Perform a soft, factory, and alternate master reset of the device.
INSTRUCTIONS & INFO
There are multiple ways to reset your device if you are experiencing issues. The first step is to power cycle your device. Press and hold the Power button, then tap Power off. To turn the device back on, press and hold the Power button until the screen lights up. Note: If you are unable to turn your device off, remove and re-insert the battery.
If a power cycle does not resolve your issue, perform a device restart. Press and hold the Power button, then tap Restart. Note: If you are unable to access the screen to ‘Restart’ the device or if it becomes unresponsive, press and hold the Volume-down and Power buttons simultaneously for 10 seconds, until the device restarts.
If a restart does not resolve your issue, you may need to perform a Factory data reset (Master reset). This will erase all data on your device and restore it to factory settings. To ‘Factory data reset’ your device, swipe down from the top of the screen, then tap the Settings icon > Backup & reset > Reset phone > OK Note:A Factory data reset will revert the device back to factory settings. It will permanently erase all personal data, preferences, settings and content such as pictures, ringtones and apps that are saved to the device. It is recommended that you save (backup) important data before proceeding.
If unable to perform the standard ‘Factory data reset’ using the above steps, try the Alternate method by first powering the device off. Note: With your device powered off, press and hold down the Volume-down and Power/Lock buttons simultaneously until the phone vibrates, then release Power key. Release the Volume-Down key when the black screen with red and blue lines of text appears. Press the Volume-Down key until reboot to bootloader is highlighted, then select it with the Power key. Press the Volume-Down key until REBOOT TO RECOVERY MODE is highlighted, then select it with the Power button. After several seconds, a picture of the phone with a red triangle and exclamation mark will appear. Hold the Power key, while pressing and releasing the Volume-Up key. Press the Volume-Down key until wipe data/factory reset is highlighted, then select it with the Power key. Press the Volume-Down key until Yes – delete all user data is highlighted, then select it with the Power key. Once the data wipe is complete, select reboot system now press the Power key.