How to forcibly restart vertu constellation 4?

1. Press and hold the power button and volume up button on the right side of the phone (at the same time) until the screen is closed, indicating that the phone is turned off.

2. Then press and hold the power button and volume increase button again until the Vertu logo appears on the screen.

3. Release all buttons and wait for a few seconds until the phone restarts and enters the system interface.