → Update → click the corresponding file upgrade → upgrade in progress (during the upgrade process, you can not pull out the USB, the upgrade will automatically read the USB after completion)
The upgrade process can not be disconnected, pay attention to whether the U disk file name is correct, and determine the version information before upgrading