[GUIDE][No Network or No 3g/LTE]ACTIVATE 2G 3G & 4G on LG G3

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Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
USE AT YOUR OWN RISK


This guide is intended for those individuals who can not use 3g or LTE but 2g works perfectly for them or they have lost their network and flashing different radios does not help

To check if you have this problem, go to settings>more>Mobile Network>Manual Search

You should have GSM / WDCMA/LTE or others depending on your network from all networks in your area.


What do you need :

*Drivers installed
*USB debugging (enable by going into settings>software information> tap on build number 10 times and developer options will appear in settings at the end. Enable USB debugging from there)
*ROOT
*QPST (QPST DOWNLOAD) LINK2

*EFS BACKUP TOOL (EFS BACKUP THREAD)
* Device specific backup of QCN (FIND IT YOURSELF AS IT WILL CHANGE YOUR IMEI TOO)
*DIAG MODE ENABLED

This is how to enable diag mode via platform tools using ADB on LG devices

Code:
 adb shell
 su
 echo 1 > /sys/devices/platform/lg_diag_cmd/diag_enable
 setprop sys.usb.config acm,diag,mtp,adb

It is preferred to clear these partitions by using these commands and restart your phone before flashing qcn files. I wiped wrong partitions (tz)using these commands and I got a HARD BRICK. YES A HARD BRICK so be very careful

Code:
dd if=/dev/zero of=/dev/block/mmcblk0p21
dd if=/dev/zero of=/dev/block/mmcblk0p22
dd if=/dev/zero of=/dev/block/mmcblk0p24

Restore by, where XX is the number and YY name of partition
Code:
dd if=/dev/block/[B]mmcblk0pXX/B] of=/sdcard/[B]YY[/B].epb
Example
Code:
dd if=/dev/block/mmcblk0p9 of=/sdcard/system.img

However, you can go ahead and clear these partitions only if you had a previous backup by blocks like EFS FILE EXPLORER. modemst1, modemst2, fsg, fsc,dbi, ddr, pad
Check which partition corresponds to which block by
Code:
ls -al /dev/block/platform/msm_sdcc.1/by-name

Once your device is connected, drivers and software installed,

You may need to first go to QPSTConfig which is located at QPST > Bin. There you will need to select port which will show your snapdragon model.

Go to QPST > Bin> QPSTServer.exe

1.A globe would appear in taskbar. Click on it and select software download.

2.Select port of your diagnostic mode in restore tab of software download

3. Once in software download, backup your current QCN (just as a backup to be safe)

4. Restore the QCN you found from google. Make sure it is device specific (use d850 QCN for d850 only)

5. Device would restart and automatically start to search 3g and LTE signals

Good luck


My original QCN was 31kb which clearly showed lost of data but the one that worked was about 500kb.


Lastly there are other methods to restore as well which I will look into so I can post in more details so your IMEI does not change.

Edit: You can do it by changing NV VALUE of 457 to your default value to keep your imei number as well


I will try to backup my radio partitions if someone needs help to fix their network issues or other possible solutions that could be found

HOW TO REVERT YOUR IMEI BACK TO ORIGINAL

1. Download EFS Professional. FROM HERE
2. Make sure you are rooted and busy box working.
3. Use commands as stated above to boot your phone in DIAG mode. This can be done anytime after connecting your phone to the PC.
4. Go to Qualcomm NV tools
5. Choose right port and connect.
6 Go to Secure Ops. tab and change imei from there. Make sure you have a full backup.

If this fails, you can use QXDM and go to NV tools and manually change your IMEI back to its real value. You will need to go to NV Values tab and then on side tab choose Security from All, and then change IMEI number to your real one. You can check details how to change values in QXDM in futher reading below. Samsung S5 thread explains it really well.


If you still are not sure, you can use QPST software. Go to NV manager and find your IMEI number after connecting the phone in diag mode. Usually it is 550 or 457 value.

Use Imei converter from attached files below and insert the converted values.

Good Luck

THREADS TO LOOK FOR FURTHER READ
Unlock Bands and how to boot into Diag mode All credits to @olokos for his guide
Unlock LTE bands and go into diag mode
All credits to @fffft for his guide
FOR BEST RESULTS WHICH I FOUND HAD MORE SUCCESS WITH


1. First understand the problem fully here
2. Flash a working qcn to your device
3. Wipe partitions as commands given above
4. restart
5. Flash a working qcn on it again. Preferably the same one
6. Check if you get signals now, if not then do a factory reset and see

Profit ? No

7. Install TOT stock 4.4.2 or Lollipop (I had more success with Lollipop)
8. Install a qcn from another device. Just to break all your signals (do at your own risk) I flashed a D855 qcn to my d850
9. Restart and wipe partitions
10. Reflashed working Qcn again

Profit ? No

It did not work till here so I moved to stock lollipop by flashing zip in TWRP. If you have TOT method, that is better.

