Click the Download button in the tool. Power off the Sunmi V2 completely. Hold the Volume Down button (or sometimes no buttons depending on the hardware revision) and plug the USB cable from the PC into the device.
Simple factory resets through the menu often fail to remove management software like MobiControl, which can remotely relock the device. How to Update or Restore Your V2 Sunmi V2 Firmware
Choose Firmware Upgrade or Download Only from the dropdown list. Warning: Avoid using "Format All + Download" as it will wipe the device's unique IMEI number and printer calibration data permanently. Click the Download button in the tool
The Sunmi V2 firmware offers a compelling value proposition for businesses seeking a reliable, feature-rich POS solution: Simple factory resets through the menu often fail
If the printer stops working after a firmware update, go to and select "Printer Firmware Update" to ensure the printer component is synced with the main OS. 3. Stuck at Boot (Bootloop)
Ensure the battery is charged to at least 30% or connected to the power adapter.