[G4 General] learhackna:
Unbricking LG G4 H818P during Nougat downgrade/LGUP error 0x2000/LG Flash Tool 2014 unable to connect to server/LG G4 H818P Lollipop and MarshMallow Upgrade to Nougat

Hi Guys,

I recently got an LG G4 H818P running Lollipop and decided to upgrade to MarshMallow via OTA. I couldn't root it or upgrade to Nougat so I downgraded to Lollipop then followed [MENTION=5750161]hochocnua[/MENTION]'s tutorial to accomplish this. I struggled with some of the instructions so I recompiled his instructions for Downgrade and Upgrade

I experienced problems when trying to downgrade from Nougat to MarshMallow and the phone was stuck in Download Mode. LGUP failed to install all TOT or KDZ files I could find usually failing at 11%, 18%, 25% or exiting with an error 0x2000. LG Flash Tool 2016 and LG Flash Tool 2015 failed to recognise COM ports. LG Flash Tool 2014 recognised ports and began installation but failed with an error "unable to connect to server" or "an unexpected error occured".

I have a written process made by Raspberry Junto Pi(http://raspberryjuntopi.xp3.biz/2017/10/13/off-downgrade-lg-g4-do-nougat-para-o-marshmallow/). This guide is for everyone who has experienced any of these problems:

Downloads:

LGUP: https://mega.nz/#!VxhwnTjI!fxDhqUjFpPEZioExIlR1xnA8Zm8bcrfNucXHCt-ehV4

LG Drivers: https://mega.nz/#!s8ATVboQ!LOeFQZB6XG7Vgz8ni33RjuPK9IjUcRPT_n4eVUHD6rE

Modded KDZ file: https://mega.nz/#!VlQkCL5J!4RYdutBSrrGiDMO0Kur9LbY74PdwZ0-tsvW-XS0zVNs

Step 0: Unbricking Process

1. Install LG drivers

2. Install LGUP 8994 DLL then LGUP v1.14.3

3. Connect the phone in Download Mode

4. Launch LGUP

5. select "Upgrade" option

6. Load the modded KDZ file

7. SELECT "REFURBISH" OPTION

8. Click "start" and leave the phone connected until it reboots and loads the OS

NB:This proccess will land you in MarshMallow. If you wish to upgrade to Nougat, follow [MENTION=5750161]hochocnua[/MENTION]'s recompiled process below

PREPARATION

PC

Download all files listed and put them in a folder. Choose either of the Rooted Lollipop files according to your version and proceed

Install LG Drivers

Install LG UP. First install the DLL file first then the LG UP file

Phone

On your phone, go to Setting> About Phone> Common> Software Info> Build Number

Click on "Build Number" till it says " You are now a developer"

Go back to Setting Home> Developer Options

Turn on USB Debugging

PC

Go to The Folder with all the files> then LG_Root folder

Right click while holding the "Shift" key

Click "Open command window here"

In the command prompt, type "adb devices".

In the pop-up window on your phone, check the "always allow this computer"

INSTALLATION

Step 1: Downgrade to Android 5 (Lollipop)

NB: if you are running Android 6.0 (MarshMallow), you have to downgrade to Android 5.1 Lollipop; if not proceed to Step 2

1. Put phone in download mode

2. Launch the LG UP and load the Lollipop KDZ file

3. Select the "Upgrade" option

4. Click start. The installation will be fast but the booting up may take some time (if it's stuck on LG logo, hard reset it_

5. After bootup, ensure USB debugging is on and functional

Step 2: Rooted/Installing Rooted OS

1. Go to The Folder with all the files> then LG_Root folder

2. Right click while holding the "Shift" key

3. Click "Open command window here"

4. Launch the "ports" script

5. Note down the COM port listed alongside "LGANDNETDIAG1" (eg COM12) and do not close it

6. In the previous command window, enter "Send_Command.exe \\.\COMxx" without the quotes eg Send_Command.exe \\.\COM12

7. Type "id" and hit enter

8. Then type: dd if=/data/media/0/system.rooted.H81510c-EU.img bs=8192 seek=55296 count=529920 of=/dev/block/mmcblk0

9. It should take some time. if it happens in a few seconds, you aren't doing it right

10. After it is done, type "LEAVE" and hit enter. Your phone should now reboot.

Step 3: Installing Android 7 (Nougat)

1. Install Flash Fire.apk

2. Launch it and grant superuser access

3. Copy the Nougat zip to root of internal storage

4. Press the "+" and select the "Flash ZIP or OTA"

5. Navigate the internal memory, select the Nougat zip

6. Then select the "Flash" option

7. It will reboot and flash the ROM. First bootup will take some time so be patient.