[LG G5 ROMs, Kernels, Recoveries, & Other Developme] wemi:
My H850 LGUP story

Hi,

as yesterday I "bricked" my LG H850 and only had access to the USB download mode when trying to get LGUP working, I would like to share what I did to brick and what to recover.

My setup / starting point:

- LG G5 H850

- Stock ROM 20d installed using Codefire zipfile and TWRP 3.1.1

- I wanted to get rid of the error 0x1125000 upon OTA update attempts, so I wanted to install the kdz with LGUP

- PC OS: Linux, Windows 7 N in a VirtualBox5 VM

To brick, I did the following:

1.) Install LG Driver 4.2.0 + LGUP 1.14 Store + UPPERCUT

By the way: In the first place, the COM port appeared only when the Android was booted, but not while in USB download mode. In this mode, the device manager showed a disfunctional "composite device" (German: USB-Verbundgerät) with error code 10. Then I figured out that in the configuration of VirtualBox, I had only chosen USB 1.1; enabling USB 2.0 solved the issue.

2.) Load 20d kdz file -- LGUP hangs at 4%. [IMG="LGUP1.14 Store with Uppercut, flashing stuck at 4%"]https://imgur.com/kbDA0q4[/IMG]

Meanwhile, the phone showed

* first: "633A B50" in the box with the grey rectangle around it, grey progress bar at 0%

* second: in the same box: "U 633A S0.0 AS0.0 B88 UHS / S U LG H-850 O7.0 Hrev_11 / H85020d / LGH850AT-00-V20d-OPT1-HQ-APR-03-2017+0" PLUS a big green "COM4" above the progress bar, which was still at 0%

* third: (after about half a minute) same as first

3.) I disabled Windows Defender (German: Extras > Optionen > Echtzeitschutz > untick "Echtzeitschutz aktivieren (empfohlen)" / English, translated freely: Extras > Options > Real time protection > untick "Enable real time protection (recommended)") -- did not help.

4.) I then stumbled upon the quote below suggesting that wiping the misc partition (option 1) is not too dangerous -- this did not help; worse, the phone would neither boot into Android nor into fastboot, but a message in partially purple letters showed up suggesting that the firmware integrity check failed and the device was not able to boot. This message appeared pretty quickly, as far as I recall, it was one or two seconds after pusing the power button. This is the state that I call "bricked".

To get the phone to work again, I eventually managed to

1.) uninstall LGUP 1.14 Store

2.) install LGUP 1.11 Lab and LGH850_DLL-V2.msi

Note that had I tried the other H850 DLL (without V2 in its name) as well, but this led to a crash of LGUP.

3.) This way, flashing the 20d image using the upgrade option was successful. :)

I noticed the following peculiarities afterwards:

- Immediately after flashing, I was presented a bootup password prompt for which I did not know the password. I made a factory reset using the stock recovery and the prompt disappeared.

- The bootloader is locked again, without doing anything else than what I described.

- Now, at each bootup I get the message "WARNING! Current version is not available for user. Can't find matched cust for NTCODE = [,]" (Note that other forum entries concerning this contain MCC and MNC in the square parenthesis -- mine are empty like written.) I would guess that some data on the misc partition that I had wiped was wrong? This is the only actual question in this post -- if anyone knows of a simple way to get rid of this, I'd e curious. Maybe by doing a binary comparison of the misc partition.... but that is nothing so important.

OTA updates also work again. :)

So eventually, great thanks to all the forum contributors that provided the tools and all tutorials (especially Team Codefire), and all the people sharing their experience.