So I went to flash Lollipop stock with modem of D850. (because it was zip and did not include modem. In TOT/ KDZ all partitions are flashed so you do not need to flash modem separately) So i wiped partitions again and then I flashed QCN using cracked version of Z3x Lg Tools twice. (same qcn but two times) and then restarted.
It restored everything back. Everything came to work fine

Z3X Cracked Download here



WHAT YOU CAN DO TO HELP OTHERS
(needs root and busybox installed)

I suggest you make a backup of your EFS via TWRP & EFS TOOL before tinkering with hidden menu or anything at all. If you do these steps correctly, you do not risk of any damage to your device.

Download EFS Tool from here
http://xdaforums.com/atta...6&d=1419867628

Main thread of it
http://xdaforums.com/gala...546?styleid=18

1. go in backup tab
2. select all partitions
3. Select 3 partitions

backup modem, modemst1 and modemst2 and upload it for me so I can try to restore the settings to see if that works.

MAKE SURE YOU WRITE YOUR DEVICE MODEL when attaching those mentioned partitions AND DOUBLE CHECK IT AS FLASHING WRONG radios can permanently damage your device.



DEVICE I FIXED WAS D850 ATT Variant and had success with other variants as well


UPDATE
I have attached a D855 qcn with null imei. You will need to change your imei yourself which you can find by removing your battery. Make sure to make a backup before trying anything and I WILL BE NOT RESPONSIBLE


HISTORY --- JUST TO COMPARE IF YOU HAVE SIMILAR PROBLEM
hi there,
I am working to fix the problem many users have faced and therefore trying to find possible solutions. I need some partition images from you guys if you can provide me so I can try to fix the issues.

THE PROBLEM AND HOW IT STARTED :


I have got a D850 which I am using in Europe. The problem started when I inserted an LTE enabled sim and went to hidden menu to change my mode to LTE only, I was on Fulmics Rom 2.7 Lollipop at that time. Before that, ii network search, I could see all WCDMA, GSM and LTE bands used by different providers by manual search.

After changing it to LTE only, I could not see any signal bars and it started searching. As I was in an area where LTE signals were weak, so I thought maybe I need to change back to GSM/WCDMA/LTE from settings. Signals returned to normal but only to gsm. LTE and 3G were lost as searching for networks did not help at all.

I tinkered with hidden menu and selected GSM/WCDMA/LTE ( 3845#*850# ) from hidden menu

and

used this ( *#*#4636#*#* ) to change back to GSM/WCDMA/LTE from another hidden menu.

It didnot help.

I flashed different modems (one from kitkat and two versions from Lollipop) but that didnot help either.

I reverted back to KITKAT using TOT method and the WCDMA and LTE were lost forever when i tried to search manually. So I made an EFS backup and started tinkering with hidden method.

Actually I was not expecting that the values would be affected by using the hidden menu to fix my network to LTE only.

I then backup my EFS and tinkered with hidden menu and i was successful in bringing back LTE, however, I was stuck with no 3g.

Using build prop editor, I changed my operator from ATT to OPEN (as ATT does not show default selection menu for GSM/WCDMA/LTE in settings/ both hidden menus) which enabled the option by which I could changed my preferred network type.

In hidden menu, I just enabled VoLTE in LTE > Modem Settings > VoLTE On which brought back LTE.

Next I installed QPST & QXDM to check my NV values and IMEI.

All of those were perfectly fine. No problem at all.


Strangely all the NV values are right. I restored my EFS to old state where I didnot have LTE or 3g. The LTE was gone again.

I again enabled VoLTE from hidden menu and LTE came back.


See attached image for reference.

POSSIBLE SOLUTION :

I think the problem lies in ATT settings as it has preset operator settings which changes from GSM to WCDMA to LTE depending on its values.
Once I selected LTE only, I disabled the WCDMA and somehow broke the AT&T preset settings as you can not change preferred network from settings like D855 or other models. Somehow we need to re-enable these and one possible way would be to flash modemst 1 and modemst 2 from backup.


Please help me find the possible solution

PS : For all those who are wondering if i tried other sims and tried to use 4g/3g on another device. Yes i did and the problem is only in D850
I also made a proper working APN. Plus I check which network I am on by using *#*#4636#*#*

dd if=/home/med/Desktop/tz.img of=/dev/sdb6

ANY SUGGESTIONS ?[/U][/COLOR][/B] @hyelton


People who can not flash QCN need to break their Lg lock which is done by flashing someone else Twrp backup of same device on your phone. After this, you will be able to flash QCN without issues
 

Attachments

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  • LG_D855.rar
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Last edited:

hyelton

Recognized Contributor
May 26, 2010
13,958
6,233
31
Wilmington
hi there,
I am working to fix the problem many users have faced and therefore trying to find possible solutions. I need some partition images from you guys if you can provide me so I can try to fix the issues.

THE PROBLEM AND HOW IT STARTED :


I have got a D850 which I am using in Europe. The problem started when I inserted an LTE enabled sim and went to hidden menu to change my mode to LTE only, I was on Fulmics Rom 2.7 Lollipop at that time. Before that, ii network search, I could see all WCDMA, GSM and LTE bands used by different providers by manual search.

