On my Lenovo K6 Power phone, on the Android starting screen, the touch keypad for entering the pin is not working. The bottom row of buttons (comprising of the 'back' button, the '0' button and 'ok' button) does not function. When these buttons are pressed the screen displays characters of a row above, as if those have been pressed. So, I have not been able to start my phone at all. Can someone help with a solution?