In order to hard reset a LG Quantum, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
LG Quantum device will be brought back to the default configuration of a brand new device.
1. Power button must be held down in order to switch off the device.
2. After the phone turns off, press the middle of the Volume button and the Camera button simultaneously.
3. Afterwards, as you hold the above buttons, press the Power button.
4. Release the Power button when the Cold Boot phrase appears on screen.
5. Continue to hold down the middle of the Volume and Camera buttons until the Welcome screen pops up.