After changing it to LTE only, I could not see any signal bars and it started searching. As I was in an area where LTE signals were weak, so I thought maybe I need to change back to GSM/WCDMA/LTE from settings. Signals returned to normal but only to gsm. LTE and 3G were lost as searching for networks did not help at all.

I tinkered with hidden menu and selected GSM/WCDMA/LTE ( 3845#*850# ) from hidden menu

and

used this ( *#*#4636#*#* ) to change back to GSM/WCDMA/LTE from another hidden menu.

It didnot help.

I flashed different modems (one from kitkat and two versions from Lollipop) but that didnot help either.

I reverted back to KITKAT using TOT method and the WCDMA and LTE were lost forever when i tried to search manually. So I made an EFS backup and started tinkering with hidden method.

Actually I was not expecting that the values would be affected by using the hidden menu to fix my network to LTE only.

I then backup my EFS and tinkered with hidden menu and i was successful in bringing back LTE, however, I was stuck with no 3g.

Using build prop editor, I changed my operator from ATT to OPEN (as ATT does not show default selection menu for GSM/WCDMA/LTE in settings/ both hidden menus) which enabled the option by which I could changed my preferred network type.

In hidden menu, I just enabled VoLTE in LTE > Modem Settings > VoLTE On which brought back LTE.

Next I installed QPST & QXDM to check my NV values and IMEI.

All of those were perfectly fine. No problem at all.


Strangely all the NV values are right. I restored my EFS to old state where I didnot have LTE or 3g. The LTE was gone again.

I again enabled VoLTE from hidden menu and LTE came back.


REQUEST , WHAT YOU CAN DO TO HELP
(needs root and busybox installed)

I suggest you make a backup of your EFS via TWRP & EFS TOOL before tinkering with hidden menu or anything at all. If you do these steps correctly, you do not risk of any damage to your device.

Download EFS Tool from here
http://xdaforums.com/atta...6&d=1419867628

Main thread of it
http://xdaforums.com/gala...546?styleid=18

1. go in backup tab
2. select all partitions
3. Select 3 partitions

backup modem, modemst1 and modemst2 and upload it for me so I can try to restore the settings to see if that works.

See attached image for reference.

POSSIBLE SOLUTION :

I think the problem lies in ATT settings as it has preset operator settings which changes from GSM to WCDMA to LTE depending on its values.
Once I selected LTE only, I disabled the WCDMA and somehow broke the AT&T preset settings as you can not change preferred network from settings like D855 or other models. Somehow we need to re-enable these and one possible way would be to flash modemst 1 and modemst 2 from backup.


Please help me find the possible solution

PS : For all those who are wondering if i tried other sims and tried to use 4g/3g on another device. Yes i did and the problem is only in D850
I also made a proper working APN. Plus I check which network I am on by using *#*#4636#*#*



ANY SUGGESTIONS ?[/U][/COLOR][/B] @hyelton

Maybe the D850 does NOT have the bands that the carrier your trying to use it on? Flashing another modem wont enable bands the hardware does not have.
 

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
USE AT YOUR OWN RISK


This guide is intended for those individuals who can not use 3g or LTE but 2g works perfectly for them or they have lost their network and flashing different radios does not help

What do you need :

*Drivers installed
*USB debugging
*QPST (google it or google UNLOCK ALL BANDS QUALCOMM XDA and download from one of the forum there as it is banned)
*EFS BACKUP TOOL (available at xda or find link in history below)
* Device specific backup of QCN (FIND IT YOURSELF AS IT WILL CHANGE YOUR IMEI TOO)
*DIAG MODE ENABLED
This is how to enable diag mode via platform tools using ADB on LG devices
1) adb shell
2) su
3) echo 1 > /sys/devices/platform/lg_diag_cmd/diag_enable
4) setprop sys.usb.config acm,diag,mtp,adb

Once your device is connected, proper drivers and software installed,

Go to QPST > Bin> QPSTServer.exe

1.A globe would appear in taskbar. Click on it and select software download.

2.Select port of your diagnostic mode in restore tab of software download

3. Once in software download, backup your current QCN (just as a backup to be safe)

4. Restore the QCN you found from google. Make sure it is device specific (use d850 QCN for d850 only)

5. Device would restart and automatically start to search 3g and LTE signals

Good luck



My original QCN was 31kb which clearly showed lost of data but the one that worked was about 500kb.


Lastly there are other methods to restore as well which I will look into so I can post in more details so your IMEI does not change


I will try to backup my radio partitions if someone needs help to fix their network issues or other possible solutions that could be found



REQUEST , WHAT YOU CAN DO TO HELP
(needs root and busybox installed)

I suggest you make a backup of your EFS via TWRP & EFS TOOL before tinkering with hidden menu or anything at all. If you do these steps correctly, you do not risk of any damage to your device.

