LG Optimus L9 P760 hard resetUsing the Optimus LG L9 P769 hard reset
1 Turn the phone off.
2 Press and hold the following keys at the same time for 8 seconds: Volume Down Key + Home Key + Power/Lock Key .
3 Your device will perform a factory reset and reboot. All data will be lost! Be sure to back up your data before doing a hard reset, factory reset.
Caution: If you perform a hard reset, all user applications and user data will be deleted. This cannot be reversed.
Remember to back up any important data before performing a hard reset.
To reset your LG Optimus L9 P760 Android hard reset phone to factory settings and erase all the data on your phone, Select Settings → Back up and reset→ Factory data reset → Reset device→ Delete all.
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
Go to Support > Mobile Phone Support > Select the Model (LG-P769).
LG L9 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 . Your main screen will then be displayed with
the words "Safe mode" in the lower left corner.
2 From the Home screen, tap the Menu Key and tap App 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, turn off and reboot your phone.