Restoring your device to default settings helps when the device crashes and resets itself or when apps freeze/hang or reset the device.
Performing these steps resets all system settings (e.g., ringtones, sound settings, display settings, etc.) back to their default values. Personal data such as downloaded apps and media (pictures, videos, music) are not affected.
From a Home screen, navigate: Apps icon > Settings > Backup & reset.
Tap System settings reset.
Tap Reset system settings.
If presented, enter login credentials (e.g., PIN, Password, etc.).