Download EFS Tool from here
http://xdaforums.com/atta...6&d=1419867628

Main thread of it
http://xdaforums.com/gala...546?styleid=18

1. go in backup tab
2. select all partitions
3. Select 3 partitions

backup modem, modemst1 and modemst2 and upload it for me so I can try to restore the settings to see if that works.

MAKE SURE YOU WRITE YOUR DEVICE MODEL when attaching those mentioned partitions AND DOUBLE CHECK IT AS FLASHING WRONG radios can permanently damage your device.



DEVICE I FIXED WAS D850 ATT Variant


HISTORY
hi there,
I am working to fix the problem many users have faced and therefore trying to find possible solutions. I need some partition images from you guys if you can provide me so I can try to fix the issues.

THE PROBLEM AND HOW IT STARTED :


I have got a D850 which I am using in Europe. The problem started when I inserted an LTE enabled sim and went to hidden menu to change my mode to LTE only, I was on Fulmics Rom 2.7 Lollipop at that time. Before that, ii network search, I could see all WCDMA, GSM and LTE bands used by different providers by manual search.

After changing it to LTE only, I could not see any signal bars and it started searching. As I was in an area where LTE signals were weak, so I thought maybe I need to change back to GSM/WCDMA/LTE from settings. Signals returned to normal but only to gsm. LTE and 3G were lost as searching for networks did not help at all.

I tinkered with hidden menu and selected GSM/WCDMA/LTE ( 3845#*850# ) from hidden menu

and

used this ( *#*#4636#*#* ) to change back to GSM/WCDMA/LTE from another hidden menu.

It didnot help.

I flashed different modems (one from kitkat and two versions from Lollipop) but that didnot help either.

I reverted back to KITKAT using TOT method and the WCDMA and LTE were lost forever when i tried to search manually. So I made an EFS backup and started tinkering with hidden method.

Actually I was not expecting that the values would be affected by using the hidden menu to fix my network to LTE only.

I then backup my EFS and tinkered with hidden menu and i was successful in bringing back LTE, however, I was stuck with no 3g.

Using build prop editor, I changed my operator from ATT to OPEN (as ATT does not show default selection menu for GSM/WCDMA/LTE in settings/ both hidden menus) which enabled the option by which I could changed my preferred network type.

In hidden menu, I just enabled VoLTE in LTE > Modem Settings > VoLTE On which brought back LTE.

Next I installed QPST & QXDM to check my NV values and IMEI.

All of those were perfectly fine. No problem at all.


Strangely all the NV values are right. I restored my EFS to old state where I didnot have LTE or 3g. The LTE was gone again.

I again enabled VoLTE from hidden menu and LTE came back.


See attached image for reference.

POSSIBLE SOLUTION :

I think the problem lies in ATT settings as it has preset operator settings which changes from GSM to WCDMA to LTE depending on its values.
Once I selected LTE only, I disabled the WCDMA and somehow broke the AT&T preset settings as you can not change preferred network from settings like D855 or other models. Somehow we need to re-enable these and one possible way would be to flash modemst 1 and modemst 2 from backup.


Please help me find the possible solution

PS : For all those who are wondering if i tried other sims and tried to use 4g/3g on another device. Yes i did and the problem is only in D850
I also made a proper working APN. Plus I check which network I am on by using *#*#4636#*#*



ANY SUGGESTIONS ?[/U][/COLOR][/B] @hyelton
from where did you got the qcn file
 

Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
from where did you got the qcn file

Google depending on your device model.

D850 qcn

D855 qcn download

Or something on the lines of above

I had two at&t g3. (Both lost their qcn) , one d855 and now I'm using third d850. ( I almost lost qcn on this one too)
I realise that qcn is easily lost on d850 model as even rooting via kingroot can simply damage qcn.

I had to sell all others. Previous models qcn didnt enable 4g for me , however, i flashed these to older device and 4g started to work. And i flashed older qcn to this device and 4g stopped working.

So make sure you find a qcn which enables 4g with 3g n 2g.

I would suggest go to a tech guy in your area who works with unlocking phones and they usually use some kind of boxes to flash qcn.
Another way could be you request a friend whose 4g is working to make a backup and share it with you.

Lastly, find it online and flash it yourself.

You can also request NV values which wouldnt change imei (as long as you change the NV 457 value to 0)

Inbox me for more help.

Good luck
 
Last edited:
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adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
My imei is already 0 and the model is d850 and body is of d855
The problem is that I can't use 3g on it
2g and 4g works fine

Sent from my LG-D850 using Tapatalk
 

Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
My imei is already 0 and the model is d850 and body is of d855
The problem is that I can't use 3g on it
2g and 4g works fine

Sent from my LG-D850 using Tapatalk

I came here out of curiosity. Next time quote me if you expect a reply.

What you need to do is flash a QCN. I can try to repair your imei number and send you back.

What I will need is your imei number(remove your battery and see under it), model number and your qcn file. Make sure you inbox me these details and I will try to repair it for you.

