What should I do if my device is stuck during upgrade process?

It needs to take some time for system upgrade. Please wait for 3 to 5 minutes to check whether upgrade process will be automatically finished. If long time no response on the device, forcibly shut down the device by long-pressing Power button or removing battery pack. After that, try to power on the device. If it can be powered on normally, please back up data first, then format SD card, and repeat the steps to system upgrade. If fail to upgrade system, please contact our technology personnel.