The screen of ZTE N970 is locked, no matter how you press it.

Press the "Volume-"key in the power-off state, hold it down, and then press the power-on key. Release the power button after the screen lights up, release the "Volume button" after entering the HBO, press Volume+or Volume-to select "Restore" and press the "Power button". If you enter a red triangle interface, this interface is normal. At this time, press and hold the volume up button, and then press the power button to confirm that you can enter the recovery. Enter revocore mode (the volume up and down keys represent up and down selection, and the power-on key represents OK). Then choose to restart the system for the first time now.