Good Luck
 

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
I came here out of curiosity. Next time quote me if you expect a reply.

What you need to do is flash a QCN. I can try to repair your imei number and send you back.

What I will need is your imei number(remove your battery and see under it), model number and your qcn file. Make sure you inbox me these details and I will try to repair it for you.

Good Luck
As I told you that the body of the cell is from d855 and the sticker on the back is also false one with the imei of a d855

Sent from my LG-D850 using Tapatalk
 

Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
As I told you that the body of the cell is from d855 and the sticker on the back is also false one with the imei of a d855

Sent from my LG-D850 using Tapatalk

I can provide you with a qcn for device d850 but make sure you backup your own. Tell me if you would need it.

Also, the best thing would be that you send me your qcn and i try to repair it and send it to you back,

But i think the best thing could be to provide you with NV values. let me see if i can work something out.

QCN for d850
https://www.sendspace.com/file/ak2hkl
 
Last edited:

Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
Can you confirm that 2g,3g and 4g is working with that qcn
And a question for safety that what can happen at most if something goes wrong

Sent from my LG-D850 using Tapatalk

MAKE A BACKUP OF YOUR QCN. either using QPST or using TWRP (TWRP from xda as it can also backup EFS)

I flashed many and i had none problems. As long as you do have a backup to go back to. There is no problem.

PS : Share your qcn and maybe I can try to repair it. I got NV values from my device.

If your friend has the same device. Grab qcn from him too and we can work something out as well
 
Last edited:

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
MAKE A BACKUP OF YOUR QCN. either using QPST or using TWRP (TWRP from xda as it can also backup EFS)

I flashed many and i had none problems. As long as you do have a backup to go back to. There is no problem.

PS : Share your qcn and maybe I can try to repair it. I got NV values from my device.

If your friend has the same device. Grab qcn from him too and we can work something out as well
I already have a backup of efs I made by twrp
Is it all I've to do?

Sent from my LG-D850 using Tapatalk
 

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
Although it is enough but i will go ahead and make a backup of qcn using qpst.
I'm uploading my efs to Dropbox, I'll give you the link than
Can I just restore the efs files if you can provide me coz I don't want to mess with qpst
It's a bit difficult to me as I'm just a noob

Sent from my LG-D850 using Tapatalk
 

pjl3dm

Senior Member
Nov 21, 2010
61
15
Google depending on your device model.

D850 qcn

D855 qcn download

Or something on the lines of above

I had two at&t g3. (Both lost their qcn) , one d855 and now I'm using third d850. ( I almost lost qcn on this one too)
I realise that qcn is easily lost on d850 model as even rooting via kingroot can simply damage qcn.

I had to sell all others. Previous models qcn didnt enable 4g for me , however, i flashed these to older device and 4g started to work. And i flashed older qcn to this device and 4g stopped working.

So make sure you find a qcn which enables 4g with 3g n 2g.

I would suggest go to a tech guy in your area who works with unlocking phones and they usually use some kind of boxes to flash qcn.
Another way could be you request a friend whose 4g is working to make a backup and share it with you.

Lastly, find it online and flash it yourself.

You can also request NV values which wouldnt change imei

Inbox me for more help.

PS : i have come up with severe viral conjuctivitis so i might not be able to help you till it clears up.

Good luck

Hi I have a D855 LG G3 and I have the same exact problem, my 2G works perfectly fine but I am no longer able to access LTE or 3g (signal shuts down when I switch to 3g or LTE mode, Service is disabled).
My IMEI is fine and is not lost... I can see it in About screen, I have tried installing different lollipop modems and even downgraded to Lollipop and Kitkat rom and even tried Cyanogenmod 12.1, I never had the signal back on.


Can you please share the LG D855 QCN? I have no idea where to get it, googling has not gotten me anywhere, I saw a SINGLE site where I could download it but it had a password.
 

Hnk1

Senior Member
Dec 23, 2012
1,466
1,550
Newcastle Upon Tyne
OnePlus 5
Moto G6
I'm uploading my efs to Dropbox, I'll give you the link than
Can I just restore the efs files if you can provide me coz I don't want to mess with qpst
It's a bit difficult to me as I'm just a noob

Sent from my LG-D850 using Tapatalk

Well, i will tell you step by step how to make a backup of QCN and how to flash QCN. It will be fine.
How did you manage to back it up ?

Mate you sent me EFS which means I need to use it on my device and then fix it and then send you.
Can you manage a QCN ?

It is very easy. Let me get back to you by night but I WILL PREFER QCN

Hi I have a D855 LG G3 and I have the same exact problem, my 2G works perfectly fine but I am no longer able to access LTE or 3g (signal shuts down when I switch to 3g or LTE mode, Service is disabled).
My IMEI is fine and is not lost... I can see it in About screen, I have tried installing different lollipop modems and even downgraded to Lollipop and Kitkat rom and even tried Cyanogenmod 12.1, I never had the signal back on.


