yashsingh1/xdaforums huggingface dataset:
[LG V20 Guides, News, & Discussion] runningnak3d:
I am writing this because I see several people are having problems getting their phone to work on certain carriers.

There are four MAIN parts to an Android phone communicating with a cell network:

1 - The hardware modem itself. All MSM CPUs (MSM8996 in our case) have the same modem. It is built into the CPU. From the factory it is capable of talking on all 2G, 3G and 4G bands. However, there are QFPROM qfuses that can disable parts of the modem. These can be blown by the OEM or the carriers (if the phone is carrier branded).

2 - The modem firmware. This runs in the TZ and receives calls from the RIL -- they are AT commands just like an old school modem.

3 - The RIL (Radio Interface Layer). This runs as rild inside the Android OS, and is what things like the dialer or your SMS app talk to. All commands and voice paths are sent to this.

4- The antenna. Even if you have the ability to enable all bands, you probably don't have the antennas needed.

So, how do you know what is the limiting factor for your phone talking on a particular band? Trial and error.

First the hardware modem. If there are qfuses blown that disable bands -- there is NOTHING you can do about it. There (currently) is no way to check this, so you won't know until you try some of the software methods.

Next, the modem firmware. It is signed, so you can't just flash ANY firmware from any vendors phone. Now, on the V20, since LG screwed up, we can flash the modem from pretty much any model V20 onto any other model V20 (H918 being an exception). However, modem is also checked for ARB. So, if you are ARB 0, and you flash an ARB 1 modem, your ARB will be incremented and then you MUST run a full ARB 1 firmware stack. In the case of the H910, there is NO ARB 1 firmware stack -- so you have just toasted your phone. If you are ARB 1, and you flash an ARB 0 modem, you will get the "green screen of death". It won't brick your phone, but it won't boot till you flash a KDZ (or recover it with some other means).

So next up with have the RIL. This is actually the safest thing to test. Carriers CAN block bands at the RIL level. Replacing the RIL is simple, and won't brick your phone. Now, I say they CAN, but you won't know till your try. Flashing the system partition from another model that you CAN talk on the bands you want is the easiest way. However, your phone may not boot till some tweaks are made. This is completely safe though as long as you have a FULL backup of your phone. I don't mean a TWRP backup. I mean a dump of EVERY SINGLE partition (you can leave our userdata).

That leaves antenna. Even if you can unlock the bands, if you don't have an antenna for that band, you aren't talking.

So, before you guys go breaking your phones trying to unlock bands, do yourselves a favor and try the safest method first. If you want to flash modem firmware, and you aren't sure, send me a PM with the modem you have, and what you want to flash. I will tell you if it is at least not going to brick your phone.

-- Brian
[LG V20 Guides, News, & Discussion] Sourav_GangstaYayo:
I have been searching on for trying to unlock bands and I can't seem to find any. Would you be kind enough to point me at a direction?
[LG V20 Guides, News, & Discussion] runningnak3d:
I have never needed to unlock bands, so I don't know the exact procedure. I know that in the service menu you can enable / disable bands. I don't know if it is the standard LGMENU dialer code, or some other code -- do a search, and you can find it.

As for replacing rild. That would require you to unpack the system images of your phone and the phone you want to replace it with. But (AFAIK) you can't just replace rild, there are shared libraries, and config files, and then your would probably have to update your audio path conf, and maybe even replace your dialer. It takes work :)

Flashing the modem firmware is the easiest, but you have to be careful as was stated above.

-- Brian
[LG V20 Guides, News, & Discussion] XblackdemonX:
You cannot enable/disable bands on the H910 sadly using the LGMENU dialer code..
[LG V20 Guides, News, & Discussion] Boxy52:
When you say H918 being an exception - are you saying you can't flash H918 on other phones, or can't flash other phones on H918?

I would very much like to flash the H918 modem on my H990DS to see if that gets VoLTE/WiFiCalling working, if that's possible.

Thanks!
[LG V20 Guides, News, & Discussion] runningnak3d:
You can't go either way. All models of the V20 (that I know of) have the same RSA key in the CPU to verify the signature of the firmware with the exception of the H918. If you flash any SIGNED H918 firmware onto any other model, then at best it won't boot, and at worst, it will brick your phone.

-- Brian
[LG V20 Guides, News, & Discussion] Sourav_GangstaYayo:
Agreed. At&t has disabled those options in this device.

