Apple sent a message with a black screen and no other response.

1. Connect the device to the PC;

2. Turn off the equipment;

3. Press and hold the home button and the power button for ten seconds at the same time (the time should be accurate).

4. Release the power button and continue to press and hold the home button until you see the usb device in dfu state on the computer and enter dfu mode;

5. After a few seconds, itunes can detect and identify devices in dfu mode (black screen state).

Exit dfu mode: press and hold the home key and the power key 10 second, and restart the device after shutdown.