In order to hard reset a LG A7150, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
LG A7150 device will be brought back to the default configuration of a brand new device.
1. For starters, press the Power button until the phone turns itself on.
2. Starting from the Home screen, open Main Menu, select Reset Settings and Master Reset.
3. Enter the securidy code -0000 by default - to confirm.
4. Your phone will now reboot and restart. Congrats.