---------- Post added at 01:27 PM ---------- Previous post was at 01:26 PM ----------

Can I flash the international varient modem firmware into this device? 91010i software here.
[LG V20 Guides, News, & Discussion] runningnak3d:
The hidden menu options are disabled at the OS level.

As I stated, it is perfectly safe to flash another model's system image and see if it will boot. Flash system from a model that you know has access to enable / disable bands. If you can get that much working, then you can work on hacking together a system image that is fully functional. Heck, you may be surprised and get what you want without having to make any other changes.

However, make SURE you have backups of modemst1 and 2, misc, persist, and persistent.

-- Brian
[LG V20 Guides, News, & Discussion] wren2k:
Question about modem/data

Brian,

You seem fairly knowledgeable so I'll see if you have an answer for me. I rooted my ls997 when it was on zv7 which involved flashing a KDZ using patched LGUP. After that I was not able to connect to LTE. I have looked at numerous settings, flashed the zv5 modem image file, flashed several roms, updated profile and PRL. I'm currently on a stock ls997 rom with a custom kernel and mms, calls, and 3g data work fine but no LTE. Any ideas?
[LG V20 Guides, News, & Discussion] runningnak3d:
Hopefully you backed up your phone like the Zv7 root procedure said ;)

If you have modemst1 and st2 -- flash those. You can flash them from fastboot:

fastboot flash modemst1 modemst1.img

fastboot flash modemst2 modemst2.img

Part of the root procedure for Zv7 involves flashing the VS995 KDZ. When the phone boots, there is data that gets written to those two partitions.

Restore them from backup, and LTE will be back.

-- Brian
[LG V20 Guides, News, & Discussion] wren2k:
Unfortunately I didn't back up. Checking the procedure I followed it didn't tell me to (https://www.google.com/amp/s/xdaforums.com/v20/how-to/root-ls997-to-zv9-t3696488/amp/) I'll make a post in the thread asking the op to update the procedure so others will not be in my situation. At least now I know which files I need to find. Thank you.
[LG V20 Guides, News, & Discussion] wren2k:
On that note if anyone reading this forum happens to have those files so I can flash them if you would upload them I would greatly appreciate it.
[LG V20 Guides, News, & Discussion] runningnak3d:
[MENTION=2721184]wren2k[/MENTION] Those files are unique to your phone, and I have no idea how to recreate them.

-- Brian
[LG V20 Guides, News, & Discussion] darkknight200:
[MENTION=3167089]runningnak3d[/MENTION]

can you check pm of the modems im using.
[LG V20 Guides, News, & Discussion] JODA-5000:
[MENTION=3167089]runningnak3d[/MENTION]

Could you please share with me the QCN of the H910 or tell me where I could find it?

My computer has no signal or bluetooth, but imei and baseband are fine.

They told me that you only need to flash that to make it perfect.

Thank you very much and I hope you save me ....
[LG V20 Guides, News, & Discussion] spacebound88:
Modem bands

I have lg stylo 3 plus tp450 do you have the please let me know I have absolutely stock firmware 10c thanks
[LG V20 Guides, News, & Discussion] cnjax:
This is the v20 forum, suggest you search your models forum for modem files
[LG V20 Guides, News, & Discussion] marcmcw:
Lg vs995 no coverage in Ireland

Hi Brian,

Thanks for your informative post you seam to be very knowledgeable on this subject unfortunately I am not. Would you be able to help me or point me in the right direction I bought an lgv20 vs995 and I live in Ireland, the phone is lovely but I can't seam to get 2g signal on it. I can get 3g and 4g but its not great when I do if I compare to my lg g5. I have tried unlocking the bootloader and flashing lineage 14.1 but didn't help. Would you be able to tell me which version of the lg v20 would work best in my country and how would I go about flashing to its baseband?

Thanks a million,

Marc
[LG V20 Guides, News, & Discussion] runningnak3d:
Since you have a VS995 that has a KDZ so you can return to stock very easily, try them all, just make sure you backup modemst1 and 2, and misc before you start.

Also, do not flash H918 or any zips from LS997. Other than that, grab a KDZ, flash it, and see.

I would start with the H915, or US996. Then try the F800. If you don't care about root for now, you can use the F800 Oreo KDZ if you want Oreo.

The H990 is another one, not the H990DS.

If you find one that works, I can help you make a flashable zip that will let you keep root if you decide to root again based on the model that works for you.

At the end of the day though, it could be the VS995 radio just isn't good for 2g in your area.

