In order to hard reset a BenQ S80, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
BenQ S80 device will be brought back to the default configuration of a brand new device.
1. Turn the phone on.
2. Open the Dialer.
3. Use the keyboard to type in this code, *#9999#. Confirm your action by pressing Call button.
4. Allow the device to restart. Voila, the hard reset is complete.