Factory reset will erase all data from your device's internal storage.
You have a problem with your device or you want to reset your device, you may use factory reset.
PM550, PM560
Navigate to
Tap
Please be aware that factory reset will erase all data. Tap RESET PHONE / Erase all data to start the factory reset.
Tap ERASE EVERYTHING / Erase all data to confirm the factory reset.
Press and hold the following buttons simultaneously when turning on the device.
After short vibration, release the buttons. Now your device is entered Android Recovery mode
Select 'Wipe data/factory reset'
After wiping the data, select 'Reboot system now'