[LG V20 Questions & Answers] Descent2:
Welcome Back Supovitz!

I am a newbie for V20, and looking to answer the same question as you, plus how to root. By writing out my small collection of knowledge in response to your question, I hope to help myself first, to organize and bake -in my knowledge so that it becomes useful to me and starts making sense. But keep in mind that I am a newbie.

MODEL AND VERSIONS

You can find the exact model here (from your IMEI):

Google

Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for.

lg-roms.com

Mine is listed as H918 on the label behind battery, but the http://lg-roms.com/ gives me H918TN

(I do not know if this difference is significant, however, elsewhere on this forum there is a lot of warnings that specifically with H918 there should be NO CROSSFLASHING, the model number must match - or BRICK.)

For H918 what matters is what ARB version your phone is on (ARB=AntiRollBack):

Nougat was ARB0 then ARB1, Oreo is ARB1 so far.

These ARB versions are loosely associated with the phone software versions such as 10j, 10p or 20h and so on.

Look at this page to get an idea when these software versions were released and how many of them are there:

LG H918TN(LGH918TN) aka LG V20 - LG-Firmwares.com

LG H918TN download the firmware for free! Detailed installation instruction. Video review of the model and its features. User feedback and latest news.

lg-firmwares.com

To find ARB and Software version, you can use the about phone info in settings (at least for H918 they are visible):

View attachment 5361431

View attachment 5361433

Mine is running Nougat Android v7, software version 10j (ARB0)

Another way isto check by entering the dial code:

dial: *#LGMENU#*model# ( *#546368#*918# )

choose SVC Menu

choose Version

scroll to bottom

Thus for H918 there have been two ARB versions, 0 and 1 so far:

ARB0 - 10a - 10o

ARB1 - 10p - 10u

The point of knowing the ARB version is that there are two rules:

- if you flash a ROM for a lower version of ARB than the device shows, this will brick your device

- once you flash a ROM that has a higher version than what the device is currently on, ARB adjusts irreversibly

This is why the Anti Roll Back, - we can only move up in software versions, once we discover a root, they issue a new version and severely reduce the number of devices for sell that could use that discovered root.

( there is an actual fuse on the SOC that is burned, and this cannot be ever restored )

So this needs to be considered when choosing a ROM.

TOOLS INVOLVED, TIPS AND LIMITATIONS

Another thing you need to know about H918, is that you cannot count on FASTBOOT flash command on H918. These important FastBoot commands were disabled by T-Mobile. The only use for the fastboot remains on H918 is to unlock the bootloader / check if it is unlocked, i.e. fastboot oem unlock and fastboot getvar unlocked

Searching for a way to flash our files to the H918, XDA RunningNak3d created a method to exploit the "Download Mode" (hold VOL+ insert USB cable to enter the DM) present on H918 which is there to allow for the "LG Advanced Flash".

(I do not know why we can't just use that LG Advanced Flash tool to push our images, such as TWRP? I am sure there is a reason)

Now this exploit allows us to place a TWRP onto the LAF partition (where the Download Mode binary normally is) and thru that TWRP gain an ability to flash images rather than using the the LGUP tool (is LGUP the same as LG Advanced Flash " tool ?). IIRC, the LGUP does have some sort of control what is it asked to flash, so may-be this is why we can't use LGUP to flash TWRP onto Recovery partition and be done with it. So , we use the LAFSPLOIT.

To use LAFSPLOIT you would need to have a prepared linux environment to run the script by the RunningNak3d. There is a prepared bootable ISO image of such environment complete with many tools and LAFSPLOIT and also the ADB called FWUL. Once you get the TWRP on LAF, you typically use it to flash another TWRP, this time to Recovery partition, flash LAF Partition back if you want a working Download mode, and also flash your ROM and your chosen ROOT thingy.

With this it is important to note that H918 has some intricate issue that has to do with encryption. As you know you first Encrypt and then you Root, if you want to have the encryption.

