[GUIDE] US996 no service/radio off after OTA/KDZ fix

[ttnduy]

I've switched from my Lumia 928 to LG V20 (US996 unlocked) for 6 motnhs, and i loved it untill some **** happened. After the previous OTA update, my phone encounted radio off or no service issue. I find out this happened after reflashed the stock rom or OTA update, if you have this issue please follow these steps:
What you need:
US996 stock rom: http://lg-firmwares.com/category/lg-series/lg-v20/ (US99610f for unlocked ver.)
Patched LGUP for V20: https://forum.xda-developers.com/v20/how-to/guide-patch-lgup-to-unlock-features-t3652222
The lastest Super SU or Magisk (in case you need to pass the Safety Net for using Banking app, Android pay, etc.)
Modem file.
ADB, LG lastest driver.
I uploaded the nesscesary in here: https://drive.google.com/drive/folders/1pKKp78EqFwoCs5PuXi_2P-4_hsEx6u5_?usp=sharing
This tutorial will have 3 section: first you need to downgrade your phone to US99610f or this won't work. Next unlock your boot loader via dirtysanta n flasing TWRP. Then you flash the modem file and root your deviece with superSU or Magisk (optional).
I recommend you read this though out and pateintly following these step. You should backup your data before starting this. Do this at your own risk.
Downgrade to US99610f
If you are on the US99610n then you need to downgrade to US99610f cause you can't use dirtysanta on the US99610f (you can start from step 4 in case your phone is not soft bricked)
1. Completely Power off the v20 ( or to remove and put the battery back )
2. Plug the USB end of sync cable to your PC
3. Press and hold "Volume Up"
4. Plug in the USB-C end of sync cable to the v20. The phone will enter download mode (or Firmware Update). Now you can release the "Volume Up".
5. Run LGUP. The program will regconise the v20.
8. At the file path, click "..." and chose the .kdz file
9.Choose "UPGRADE"
10.Click "Start" and wait until the process is complete wait untill your phone boot up and there you are US99610f and still no service :silly:
Unlock Bootloader n' flashing TWRP
Turn on developer options in Settings -> About device -> Software info -> Build number. (tap 7 times or spamming it until it's enabled):laugh:
Now navigate to Settings -> Developer options -> OEM unlock. (turn it on)
Don't ever turn OEM unlock or Developer options off when using a custom ROM or recovery. This could lose to loss of all your data.
For your computer to see ADB, you will need to put the phone in Files transfer mode.

To unlock your bootloader, follow the unlock instructions on LG's site (I can't really help you there):
"This may void your warranty"
https://developer.lge.com/resource/mobile/RetrieveBootloader.dev?categoryTypeCode=ANRS
After your phone boot up:
1. copy twrp.img to your internal storage or SD card.
2. Start ADB and following these steps (just copy and paste):
https://github.com/jcadduono/android_external_dirtycow#running
3. Wait for it to complete and type:

