In order to hard reset a Hisense L671, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Hisense L671 device will be brought back to the default configuration of a brand new device.
2. Press & hold the Volume Up and Power buttons. Release them after the Hisense /Android logo/Recovery Mode/Boot Mode appears on-screen.