Can you please share the LG D855 QCN? I have no idea where to get it, googling has not gotten me anywhere, I saw a SINGLE site where I could download it but it had a password.

Check your inbox. Tell me the result. And always remember : BACK UP BACK UP BACK UP FIRST
 
Last edited:

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
Hi I have a D855 LG G3 and I have the same exact problem, my 2G works perfectly fine but I am no longer able to access LTE or 3g (signal shuts down when I switch to 3g or LTE mode, Service is disabled).
My IMEI is fine and is not lost... I can see it in About screen, I have tried installing different lollipop modems and even downgraded to Lollipop and Kitkat rom and even tried Cyanogenmod 12.1, I never had the signal back on.


Can you please share the LG D855 QCN? I have no idea where to get it, googling has not gotten me anywhere, I saw a SINGLE site where I could download it but it had a password.
Did you checked your hangouts

Sent from my LG-D850 using Tapatalk
 

adil.ali.503

Senior Member
Oct 14, 2013
96
22
27
Lahore
here you go.

Just run restore via twrp and your imei should be fixed. Good luck

I will appreciate if you tell me if it worked for you!
Sorry to say it doesn't work
Imei is still 0 and I can't get any 3g signals
I think its the problem with the frequency band
Thanks for your help ?

Sent from my LG-D850 using Tapatalk
 

ItBankRock

Senior Member
Jan 14, 2012
530
236
Lipa City
I'm still getting 4G LTE signals but it seems that I cannot get any data at all (any website can't load). Will this help solve it?
 

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    USE AT YOUR OWN RISK


    This guide is intended for those individuals who can not use 3g or LTE but 2g works perfectly for them or they have lost their network and flashing different radios does not help

    To check if you have this problem, go to settings>more>Mobile Network>Manual Search

    You should have GSM / WDCMA/LTE or others depending on your network from all networks in your area.


    What do you need :

    *Drivers installed
    *USB debugging (enable by going into settings>software information> tap on build number 10 times and developer options will appear in settings at the end. Enable USB debugging from there)
    *ROOT
    *QPST (QPST DOWNLOAD) LINK2

    *EFS BACKUP TOOL (EFS BACKUP THREAD)
    * Device specific backup of QCN (FIND IT YOURSELF AS IT WILL CHANGE YOUR IMEI TOO)
    *DIAG MODE ENABLED

    This is how to enable diag mode via platform tools using ADB on LG devices

    Code:
     adb shell
     su
     echo 1 > /sys/devices/platform/lg_diag_cmd/diag_enable
     setprop sys.usb.config acm,diag,mtp,adb

    It is preferred to clear these partitions by using these commands and restart your phone before flashing qcn files. I wiped wrong partitions (tz)using these commands and I got a HARD BRICK. YES A HARD BRICK so be very careful

    Code:
    dd if=/dev/zero of=/dev/block/mmcblk0p21
    dd if=/dev/zero of=/dev/block/mmcblk0p22
    dd if=/dev/zero of=/dev/block/mmcblk0p24

    Restore by, where XX is the number and YY name of partition
    Code:
    dd if=/dev/block/[B]mmcblk0pXX/B] of=/sdcard/[B]YY[/B].epb
    Example
    Code:
    dd if=/dev/block/mmcblk0p9 of=/sdcard/system.img

    However, you can go ahead and clear these partitions only if you had a previous backup by blocks like EFS FILE EXPLORER. modemst1, modemst2, fsg, fsc,dbi, ddr, pad
    Check which partition corresponds to which block by
    Code:
    ls -al /dev/block/platform/msm_sdcc.1/by-name

    Once your device is connected, drivers and software installed,

    You may need to first go to QPSTConfig which is located at QPST > Bin. There you will need to select port which will show your snapdragon model.

    Go to QPST > Bin> QPSTServer.exe

    1.A globe would appear in taskbar. Click on it and select software download.

    2.Select port of your diagnostic mode in restore tab of software download

    3. Once in software download, backup your current QCN (just as a backup to be safe)

    4. Restore the QCN you found from google. Make sure it is device specific (use d850 QCN for d850 only)

    5. Device would restart and automatically start to search 3g and LTE signals

    Good luck


    My original QCN was 31kb which clearly showed lost of data but the one that worked was about 500kb.


    Lastly there are other methods to restore as well which I will look into so I can post in more details so your IMEI does not change.

    Edit: You can do it by changing NV VALUE of 457 to your default value to keep your imei number as well


    I will try to backup my radio partitions if someone needs help to fix their network issues or other possible solutions that could be found

    HOW TO REVERT YOUR IMEI BACK TO ORIGINAL

    1. Download EFS Professional. FROM HERE
    2. Make sure you are rooted and busy box working.
    3. Use commands as stated above to boot your phone in DIAG mode. This can be done anytime after connecting your phone to the PC.
    4. Go to Qualcomm NV tools
    5. Choose right port and connect.
    6 Go to Secure Ops. tab and change imei from there. Make sure you have a full backup.

    If this fails, you can use QXDM and go to NV tools and manually change your IMEI back to its real value. You will need to go to NV Values tab and then on side tab choose Security from All, and then change IMEI number to your real one. You can check details how to change values in QXDM in futher reading below. Samsung S5 thread explains it really well.


    If you still are not sure, you can use QPST software. Go to NV manager and find your IMEI number after connecting the phone in diag mode. Usually it is 550 or 457 value.

    Use Imei converter from attached files below and insert the converted values.

    Good Luck

    THREADS TO LOOK FOR FURTHER READ
    Unlock Bands and how to boot into Diag mode All credits to @olokos for his guide
    Unlock LTE bands and go into diag mode
    All credits to @fffft for his guide
    FOR BEST RESULTS WHICH I FOUND HAD MORE SUCCESS WITH


    1. First understand the problem fully here
    2. Flash a working qcn to your device
    3. Wipe partitions as commands given above
    4. restart
    5. Flash a working qcn on it again. Preferably the same one
    6. Check if you get signals now, if not then do a factory reset and see

    Profit ? No

    7. Install TOT stock 4.4.2 or Lollipop (I had more success with Lollipop)
    8. Install a qcn from another device. Just to break all your signals (do at your own risk) I flashed a D855 qcn to my d850
    9. Restart and wipe partitions
    10. Reflashed working Qcn again

    Profit ? No

    It did not work till here so I moved to stock lollipop by flashing zip in TWRP. If you have TOT method, that is better.

    So I went to flash Lollipop stock with modem of D850. (because it was zip and did not include modem. In TOT/ KDZ all partitions are flashed so you do not need to flash modem separately) So i wiped partitions again and then I flashed QCN using cracked version of Z3x Lg Tools twice. (same qcn but two times) and then restarted.
    It restored everything back. Everything came to work fine

    Z3X Cracked Download here



    WHAT YOU CAN DO TO HELP OTHERS
    (needs root and busybox installed)

    I suggest you make a backup of your EFS via TWRP & EFS TOOL before tinkering with hidden menu or anything at all. If you do these steps correctly, you do not risk of any damage to your device.

    Download EFS Tool from here
    http://xdaforums.com/atta...6&d=1419867628

    Main thread of it
    http://xdaforums.com/gala...546?styleid=18

    1. go in backup tab
    2. select all partitions
    3. Select 3 partitions

    backup modem, modemst1 and modemst2 and upload it for me so I can try to restore the settings to see if that works.

    MAKE SURE YOU WRITE YOUR DEVICE MODEL when attaching those mentioned partitions AND DOUBLE CHECK IT AS FLASHING WRONG radios can permanently damage your device.



    DEVICE I FIXED WAS D850 ATT Variant and had success with other variants as well


    UPDATE
    I have attached a D855 qcn with null imei. You will need to change your imei yourself which you can find by removing your battery. Make sure to make a backup before trying anything and I WILL BE NOT RESPONSIBLE


    HISTORY --- JUST TO COMPARE IF YOU HAVE SIMILAR PROBLEM
    hi there,
    I am working to fix the problem many users have faced and therefore trying to find possible solutions. I need some partition images from you guys if you can provide me so I can try to fix the issues.

    THE PROBLEM AND HOW IT STARTED :


    I have got a D850 which I am using in Europe. The problem started when I inserted an LTE enabled sim and went to hidden menu to change my mode to LTE only, I was on Fulmics Rom 2.7 Lollipop at that time. Before that, ii network search, I could see all WCDMA, GSM and LTE bands used by different providers by manual search.

    After changing it to LTE only, I could not see any signal bars and it started searching. As I was in an area where LTE signals were weak, so I thought maybe I need to change back to GSM/WCDMA/LTE from settings. Signals returned to normal but only to gsm. LTE and 3G were lost as searching for networks did not help at all.

    I tinkered with hidden menu and selected GSM/WCDMA/LTE ( 3845#*850# ) from hidden menu

    and

    used this ( *#*#4636#*#* ) to change back to GSM/WCDMA/LTE from another hidden menu.

    It didnot help.

    I flashed different modems (one from kitkat and two versions from Lollipop) but that didnot help either.

    I reverted back to KITKAT using TOT method and the WCDMA and LTE were lost forever when i tried to search manually. So I made an EFS backup and started tinkering with hidden method.

    Actually I was not expecting that the values would be affected by using the hidden menu to fix my network to LTE only.

    I then backup my EFS and tinkered with hidden menu and i was successful in bringing back LTE, however, I was stuck with no 3g.

    Using build prop editor, I changed my operator from ATT to OPEN (as ATT does not show default selection menu for GSM/WCDMA/LTE in settings/ both hidden menus) which enabled the option by which I could changed my preferred network type.

    In hidden menu, I just enabled VoLTE in LTE > Modem Settings > VoLTE On which brought back LTE.

    Next I installed QPST & QXDM to check my NV values and IMEI.