reboot recovery

If you don't want to void your warranty please use the dirty santa by following this threat:
https://forum.xda-developers.com/v20/development/ls997vs995h910-dirtysanta-bootloader-t3519410
In this threat you will unlock you boot loader n flashing recovery. Right after you've done step 3 and your phone boot up you can wait (I dont recommend you to wait for you phone boot up, mine have screen static after that so just following these step to enter TWRP we will fix it later):
1. unplug the cable right after the logo boot up
2. remove the battery.
3. boot your phone up while holding BOTH vol down and power key.
4. Briefly release the power key right after you saw the LG logo and press it back again.
5. untill your phone boot up use vol key and power key to select yes on both screen.
6. wait for you phone reboot and now you in TWRP.
7. Select cancel if the phone ask you for password and swipe to right to allow modifications.
Flashing modem, fix screen static and other.
Now put these files in your SD card or your internal storage with mount option in TWRP (Mount=> enable MTP): Modem.img, SuperSU or Magisk, kernel and boot2.img (in adb folder).
In TWRP:
1. Tap on "wipe" => format data => type "yes"
2. Go back to home menu then select “Reboot” then “Recovery”.
3. Once rebooted, swipe to right again.
4. Tap on “Install”.
5. Choose your microSD card or internal storage depend on where you copy those files.
6. Tap on "Install Image" and select "modem.img"
7. Select "modem" and Swipe to flash.
If you use dirtysanta method you need to flash "boot2.img" to fix the screen static. Similar to flashing "modem.img" but you select "boot" before swipe to flash.
8. Go back to home menu then select “Reboot” then “System”.
Wait for your phone boot up and the issue should be fixed.
Additional things
For more advance you can flash SuperSU or Magisk if you want to root you phone for more benefit.
Flashing kernel to fix your screen retention, screen static and more ( this won't cause SafetyNet failure that mean you can use android pay and banking app).
mk2000 kernel features:
Linux 3.18.85
KCAL - Screen panel control.
ElementalX and Zzmoove CPU governors.
Modules signed and secure, as in stock rom.
Disable software CRC checking of SD Card - More performance.
Fix by emdroidle for eng-bootloader (US996Santa, H990 & H910).
CRC32 and CHACHA20 HW ACC, CRNG based on CHACHA20.
Static screen fixed (US996Santa, H990 & H910).
Many patches that improves or fixes things.
Maple I/O scheduler.
LZ4 compression.
RCTD removed.
You need to flash kernel right after SuperSU/Magisk or before you reboot to system.
Update:
in case you want to upgrade to the lastest OTA you can follow this threat:
https://forum.xda-developers.com/v20/development/rom-us99610k-stock-rom-twrp-flashable-t3691784
And you need to reflash the "modem.img".
My thanks to:
@askermk2000 for his kernel.
@jcadduono, @me2151 for rooting guide.

 

[harry.wong]

hi ttnduy, thank you for creating this thread.

my lg v20 now is no service after i update from lg bridge. before i update via lg bridge i have to upgrade via OTA but fail. then i read a message to upgrade via lg bridge.

i have some questions:

1. i missed this step : "To unlock your bootloader, follow the unlock instructions on LG's site."
so my next step is :
"github.com/jcadduono/android...rtycow#running is that right?"

then after follwing "https://github.com/jcadduono/android...rtycow#running"
my next step is :
"If you don't want to void your warranty please use the dirty santa by following this threat:"

is that right?

2. can you please explain which one i must do(copy and paste) on this step :
github.com/jcadduono/android...rtycow#running
where i run this step? is on adb to copy and paste?

thank you very much

 

[ttnduy]

hi ttnduy, thank you for creating this thread.

my lg v20 now is no service after i update from lg bridge. before i update via lg bridge i have to upgrade via OTA but fail. then i read a message to upgrade via lg bridge.

i have some questions:

1. i missed this step : "To unlock your bootloader, follow the unlock instructions on LG's site."
so my next step is :
"github.com/jcadduono/android...rtycow#running is that right?"

then after follwing "https://github.com/jcadduono/android...rtycow#running"
my next step is :
"If you don't want to void your warranty please use the dirty santa by following this threat:"

is that right?

2. can you please explain which one i must do(copy and paste) on this step :
github.com/jcadduono/android...rtycow#running
where i run this step? is on adb to copy and paste?

thank you very much

1. If you already unlock your boot loader with LG unlocked file then after you do step 3 (type reboot recovery) then you can go straight to "Flashing modem, fix screen static and other" step.
2. Here what you need to copy n paste (Running part in the link):

adb push dirtycow /data/local/tmp
adb push recowvery-applypatch /data/local/tmp
adb push recowvery-app_process64 /data/local/tmp
adb push recowvery-run-as /data/local/tmp

adb shell

$ cd /data/local/tmp
$ chmod 0777 *
$ ./dirtycow /system/bin/applypatch recowvery-applypatch
"<wait for completion>"
$ ./dirtycow /system/bin/app_process64 recowvery-app_process64
"<wait for completion, your phone will look like it's crashing>"
$ exit

adb logcat -s recowvery
"<wait for it to tell you it was successful>"
"[CTRL+C]"

adb shell reboot recovery
"<wait for phone to boot up again, your recovery will be reflashed to stock>"

adb shell

$ getenforce
"<it should say Permissive, adjust source and build for your device!>"

$ cd /data/local/tmp
$ ./dirtycow /system/bin/run-as recowvery-run-as
$ run-as exec ./recowvery-applypatch boot
"<wait for it to flash your boot image this time>"

$ run-as su
#

From your root shell, it's possible to use commands such as:

dd if=/sdcard/twrp.img of=/dev/block/bootdevice/by-name/recovery

 

[AceGed]

I've switched from my Lumia 928 to LG V20 (US996 unlocked) for 6 motnhs, and i loved it untill some **** happened. After the previous OTA update, my phone encounted radio off or no service issue. I find out this happened after reflashed the stock rom or OTA update, if you have this issue please follow these steps:
What you need:
US996 stock rom: http://lg-firmwares.com/category/lg-series/lg-v20/ (US99610f for unlocked ver.)
Patched LGUP for V20: https://forum.xda-developers.com/v20/how-to/guide-patch-lgup-to-unlock-features-t3652222
The lastest Super SU or Magisk (in case you need to pass the Safety Net for using Banking app, Android pay, etc.)
Modem file.
ADB, LG lastest driver.
I uploaded the nesscesary in here: https://drive.google.com/drive/folders/1pKKp78EqFwoCs5PuXi_2P-4_hsEx6u5_?usp=sharing
This tutorial will have 3 section: first you need to downgrade your phone to US99610f or this won't work. Next unlock your boot loader via dirtysanta n flasing TWRP. Then you flash the modem file and root your deviece with superSU or Magisk (optional).
I recommend you read this though out and pateintly following these step. You should backup your data before starting this. Do this at your own risk.
Downgrade to US99610f
If you are on the US99610n then you need to downgrade to US99610f cause you can't use dirtysanta on the US99610f (you can start from step 4 in case your phone is not soft bricked)
1. Completely Power off the v20 ( or to remove and put the battery back )
2. Plug the USB end of sync cable to your PC
3. Press and hold "Volume Up"
4. Plug in the USB-C end of sync cable to the v20. The phone will enter download mode (or Firmware Update). Now you can release the "Volume Up".
5. Run LGUP. The program will regconise the v20.
8. At the file path, click "..." and chose the .kdz file
9.Choose "UPGRADE"
10.Click "Start" and wait until the process is complete wait untill your phone boot up and there you are US99610f and still no service :silly:
Unlock Bootloader n' flashing TWRP
Turn on developer options in Settings -> About device -> Software info -> Build number. (tap 7 times or spamming it until it's enabled):laugh:
Now navigate to Settings -> Developer options -> OEM unlock. (turn it on)
Don't ever turn OEM unlock or Developer options off when using a custom ROM or recovery. This could lose to loss of all your data.
For your computer to see ADB, you will need to put the phone in Files transfer mode.

To unlock your bootloader, follow the unlock instructions on LG's site (I can't really help you there):
"This may void your warranty"
https://developer.lge.com/resource/mobile/RetrieveBootloader.dev?categoryTypeCode=ANRS
After your phone boot up:
1. copy twrp.img to your internal storage or SD card.
2. Start ADB and following these steps (just copy and paste):
https://github.com/jcadduono/android_external_dirtycow#running
3. Wait for it to complete and type:

reboot recovery

If you don't want to void your warranty please use the dirty santa by following this threat:
https://forum.xda-developers.com/v20/development/ls997vs995h910-dirtysanta-bootloader-t3519410
In this threat you will unlock you boot loader n flashing recovery. Right after you've done step 3 and your phone boot up you can wait (I dont recommend you to wait for you phone boot up, mine have screen static after that so just following these step to enter TWRP we will fix it later):
1. unplug the cable right after the logo boot up
2. remove the battery.
3. boot your phone up while holding BOTH vol down and power key.
4. Briefly release the power key right after you saw the LG logo and press it back again.
5. untill your phone boot up use vol key and power key to select yes on both screen.
6. wait for you phone reboot and now you in TWRP.
7. Select cancel if the phone ask you for password and swipe to right to allow modifications.
Flashing modem, fix screen static and other.
Now put these files in your SD card or your internal storage with mount option in TWRP (Mount=> enable MTP): Modem.img, SuperSU or Magisk, kernel and boot2.img (in adb folder).
In TWRP:
1. Tap on "wipe" => format data => type "yes"
2. Go back to home menu then select “Reboot” then “Recovery”.
3. Once rebooted, swipe to right again.
4. Tap on “Install”.
5. Choose your microSD card or internal storage depend on where you copy those files.
6. Tap on "Install Image" and select "modem.img"
7. Select "modem" and Swipe to flash.
If you use dirtysanta method you need to flash "boot2.img" to fix the screen static. Similar to flashing "modem.img" but you select "boot" before swipe to flash.
8. Go back to home menu then select “Reboot” then “System”.
Wait for your phone boot up and the issue should be fixed.
Additional things
For more advance you can flash SuperSU or Magisk if you want to root you phone for more benefit.
Flashing kernel to fix your screen retention, screen static and more ( this won't cause SafetyNet failure that mean you can use android pay and banking app).
mk2000 kernel features:
Linux 3.18.85
KCAL - Screen panel control.
ElementalX and Zzmoove CPU governors.
Modules signed and secure, as in stock rom.
Disable software CRC checking of SD Card - More performance.
Fix by emdroidle for eng-bootloader (US996Santa, H990 & H910).
CRC32 and CHACHA20 HW ACC, CRNG based on CHACHA20.
Static screen fixed (US996Santa, H990 & H910).
Many patches that improves or fixes things.
Maple I/O scheduler.
LZ4 compression.
RCTD removed.
You need to flash kernel right after SuperSU/Magisk or before you reboot to system.
Update:
in case you want to upgrade to the lastest OTA you can follow this threat:
https://forum.xda-developers.com/v20/development/rom-us99610k-stock-rom-twrp-flashable-t3691784
And you need to reflash the "modem.img".
My thanks to:
@askermk2000 for his kernel.
@jcadduono, @me2151 for rooting guide.

sir is this only applicable for US996? i have my v20 H91010I same issue after updates no signal and radio. i was waiting for threads like this but hopefully this will work for other variant

 

[ttnduy]

sir is this only applicable for US996? i have my v20 H91010I same issue after updates no signal and radio. i was waiting for threads like this but hopefully this will work for other variant

Idk if this gonna work with H910 but you can try. If you still in warranty than you better turn it in. Btw you may need the modem file from other working H910.

 

[phamanhvu01]

You saved my ass and my US996, with your guide. Thanks!

 

[einsteino]

I have this same issue on my LS997, but as you may know there is no stock kdz for LS997(LG V20 SPRINT). If i were to flash the US996 Kdz to my LS997 via LGUP(yes it would boot fine) and then follow your steps ie flash US996 modem to my LS997 after hitting it with US996 kdz, would that get my radio working?

 

[ttnduy]

I have this same issue on my LS997, but as you may know there is no stock kdz for LS997(LG V20 SPRINT). If i were to flash the US996 Kdz to my LS997 via LGUP(yes it would boot fine) and then follow your steps ie flash US996 modem to my LS997 after hitting it with US996 kdz, would that get my radio working?

Maybe, since i only have us996 so i couldn't tell you if that gonna work or not. But i think, it worth to try. Btw be carefully with the ARB.

 

[einsteino]

Maybe, since i only have us996 so i couldn't tell you if that gonna work or not. But i think, it worth to try. Btw be carefully with the ARB.

Thanks for your reply. I was able to fix it by flashing the ls997 ZV6 firmware zip that someone posted on one of the threads

 

[zee789]

First of all, thank you for this guide.. You were savior of my LG V20 US996 to turn back with signal . But even my signal is exist, I cannot connect to internet. I stay in Indonesia. I already changed every modem (around 5 times I suppose..) but stilL can't connect to internet. Do you have any suggestion?

Thank you

 

[-MW-]

US99610f not in Google Drive Link

Hello ttnduy,

I am following your guide. I was just wondering if you have US99610f for (Unlocked) version. The download at lg-firmwares[dot]com/lg-us996-firmwares/firmwares/ is pain fully slow.

Thanks mate

MW

 

[ttnduy]

First of all, thank you for this guide.. You were savior of my LG V20 US996 to turn back with signal . But even my signal is exist, I cannot connect to internet. I stay in Indonesia. I already changed every modem (around 5 times I suppose..) but stilL can't connect to internet. Do you have any suggestion?

Thank you

Maybe the different in mobile broadband or something, do you try reflash the modem file or ROM ?

 

[ttnduy]

Hello ttnduy,

I am following your guide. I was just wondering if you have US99610f for (Unlocked) version. The download at lg-firmwares[dot]com/lg-us996-firmwares/firmwares/ is pain fully slow.

Thanks mate

MW

I have updated the US99610f kdz file for the unlocked version. Hope this gonna help.

 

[kmn5]

Hi all,
on my LG-US996
when I tried to run the bootloader from the LG page
I get the following error
"Unfortunately, your device(United States, (US CELLULAR_TULSA(USA)) )does not support unlocking the bootloader."
What are my options now? How else can I get the on board radio/modem working again?

My phone stopped working after the update from the LG Bridge. (I would have been better off not doing any update)

 

[stinka318]

You have to be careful what kdz you flash on us996 I have found if you flash the wrong kdz it will not work properly and can be a hassle to get it back.....

 

[crs77]

You have saved my ass! I thanked you, and rated your post as excellent, but i feel the need to also post a thank you! Merry Christmas, Happy Holidays and may you have a Happy New Year!

 

[Areechen]

Help request..

Recently i bought v20 us996 unlocked us cellular.
And it's automatically updated to us99610n.
The signal was lost after that.

What I've done after following this thread instruction:
1. Downgrade to us99610f via patched LGUP. Success.
2. Unlock bootloader via LG developer web. Failed.
I inputted imei & device ID 64 digits. But it's unmatch.
What's wrong with my step?
I'm using adb & got device ID.

My v20 condition now is most basic apps force closed.
I would like to unlock via dirtysanta, but I'm kind of confused. This is my first time using adb.

I hope to get some help in here ???
FYI I'm in Indonesia.
Thanks.

 

[ttnduy]

Hi all,
on my LG-US996
when I tried to run the bootloader from the LG page
I get the following error
"Unfortunately, your device(United States, (US CELLULAR_TULSA(USA)) )does not support unlocking the bootloader."
What are my options now? How else can I get the on board radio/modem working again?

My phone stopped working after the update from the LG Bridge. (I would have been better off not doing any update)

Recently i bought v20 us996 unlocked us cellular.
And it's automatically updated to us99610n.
The signal was lost after that.

What I've done after following this thread instruction:
1. Downgrade to us99610f via patched LGUP. Success.
2. Unlock bootloader via LG developer web. Failed.
I inputted imei & device ID 64 digits. But it's unmatch.
What's wrong with my step?
I'm using adb & got device ID.

My v20 condition now is most basic apps force closed.
I would like to unlock via dirtysanta, but I'm kind of confused. This is my first time using adb.

I hope to get some help in here
FYI I'm in Indonesia.
Thanks.

unlock bootloader via LG web can be use with US996 UNLOCKED Version only, in your case US CELLULAR, you should follow the DirtySanta method to unlock your bootloader and the rest still be the same with the unlocked version.
Hope this help.

 

[ttnduy]

You have saved my ass! I thanked you, and rated your post as excellent, but i feel the need to also post a thank you! Merry Christmas, Happy Holidays and may you have a Happy New Year!

Thank you. I'm glad this help and Happy New Year.

 

[Areechen]

unlock bootloader via LG web can be use with US996 UNLOCKED Version only, in your case US CELLULAR, you should follow the DirtySanta method to unlock your bootloader and the rest still be the same with the unlocked version.
Hope this help.

Hi ttnduy,

OK I'll try it. I'll post if i found some problem.
Thanks for your response.