New Samsung G900a Unlocked, Comes with 30 day warranty. The first step is to power cycle your device. Press and hold the Power/Lock button, the tap Power off. To turn the device back on, press and hold the Power/Lock button until the screen lights up. To restart your device, press and hold the Power/Lock button, then tap Restart. Tap Restart again to confirm. A Factory Data Reset reverts the device back to factory settings. It will permanently erase all personal data Tap the Settings icon. Swipe to the User and backup section, then tap Backup and reset. Tap Factory data reset. Tap RESET DEVICE. Tap DELETE ALL.