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
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?
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
You cannot enable/disable bands on the H910 sadly using the LGMENU dialer code..
runningnak3d said:
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).
Click to expand...
Click to collapse
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!
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
XblackdemonX said:
You cannot enable/disable bands on the H910 sadly using the LGMENU dialer code..
Click to expand...
Click to collapse
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.
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
Question about modem/data
runningnak3d said:
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
Click to expand...
Click to collapse
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?
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
runningnak3d said:
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
Click to expand...
Click to collapse
Unfortunately I didn't back up. Checking the procedure I followed it didn't tell me to (https://www.google.com/amp/s/forum.xda-developers.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.
wren2k said:
Unfortunately I didn't back up. Checking the procedure I followed it didn't tell me to (https://www.google.com/amp/s/forum.xda-developers.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.
Click to expand...
Click to collapse
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.
@wren2k Those files are unique to your phone, and I have no idea how to recreate them.
-- Brian
@runningnak3d
can you check pm of the modems im using.
@runningnak3d
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 ....
Modem bands
I have lg stylo 3 plus tp450 do you have the please let me know I have absolutely stock firmware 10c thanks
spacebound88 said:
I have lg stylo 3 plus tp450 do you have the please let me know I have absolutely stock firmware 10c thanks
Click to expand...
Click to collapse
This is the v20 forum, suggest you search your models forum for modem files
Sent from my LG-H910 using XDA Labs
Lg vs995 no coverage in Ireland
runningnak3d said:
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
Click to expand...
Click to collapse
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
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
runningnak3d said:
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
Click to expand...
Click to collapse
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