Let me know.

-- Brian
[LG V20 Guides, News, & Discussion] marcmcw:
Hi Brian,

Thanks for the fast reply i will try over the next few days and il update as to what works and what doesn't . Aslo quick 1 im a bit confused with this ARB0 and ARB1 is there an easy way of checking whice one my phone is?

Thanks again,

Marc
[LG V20 Guides, News, & Discussion] runningnak3d:
All LG V20s are ARB 0 except the LS997 and H918.

On top of that, LG UP won't let you flash a lower ARB version.

-- Brian
[LG V20 Guides, News, & Discussion] marcmcw:
Hi Brian,

Thanks for the info im having an issue with lgup im trying to install h990 kdz but it comes up with the following error:

KDZ file is invalid: VSS996 -> H990

[IMG="lgup error"]https://ibb.co/gayROK[/IMG]

https://ibb.co/gayROK

Should i be using lgup to reflash or lgflash tool.

Thanks,

Kindest regards,

Marc
[LG V20 Guides, News, & Discussion] runningnak3d:
You have to use the patched LG UP and use partition DL mode.

-- Brian
[LG V20 Guides, News, & Discussion] Alibaba0101:
I'm on arb0 on my h918 but i've been having a lot of signal issues using on at&t. Other than band 30 the phone is almost identical to the h910. I've been considering going back to stock to update the firmware to 10u which brings the phone to arb1, but then i can't use lineage anymore. Any thoughts or recommendations?
[LG V20 Guides, News, & Discussion] marcmcw:
Thanks For all your help Brian i managed to flash h990 h915 and f800 but im afraid the only one i could get to boot successfully was f800. It runs lovely and smooth but it wont detect my sim now at all. Im assuming i now need to restore both modemst1.img and modemst2.img to get it to work again?

Cheers,

Marc
[LG V20 Guides, News, & Discussion] runningnak3d:
It won't detect your sim because of the modem.

You can try flashing your Nougat modem, but the rild may not talk to it.

If you want to try, grab you H990 KDZ and use partition DL, and only check the modem.

Again, the worst that happens is that it doesn't boot or work if it does boot, and you have to flash the whole H990 Nougat KDZ.

-- Brian
[LG V20 Guides, News, & Discussion] darkknight200:
questions about h915 using h910 and potentially h915 oreo

So my dirty santa h915 has been using us996 roms like alpha and super rom for awhile with full signal and everything.

Today I decide to try out h910 rom from alpha and everything booted up fine but I had no data. I flashed the most current modem 10v and then tried a few h915 modems I had from kdz. All failed at getting signal on my h915.

So then i went back to us996 rom again with us996 modem and I had full signal again

So correct me if im wrong but this is my understanding. So my dirty santaed h915 wont get signal on h910 roms but only with us996 roms because the eng bootloader is us996?

Another question that I have is the h915 oreo that I pulled is if I use patched lgup and selectively flash everything but aboot and recovery like those h910 testers, I should get working data modem because my device is real h915?

Or would I have to wait for us996 oreo to drop to continue to use my h915 with dirtysanta with working data?
[LG V20 Guides, News, & Discussion] :
So i been messing my phone a little bit flash h915 oreo kdz without modem but no signal and i flash back to us996 to do dirtysanta then flash super rom now my data sometime has lte sometime it drop down 3g then 1x could possibly the modem but i download modem img flash it in twrp but seem it not work...anyway i has vs995 used Verizon sim..
[LG V20 Guides, News, & Discussion] aegli214:
I'm planning on buying an LG V20, but I'm having problems understanding if the H910 or H918 can do what I what it to do. Ideally I want to be able to unlock the bootloader + root, and also have it work with Freedom Mobile's Band 66 LTE. Apparently the H918 and H910 doesn't work on Freedom Mobile's Band 66 LTE, even though they are supposed to support it. I've seen people here talking about flashing their H910 to a H915. My current understanding:

H918 -> Rootable + Bootloader Unlock, no Freedom Band 66, cheap to buy.

H915 -> Not rootable, has Freedom Band 66, expensive.

H910 -> Flashable to H915, may be rootable (depends on FW version it's shipped with), might work with Freedom Band 66 after flash?

Anyone have any tips for me?

Thanks!
[LG V20 Guides, News, & Discussion] darkknight200:
H915 is the device with band 66 that works on freedom mobile.

It is rootable. Its just that you have to use us996 rom once rooted. I have full lte with freedom mobile on my h915 with us996 rom. Band 66 is available on us996 rom of the h915 device.