    All of those were perfectly fine. No problem at all.


    Strangely all the NV values are right. I restored my EFS to old state where I didnot have LTE or 3g. The LTE was gone again.

    I again enabled VoLTE from hidden menu and LTE came back.


    See attached image for reference.

    POSSIBLE SOLUTION :

    I think the problem lies in ATT settings as it has preset operator settings which changes from GSM to WCDMA to LTE depending on its values.
    Once I selected LTE only, I disabled the WCDMA and somehow broke the AT&T preset settings as you can not change preferred network from settings like D855 or other models. Somehow we need to re-enable these and one possible way would be to flash modemst 1 and modemst 2 from backup.


    Please help me find the possible solution

    PS : For all those who are wondering if i tried other sims and tried to use 4g/3g on another device. Yes i did and the problem is only in D850
    I also made a proper working APN. Plus I check which network I am on by using *#*#4636#*#*

    dd if=/home/med/Desktop/tz.img of=/dev/sdb6

    ANY SUGGESTIONS ?[/U][/COLOR][/B] @hyelton


    People who can not flash QCN need to break their Lg lock which is done by flashing someone else Twrp backup of same device on your phone. After this, you will be able to flash QCN without issues
    2
    Hi
    I literally just fixed it 5minutes ago was just on my way to post how i did it. The Magic thing was to delete the 3 Partitions from your first post. The moment i did that. every Program worked. QPST/EFS PROF/LG Z3X. The No Phone thing went away and everything worked flawlessly.

    I could flash the QCN and repair my Imei in minutes. I am sorry you did the work but for everyone else with the problem that your phone just isnt recognized, that could be the solution. I backed everything up beforehand with EFS Professional, and TWRP at least that worked before.

    I thank you alot for your help LTE and i guess 3g works? i unfortuanetly can not see if its 3g but Internet/calls work i tried :).

    that's great mate. I am glad everything worked out.
    Just for your reference and others, I am attaching the backup link here so everyone can benefit.

    https://mega.nz/#!zw8zHCpT!Oepsetz5KUuhS46aV7m5PdfBYruudHGEbG_TWCEX5Z0
    2
    Hi.

    Will gladly try your method when you provide step by step instructions.
    I am d855 btw so i dunno if it will work or not.

    Sent from my LG-D855 using Tapatalk

    Another thing mate, i will write you how to flash any QCN to your phone without any errors. Good Luck

    Try that before all the way from scratch.

    Download this from here :
    http://www.4shared.com/rar/EgDgbDMSba/Z3X_LG_2-3G_Tool_7_9_CRACKED.htm

    password is 123

    Then install and use loader to run the file. (i had to disable my antivirus)

    Afterwards, flash all the qcns i emailed you before..

    Another method is using QPST ServiceProg. Load from file and then write to phone. It may give errors so above method is far better
    Good luck
    2
    I haven't tried it yet as I'm unable to put my device in diagnostic mode
    Btw the efs files you gave me, I'm only able to get 2g signals with them


    Sent from my LG-D850 using Tapatalk

    Any progress ?

    Good night, is podible use this method in a LG G3 D851 .
    From already thank you very much

    Yes . But I hope you understand what this thread is about. You will need to find a QCN for a D851.

    Google is your friend!
    2
    Mate, can you please provide hex method with steps by ehich you repaired your IMEI. This will be very helpful to other users and i can add it in my original guide making it even more easier for rest of users.

    About your query, it seems that in one file 3g values are lost while in other 4g values are lost. What you can do is , flash a qcn with both LTE and 3G working and then change your imei to your original one.
    If you want to try, use QXDM and in NV TOOLS, select only LTE /3G and conpare 2 QCN. But it will be time consuming.

    If you can tell us how you edited imei using hex , i will change my IMEI to 0000000000000 and upload the file where you can flash my qcn and change your imei to original. But remember, it may take a bit as I am very busy lately. Good luck !



    Are you certain it is hardware related or qcn related.
    Try flashing a modem using twrp and see. If that doesnt help, reinstall your software using TOT method or KDZ.
    After that we can look into your QCN issue. Any more detail how it started will be helpful.

    Word of caution : I hope you backed up your previous QCN and I am not sure if a qcn of D855 will work on D855P.

    You will need device specific QCN

    Hi @Hnk1

    Sorry for the delay, bussy days...

    Here you have the method to replace IMEI, you just need to convert your IMEI with IMEI converter and do a search to find the right line for IMEI input as the guide is for LG G2 so the line number should vary.

    http://xdaforums.com/showpost.php?p=58171492&postcount=13

    I would like to use my email box to follow up since I currently pay more attention to email than forums due to workload, once we have results I can post back for the community. Ive my second D850 unit on the way so I can help you with 2 units on testings. Ive sent you my email on PM, feel free to email me your modified .qcn once you replace your original IMEI. I can test it here and let you know if solves the network issues we have with this model in our country.

    thanks for your coop! cheers.