[LG Optimus L9 P760, P765, P768, P769] punjabi4life:
I have made this tutorial due to me not finding any other tutorials on fixing the problem presented in this guide. Dear admins if there is another guide on how to fix this problem please feel free to do what you must to this thread. Thank You

First of all is if you have the security error problem on your phone I can assure you that it is NOT bricked and can be fixed.

Also I am not and will not be accountable if this guide does not fix your phone. I also will not and should not be held accountable if this guide is to further damage anything of your phone.

PROCEED WITH CAUTION; Please Pre-Read this guide and understand it before proceeding.

Okay so I will guide you through on how to fix the security error problem most people have on their LG devices. I had encountered this problem on my friends LG MS769 (Optimus L9 – MetroPCS). This guide should work for mostly any LG phone.

This happened to me when I was flashing a custom recovery for the phone. I had successfully rooted the phone using a guide located at:

androidforums.com/optimus-l9-all-things-root/759935-how-root-metropcs-l9-lgms769.html

By following the above guide you will be able to successfully root and install SuperSU on you LG MS769. But keep in mind that even though it will root the phone is will NOT, I don’t know how to emphasis this as much, it will NOT: Unlock the BootLoader, Flash a custom recovery, or let you install a Custom Rom.

But let us come back the topic at hand. Okay so to fix this problem we will need the following.

LG Mobile Support Tool -- B2CAppSetup.exe -- Attached

A reliable Internet Connection

A computer with Windows XP/Vista/7/8 – (Untested on Windows 8)

TIME and PATIENCE --- We will be downloading a file about 500MB give or take some.

Okay let us begin in our endeavors of fixing our problems. :)

First use the below download link to download the LG Mobile Support Tool

After downloading that place it on your desktop and run it as administrator

After you run B2CAppSetup.exe it should automatically open the Mobile Support Tool, if not there should be a new .exe created on the desktop called LGMobile Support Tool just double click and open that.

Let the program update and install any necessary files that it requires. (It should automatically start to update and install, it should just prompt you with a UAC window)

Once you see the program open, click on the Install USB Driver button on the top left-hand side

Then a new window will come up asking for you for the phones carrier and the phones model number.

Once you are successfully done installing the drivers, we can proceed to the restoration process of the phone

Okay now we need to put the phone in S/W Upgrade Mode.

a.Remove phone battery, if it does not have a removable battery make sure phone is off

b.While holding down the VOLUME (DOWN or UP or BOTH) BUTTON(S) insert the microUsb in the phone while also having the USB side connected to the computer already. (To enter S/W mode it varies phone to phone which volume buttons must be pressed, try all three options)​

Once the phone is in S/W Upgrade Mode the computer will start to install the drivers and the LG Mobile Support Tool will automatically detect it and start the restore process

a.Keep in mind that this process takes its time and should more than likely complete successfully giving you a working phone

b.

NOTE:

I have read some people calming that the process gets stuck at 4% and does not go on. If it does happen to get stuck at any percentage let it stay there for a while and see if it does go on, if not I would recommend retrying once on the same computer and if it still does not work I would give a second recommendation to try on another computer. Other than that I would suggest you contact you phone carrier or LG. :(​

If all goes well you should have a fully functioning factory restored LG phone. Congratulations!!!!

Hope this guide was of help and I wish you best of luck in your further endeavors. :good: