With the device turned off, press and hold the volume down button (located at the right panel of the device), and then press the power button. When the device’s display turns on, release the volume down button.3.Use the volume buttons to select REBOOT NOW, and then press the power button.
This should get the device to boot up and being working again- if not you will need to go to a servcie center to have them look at phone.
Hope this helps
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