[LG Optimus L9 P760, P765, P768, P769] Rosso Corsa:
First of all, I apologize for having uploaded all the figures of my post in the "figure.zip" attachment, but I was not able to insert them as separate figures using the "insert image" function. I am a new user and perhaps I am not allowed to use this function.

I am not able to recover from a "soft brick" due to an aborted flash of a stock ROM. Here is the story.

I started working with this LG phone:

Model: L9 P760 (Vodafone brand)

OS Android 4.1.2 Jelly Bean (it was previously updated form ICS through the official upgrade from LG)

SW Version: P760 20d-262-02

Kernel: 3.0.31

Build: JZ054K

Baseband: L626_MODEM_SIC_01.1230.00

My goal was to re flash with another JB stock ROM, so upgrading its release and getting an unbranded phone.

I downloaded this stock ROM kdz file: V20H_00.kdz

Then I tried to flash with a procedure derived from this one: http://xdaforums.com/showthread.php?t=2085344

The main difference was related to the fact that I did not put the smartphone in S/W Upgrade status at the beginning, I connected it to USB port when it was power on and set the PhoneMode to "DIAG" instead of "EMERGENCY". The phone went in "S/W Upgrade" mode during the flash procedure.

I worked on my laptop, the operating system is Windows 7 Professional, SP1 64 bit.

A problem occurred during the update: the LG Mobile Support Tool crashed and the phone remained in "S/W upgrade" status. I restarted the LG Mobile Support Tool, but I was not able to make it continue the update. Then I disconnected the phone from USB and removed the battery. When I re inserted the battery the phone did not boot anymore.

Now my LG L9 P760 does not start pushing the normal power on button.

It does not make a factory reset if I push Power on, home and vol- buttons

There are no any combination of buttons I can start for having any reaction from my LG L9.

Then, I tried to recover from this "soft brick" status in the way I describe hereunder.

1) I removed everything related to LG from my laptop (LG Mobile tool -including LGMOBILEAX directory under C:\ProgramData- and LG drivers)

2) I installed the following LG SW:

LG drivers, rel. 3.11.3, from a file named: LGUnitedMobileDriver_S50MAN311AP22_ML_WHQL_Ver_3.11.3.exe

LG Mobile Support Tool rel. 1.7.3.0, installed through this program: B2CAppSetup.exe, running in Windows XP SP3 compatibility mode. From file properties , tab "details" I read this B2CAppSetup.exe is ver. 1.0.1.7.

3) I connected the smartphone to my laptop through the USB cable. After about 10 - 15 seconds it went in SW upgrade mode. At least, I see "S/W Upgrade - Please Wait while upgrading...." on the LG L9 screen. BTW, that occurs every time I connect the smartphone to my PC, in any cases: removing the battery or not removing it, pressing or not the vol+ button... In any cases it goes in that state.

Before connecting the smartphone, this is what Device manager showed:

[pls see devManager-phoneNotConnected.PNG in figure.zip]

After I connected the smartphone through USB, this is what Device Manager displayed:

[pls see devManager-phoneConnected.PNG in figure.zip]

Without starting the LG Mobile Support Tool I saw that after some minutes its display did not show the "S/W upgrade" message anymore, nothing was displayed. And after about 10 seconds the "S/W Upgrade.." message came back again. It is like the smartphone tried to connect to some applications running on the laptop, but did not find any process there, then it retried, and so on.

When the LG display was black, the Device manager output was like it was before connecting the smartphone to USB port. When "S/W Upgrade..." came back on the LG display, LG devices came back on Device Manager output.

4) At this point, when "S/W Upgrade.." was displayed on LG I started the LG Mobile Support Tool. It seemed it was able to recognize my smartphone, as I saw this output.

[pls see LG_MobileSupportTool-start.PNG in figure.zip]

But waiting for 1 or few minutes without doing anything the "S/W upgrade..." message disappeared on my LG display and LG Mobile Support Tool showed this output:

[pls see LG_MobileSupportTool-start01.PNG in figure.zip]

It was like the connection between the smartphone and the LG Mobile Support Tool could not be kept, or was not stable.

5) Anyway, when the connection seemed to be ok I selected the choice "Upgrade Recovery" under "Options" menu choice, and the recovery procedure started. This is the sequence output I saw on the LG Mobile Support Display:

[pls see LG_MobileSupportTool-start02.PNG in figure.zip]

[pls see LG_MobileSupportTool-start03.PNG in figure.zip]

[pls see LG_MobileSupportTool-start04.PNG in figure.zip]

But during the "Upgrading your phone..." phase, the process was always blocked at 15% of its execution (it remained at 15% for a relatively long time, let's say 2 or 3 minutes) and I read this output:

[pls see LG_MobileSupportTool-start05.PNG in figure.zip]

Now, if I retry the procedure (with or without disconnecting the phone, removing the battery and so on and the reconnecting) I get this message if I push the "retry" button when the LG display is black.

[pls see LG_MobileSupportTool-start06.PNG in figure.zip]

Otherwise, If LG display indicates "S/W Upgrade..." the procedure restarts, but always with the same result: it aborts at 15% of progress, and LG Mobile Support Tool shows the same error:

I tried a lot of alternatives avoiding to download the ROM image online from LG site. I tried the procedures I found here http://xdaforums.com/showthread.php?t=2085344 and also here http://xdaforums.com/showthread.php?t=2797190, where I found an interesting and more recent tool for an off line KDZ flash.

I tried to flash a couple of diferent KDZs: v20c_00.kdz -ICS- and V20H_00.kdz (JB) but always the procedure was aborted during the update.

I believe my problem should be related to 3 main factors:

Some issues on LG drivers, also if somehow my phone is detected by LG Mobile Support Tool, when I connect it via USB cable.

Some issues with the LG tools I use (or perhaps I do not configure everything needed in the right way, or perhaps there are issues with Windows 7 64 bit)

Some issues with the kdz I use. Perhaps I could adopt some othe stock ROMs (also if I have already tried with 2 different KDZ).

I tried these procedure using other PCs, another Win 7 64 bit and an XP SP3 32 bit, but basically the problem is always the same: the recovery / flash procedure is aborted at 15% of its progress.

Who could give me any advices on what could be the reason of this fault, and on what procedure I could do?

I have not tried anything related to adb or fastboot till now, as in my opinion my issue should not require these tools in order to be solved. I mean, my LG L9 easily goes in "S/W Upgrade.." mode, so it does not seem the problem is related to a boot loop status. Anyway, could a flash via fastboot solve my issue?

Pls help me, I can give you every additional details it could be useful...

Thank you in advance!

Ciao

Mauro