The only downside is no wifi calling which I can live with.
[LG V20 Guides, News, & Discussion] aegli214:
That's good to know, thanks! I just looked and the H915 is more than 2x the price of the H910. Has anyone successfully flashed a H910 to a H915 and verified band 66 works on freedom? Is there any reason it wouldn't?
[LG V20 Guides, News, & Discussion] darkknight200:
I don't think there's much h915 users here besides me.

O wow that's weird that the Canadian h915 is expensive at this time of the year.

But your best bet to have band 66 with freedom mobile is the h915 since that was the device model that was advertised for when LTE rolled out.
[LG V20 Guides, News, & Discussion] buyaodanxin:
Hi,

I have put a V995 KDZ on my V995S (note the S) Phone. I was trying to upgrade

I no longer have cell coverage.

Can I burn a modem from another ROM to my phone without bricking it using LGUP ? If so which is most likely to work ?

Thanks,

Rob
[LG V20 Guides, News, & Discussion] itchydroid:
Upgrading the modem firmware beyond H918 10p?

Can I upgrade JUST the modem firmware from newer KDZ files?

- I have a H918 that was downgraded to 10p

- Bootloader has been unlocked; TWRP installed using lafsploit

- Stock rom removed and currently running latest Resurrection Remix ROM, root, gamma kernel.

As the newer KDZs contain newer images for the modem firmware (such as those from 20g), can I install the modem firmware from 20g and still have calling/mobile data? I ask because theres a thread somewhere here regarding extracting the modem firmware from KDZ and installing it. Just wondering it will work for the situation above. Thanks
[LG V20 Guides, News, & Discussion] runningnak3d:
You can try, but keep in mind that the modem firmware is for more than just the modem -- for example, the fingerprint sensor.

Usually -- and I want to emphasize USUALLY if you flash modem firmware that is too old or too new -- as long as ARB and RSA match, you will just get a green screen of death, but you can still get to TWRP or download mode to fix your phone. However, there is a chance that you can get into a situation where you can't that phone to boot at all, and since the H918 doesn't have full fastboot, you are stuck.

-- Brian
[LG V20 Guides, News, & Discussion] itchydroid:
Thanks for the clarification. I'll leave this experiment to some other brave soul as the v20 is my daily driver. :D
[LG V20 Guides, News, & Discussion] aximrocks:
hi brian,

I'm in Canada on Rogers network. bought my unlocked H910 from eBay. I flashed Alpha Omega oreo rom and get the "no sim detected" error, no signal, no service, radio is off. so I fastboot flashed modem firmware from my Nougat backup, radio works now, but the fingerprint stops working. I had the same problem with Nougat rom. the stock AT&T modem firmware isn't working for some reason. the only fix is to fastboot flash the modem from my backup. this works fine on Nougat, but not oreo. do you know where can I download the proper modem file for my phone? here is the link to the modem file from my Nougat backup. baseband version MPSS.TH.2.0.1.c3-00011-M8996FAAAANAZM-1.68646.1.69323.1

https://ufile.io/z01ke
[LG V20 Guides, News, & Discussion] runningnak3d:
[MENTION=4126391]aximrocks[/MENTION] You followed the instructions in the Alpha Omega thread on how to get a the FP sensor working? Because the modem firmware is also the interface to SFS, you have to flash stuff in a particular order.

Check the instructions again.

-- Brian
[LG V20 Guides, News, & Discussion] furryfella:
Hi folks,

My question is in regard to having no network connection and the settings in my H910 V20 reporting the radio is off.

Is there any way to confirm if the radio/modem is dead (i.e. that this is a hardware problem?) The wifi is working fine, is that part of the modem?

I have the correct baseband and IMEI, and a H910 .qcn file. To reinstate the baseband and IMEI, I had to erase modemst_1 and modemst_2 and fsg partitions before restoring using .qcn file. Are there other partitions I should erase and flash such as misc, persist etc? Could these perhaps be messing with the radio/modem?

I have read of many instances like mine where the radio was off but no one seems to have really found soloutions. Occasionally different ROMS bring the radio back on but only in isolated cases.

Ive searched high and low to find any soloution or and way of diagnosing or troubleshooting the x12 modem but havent got anywhere. Does anyone have any ideas or speculations?

