LG Optimus F3Q hard reset

Using the Optimus LG F3Q / LG D520 hard reset

If your phone needs to be restored to its original condition, use a Hard Reset to initialize your phone.
Warning! If you perform a Hard Reset, all user applications and user data will be deleted. Please remember to back up any important data before performing a Hard Reset.
1 Turn the phone off.
2 Press and hold the Power/Lock Key + Volume Down Key at the same time.
3 Release the keys when the FACTORY HARD RESET screen appears.
4 Press the Power/Lock Key to continue or press any other key to cancel.
5 Press the Power/Lock Key again to confirm. Your phone will be restored to its factory settings. To cancel, press any other key.
lg optimus f3 d520 hard reset

You can use LG Mobile Support tool to repair your LG cell phone, after download select menu Customer Support > Recovery Phone (D520)

Go to Support > Mobile Phone Support > Select the Model D520

Using LG Optimus F3Q Safe Mode

To recover your phone when malfunctioning.
1 Turn off your phone and reboot. When you see the T-Mobile animation
press and hold the Volume Down Key until the phone reboots. Your main
screen will then be displayed with the words “Safe mode” in the lower left
2 From the Home screen, tap the Menu Key and tap System settings >
3 Tap one of the available tabs at the top of the screen and select the application
you wish to uninstall.
4 Tap Uninstall and OK to confirm.
5 After uninstalling the application, reboot your phone.

General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.