Look at the currently ongoing attempt by XDA PineappleMousepad to ROOT the H918 and keep the Encryption here: https://xdaforums.com/t/h918-rooted-and-encrypted-on-stock.4302253/

But there is this issue with booting to system from TWRP on a stock based ROMs (as opposed to AOSP, for instance). The issue is that the phone goes into the bootloop on SecureBoot (aka DM-Verity), trying to decrypt the DATA partition. To prevent this you must remember to do an advanced wipe from TWRP, before it had a chance to boot to system! So you Reboot to Recovery / and/or use hardware buttons to reboot to recovery, and you have you back cover off, standing ready to pull the battery if you think the phone boot process is going to miss the recovery.

The wipe (format ?) of data (and some say data and cache, some say data system and cache, again needs more research)(Some recommend now to boot to TWRP again and do a full format ? - 3808258 post #1) partition must be the advanced one, - where you have to type YES to confirm. As you can tell my understanding of this aspect is very cloudy, research this.

Finally, when you use the hardware button combination to enter the TWRP that is on the Recovery partition, the process had to be made such that it appears you are about to factory reset your phone. But, no, this is how you actually enter that TWRP. See bolow in BUTTONS section.

BUTTONS

Shutdown:

Hold POWER button for 10 sec

Exit from any Mode:

Hold the [POWER] until reboot

Factory Reset / Recovery Mode:

Shutdown > [VOL-] & [POWER] few seconds (10) > LG-Logo > release [POWER][if not working try releasing both] (only let go of the power button for half a second) but keep [VOL-] > [POWER] once more > Release all once in

Factory Recovery Mode

Note: Accept the factory reset prompt using the hardware buttons. (YES two times) This will not actually reset your device but instead will boot the custom recovery [if TWRP is isntalled on Recovery Partition]

Download Mode: (LAF mode on H918 aka LG Advanced Flash)

Shutdown > Plug one end of cable to PC > while [VOL+] connect other end of cable to phone > Release once in Download Mode

Note: You will enter the TWRP LAF Version if it is installed onto the LAF Partition

Bootloader Fastboot Mode:

Shutdown > Plug one end of cable to PC > while [VOL-] connect other end of cable to phone > Release once in Bootloader Mode

FIXES

There are several fixes available for H918. I am not entirely certain what situations require these fixes, but I want to mention them anyway so that you are aware of what might go wrong.

-Thermal throttling fix

-RCTD removal

-Screen Recalibration with Kernel Auditor

-bluetooth fix? (I've seen a file but failed to findout what it is for)

-LG V30 Camera by Zacharee

-Josh Camera Mod

ROMS

I don't know a whole lot, but it seems that the Stock is the most stable, if you only want the root (like I do).

The Lineage OS has major issues, such as a dead 5G tether, dead VoLTE, No second screen, etc.

(Second screen seems to be enabled on builds of LOS and ResurrectionRemix by Blaises from XDA, but I don't think he is watching the activity here anymore. If you want those, check here:

Downloads for : LG V20 | AndroidFileHost.com | Download GApps, Roms, Kernels, Themes, Firmware and more. Free file hosting for all Android developers.

Download GApps, Roms, Kernels, Themes, Firmware, and more. Free file hosting for all Android developers.

androidfilehost.com

There is SuperV20 ROM , and again, I read there are issues, allthough, many do like it

Download: https://androidfilehost.com/?fid=673956719939834027

Discussion: https://xdaforums.com/t/super-rom-h...-vs9951ca-h990-ds-more.3764390/#post-75915485

I read somewhere on XDA and did not take a note of URL, that If the custom ROM is not stock based, you lose the great camera that V20 has. Don't know if this all the truth, nothing but the truth or what. Also, there were some fixes for the camera if flashing not a stock based rom, but did not do a great research there yet.

Obviously the WETA ROM, which was made for audiophiles and stability:

https://xdaforums.com/t/rom-kern-weta-5-0-7-16th-jun.3532778/