Regards, Chris
[LG V20 Guides, News, & Discussion] emdroidle:
I'm rather suspicious of the statement that they're efuses. Actual fuses couldn't be unblown, yet for the V10 it was done. Worth noting that /sys/devices/platform/lg_diag_cmd/diag_enable exists on the V20, including in LineageOS so I'm rather wanting to try the method on a V20.

Unfortunately I'm rather suspicious the link to CDMATool in that post is an illegal cracked copy. That is some nice functionality and I would like to see some money going back to the original developers. :(

Hmm, the green screen is modem ARB? Sounds like you've got some means to check the ARB level of firmwares? Might I inquire what that is?

I managed to reliably trigger a green screen a few days ago... I flashed the modem firmware from a 20a KDZ to a device running LineageOS. I finally went back and flashed the modem firmware from a 10g KDZ and everything returned to how it had been. If a fuse had been blown, going back to the older firmware wouldn't have worked. I'm pretty sure there was a mismatch, but no ARB fuses.

I'm generally in favor of running later firmwares as that generally gets you security updates, but if that isn't possible...
[LG V20 Guides, News, & Discussion] skeevs:
I have a network unlocked H910 but can only get network signal with this baseband MPSS.TH.2.0.1.c3-00011-M8996FAAAANAZM-1.68646.1.69323.1

Checking on AT&T website, this is not their baseband.

Any idea I can work out with model this baseband is actually for ?

I can't get fingerprint working in Oreo because I need to use because I only have the backed up modem partition for Nougat.

Thanks.
[LG V20 Guides, News, & Discussion] warwagon19792:
I have a vs995 (verizon) currently on the Lineage v16. The modem I currently have is from December 2016 when I rolled the phone back to dirty Santa the phone. I keep roaming randomly around town and when that happens I can't make a call. Someone suggested it's because I have the old modem firmware from 2016. I just don't know what to safely flash. I was wondering if someone could point me to a file to flash via TWRP to update the modem to the latest compatible version for Lineage 16.
[LG V20 Guides, News, & Discussion] koodz:
Hey [MENTION=9808726]skeevs[/MENTION] I know it's a few months late for you, but I just spotted your post and wondered if this thread I made might be able to help you. I was having the same problem with the fingerprint scanner in Oreo.

I didn't go into checking baseband info but found a way around it by mashing the oreo modem files with my backed-up nougat modem and currently have everything working well. Let me know if it works for you, if you try it!
[LG V20 Guides, News, & Discussion] skeevs:
[MENTION=10139265]koodz[/MENTION] a couple months late in much so that I've given up with the V20 and went for a V30+ just 3 weeks ago! This post that you linked is fantastic! I'd wish it was around months earlier! I'm surprised how quick the months went by though. I did get to the point of realizing the difference between the modem files of nougat and oreo. Opened up in hexeditor but had no idea they were "mountable" :) Great work in finding out.
[LG V20 Guides, News, & Discussion] koodz:
[MENTION=9808726]skeevs[/MENTION] haha yes I'm a few months behind the crowd unfortunately. I got my v20 about three weeks ago too, brand new for about 150€. Anyway hopefully that post will help some other latecomer - it was a great learning exercise in any case, and a good insight into all the effort people on this forum put into helping others, seeing how time-consuming it is. Hope you are enjoying the v30 experience!!

---------- Post added at 03:30 PM ---------- Previous post was at 03:29 PM ----------

[/COLOR [MENTION=9808726]skeevs[/MENTION] haha yes I'm a few months behind the crowd unfortunately. I got my v20 about three weeks ago too, brand new for about 150€. Anyway hopefully that post will help some other latecomer - it was a great learning exercise in any case, and a good insight into all the effort people on this forum put into helping others, seeing how time-consuming it is. Hope you are enjoying the v30 experience!!
[LG V20 Guides, News, & Discussion] tarpaga:
After some readings here and there, this is what restored my network signal :

fastboot flash modemst1 modemst1.img

fastboot flash modemst2 modemst2.img

fastboot flash modem modem.img

This post helped me a lot.

I have a H910 on which I installed the oreo US99620f_00_1120 using the patched LGUP. I lost network signal.

I have made a dump of everything except system (modem, modemst1, modemst2, boot, misc, persist, persistent and recovery)

I managed to install TWRP using the Dirty Santa method but unfortunately, flashing the modem couldn't restore signal.

I guest it has something to do with the ARB 1, so I am about to install the H910 oreo following this guide

I'll give update about it soon but if I am about to do something that could harm my device, I'll be grateful.