To turn on an Android phone without Power button, put the phone in fastbooot mode using Volume Up+Volume Down and connect the phone to a computer.

How to Restart an Android Phone Without Power Button There are many reasons why the power button of your device is not working.

How to Unlock Android Phone Pattern Lock without Factory Reset: If you’re using an Android device running version 4.4 or earlier, you can use the “Forgot Pattern” option to unlock your phone ...