[LG V30 ROMs, Kernels, Recoveries, & Other Developm] jorddenn:
I've spent the last three days trying to sort out how to get mobile data data back after converting to US998 and then back to H933. The information is fragmented and a clear process isn't in one place, plus I found that the process can be shortened a fair bit.

This guide assumes your bootloader is already unlocked, as it almost certainly must be to need this guide.

This guide cuts down several other guides by removing unnecessary steps, those guides, marked Relevant, will be linked and they should all be read before starting.

This guide is based on [MENTION=9596895]Homer14061[/MENTION]'s post here

This will take about 2 hours.

BACKUP ALL DATA BEFORE PROCEEDING

ALL DATA WILL BE LOST

Files needed:

US998 Nougat KDZ - US99810C_03_1216.kdz

H933 Oreo KDZ - H93320H_00_OPEN_CA_OP_1123.kdz

LGUP & LG USB Drivers

LGUP Dev Patch - LGUP&V20dll_Patched.zip

LGUP_common_DLL_V30_ALLVARIANTS.zip

TWRP (select which type you want, guide will refer to either as 'twrp.img')

lg-rctd-disabler-1.0.zip & no-verity-opt-encrypt-6.0.zip & Magisk-v18.0.zip

For ADB I recommend this but if you need this guide you would already have it

Step 0 - Prep

Install LG mobile drivers, LGUP and ADB if you haven't already

Patch LGUP by extracting the LGUP&V20dll_Patched.zip into the LGUP install directory, overwriting the EXE and adding the folder structure for common DLLs

Replace the V20 DLL in the /model/common folder with the one from the LGUP_common_DLL_V30_ALLVARIANTS.zip

Step 1 - Restore H933

If you already have a DUMP from H933 firmware with working data, move to Step 3

Connect phone to patched LGUP

Select REFURBISH

Load H933 KDZ

Start

You should have mobile data again however no TWRP and no root

Step 2 - DUMP partitions

You may need to re-enable ADB Debugging before continuing

Close LGUP and disconnect phone

Reopen LGUP and reconnect phone

Select DUMP

Start, select all then select a folder for the files to be dumped to

This should take about an hour with all partitions selected. Only 9 are needed however, it may be useful in the future to have all of them.

The 9 that are needed are OP, modem, modemst1, modemst2, misc, persist, ftm, pstore, recovery.

Mine always ended in a timeout error however that seemed to not be a problem.

Remove "_COMX" and add ".bin" to the 9 files.

Now is a good time to copy these 9 files along with lg-rctd-disabler-1.0.zip, no-verity-opt-encrypt-6.0.zip and Magisk-v18.0.zip to your External SD if you have one, otherwise they can be pushed later.

Step 3 - PARTITION DL US998 (Relevant)

Close LGUP and disconnect phone and restart

Reopen LGUP and reconnect phone

Select PARTITION DL

Load US998 KDZ

Start, Select All, Yes to partition changes window

When its done it will attempt to boot and you'll get flashes of an image, perform Master Reset

Step 4 - Flash TWRP (Relevant)

Get through setup screens

Enable ADB

In Command Prompt ->

adb reboot bootloader

Once rebooted ->

fastboot flash recovery path/to/twrp.img

Once completed ->

fastboot boot twrp.img

Swipe to allow modifications

Wipe -> Format Data -> yes

Wipe -> Factory Reset

Reboot -> Recovery

Unplug the cable

Reboot -> Power Off

Step 5 - PARTITION DL H933 (Relevant)

Enter Download Mode (Hold Vol + and plug in cable)

Open LGUP

Select PARTITION DL

Load H933 KDZ

Start, Select All, UNSELECT Recovery, Yes to partition changes window

Your phone should reboot to TWRP when finished

Step 6 - Fix Partitions (Relevant)

Swipe to allow modifications

Wipe -> Format Data -> yes

Wipe -> Factory Reset

Reboot -> Recovery

If you copied Magisk-v18.0.zip, no-verity-opt-encrypt-6.0.zip and lg-rctd-disabler-1.0.zip to an External SD then flash them now, in that order

Otherwise

adb push path\to\Magisk-v18.0.zip /sdcard/
adb push path\to\no-verity-opt-encrypt-6.0.zip /sdcard/
adb push path\to\lg-rctd-disabler-1.0.zip /sdcard/

then flash them in that order

If you copied the 9 .bin files then Advanced -> File Manager

Copy each .bin to /sdcard/

Otherwise

adb push path\to\OP.bin /sdcard/
adb push path\to\modem.bin /sdcard/
adb push path\to\modemst1.bin /sdcard/
adb push path\to\modemst2.bin /sdcard/
adb push path\to\misc.bin /sdcard/
adb push path\to\persist.bin /sdcard/
adb push path\to\ftm.bin /sdcard/
adb push path\to\recovery.bin /sdcard/

In Comamnd Prompt ->

adb shell
dd if=/sdcard/OP.bin of=/dev/block/bootdevice/by-name/OP
dd if=/sdcard/modem.bin of=/dev/block/bootdevice/by-name/modem
dd if=/sdcard/modemst1.bin of=/dev/block/bootdevice/by-name/modemst1
dd if=/sdcard/modemst2.bin of=/dev/block/bootdevice/by-name/modemst2
dd if=/sdcard/misc.bin of=/dev/block/bootdevice/by-name/misc
dd if=/sdcard/persist.bin of=/dev/block/bootdevice/by-name/persist
dd if=/sdcard/ftm.bin of=/dev/block/bootdevice/by-name/ftm
dd if=/sdcard/pstore.bin of=/dev/block/bootdevice/by-name/pstore
dd if=/sdcard/recovery.bin of=/dev/block/bootdevice/by-name/recovery

Unplug phone

Reboot -> Power Off

Power On

Should briefly see the same erasing circle from Master Reset

You should now have mobile data again.

Step 7 - Clean Up

Get through setup screens

Enable ADB

Plug in

In Command Prompt ->

adb push path\to\twrp.img /sdcard/
adb shell
su
dd if=/sdcard/twrp.img of=/dev/block/bootdevice/by-name/recovery

Install Magisk Manager (it always needed a reboot after installing manager app to finish installing)

Step 8 - Profit and enjoy!

Thank you to:

[MENTION=3250376]ChazzMatt[/MENTION]

[MENTION=3138121]seadersn[/MENTION]

[MENTION=4160343]cloud1250000[/MENTION]

[MENTION=9596895]Homer14061[/MENTION]

and the people and teams whose posts and files I've linked here as well