LG Optimus F3 hard resetUsing the Optimus LG F3 / LG LS720 hard reset
If you perform a factory reset, all user applications and user data will be deleted. Please remember to back up any important data before performing a factory reset.
When you can't recall your unlock Pattern, PIN or Password:
1. Turn the phone off.
2. Press and hold the following keys for 5 seconds: Volume Down Key + Power/Lock Key .
3. Release the keys when prompted
4. Press the Volume Down Key to scroll to wipe data/factory reset. Then press the Power/Lock Key to select it.
5. Press the Volume Down Key to scroll to Yes -- delete all user data. Then press the Power/Lock Key to select it.
6. The phone will perform a factory reset.
7. Make sure that reboot system now is highlighted and press the Power/Lock Key to make the selection and reboot your phone.
To reset your LG Optimus F3 Andorid Jelly bean or ICS to factory settings and erase all the data on your phone using the menu, select Settings → Back up and reset→ Factory data reset → Reset device→ Delete all.
1. On the Home screen, touch the Menu Key .
2. Touch System settings > Backup & reset > Factory data reset.
NOTE You can touch the checkbox to also erase all contents from your microSD card when the phone is reset.
3. Read the warning and touch Reset phone.
4.Touch Erase everything.
Attention: If a factory reset is performed, all installed application and user data will be erased. Please remember to back up any important data before performing a factory reset.
Resetting the phone does not erase any system software updates you have downloaded or any files on your microSD card, such as music or photos. If you reset the phone in this way, you are prompted to re-enter the same information that you did when you first started Android.
You can use LG Mobile Support tool to repair your LG cell phone, after download select menu Customer Support > Recovery Phone (LS720)
Go to Support > Mobile Phone Support > Select the Model LS720