Before you give your handset to repair shop or buy new handset, please try the following procedure to repair your device. First charge your battery more then 70%, backup your important data like phone-book, message, email, images and settings and in most cases take out SIM card and SD card. After doing hard reset not possible to recover your data, so online backup is always important. For all of your data, a backup should be done on a external device, hard drive, raid system media or SD card.
How to Hard Reset LG D821 Nexus 5
Reset via Setting
- Make sure, that your phone is on.
- From the Home screen, tap Apps > Settings > Backup & reset
- Tap Factory data reset.
- Tap Reset phone > Erase everything to perform a factory reset. Your device will restart when the reset is complete.
- Make sure, that your phone is off.
- Press and hold the Volume Down + Volume Up + Power/Lock keys until the device turns on. You will see the word Start with an arrow drawn around it.
- Press Volume Down key twice to designate Recovery mode.
- Press Power/Lock key to restart into Recovery mode. You will see an image of an Android robot with a red exclamation mark.
- While holding down Power/Lock key, press Volume Up key.
- Use the volume keys to scroll to wipe data/factory reset and press Power/Lock key to select it
- Scroll down to Yes - delete all user data and press Power/Lock key to select it. Your device will reset to factory settings
Note: If at any point during the above steps your phone becomes unresponsive, you can restart it by holding down the power button for several seconds.