The usual EFS backup method does not work for the N7105 as it has a Qualcomm chip to control the modem. You have to backup using a different method with the Qualcomm QPST tools. The process is easy to follow, but sadly, in your case it is too late of course.
See here:
http://forum.xda-developers.com/show....php?t=2008584
http://forum.xda-developers.com/show....php?t=1946915
Credit to:
lyriquidperfection
mitchelln
Please sticky this to some where more prominent
Mod Edit: Thread closed by @Darth . Pay per click links are not permitted on XDA.
4 Methods on How to Backup your IMEI
How to back up your IMEI
This is the most important things to do before flashing any rom or apps is to backup your imei.
After flashing ROMs or installing updates, it is possible that the phone will get an invalid IMEI or unknown baseband. Invalid IMEI would mean no mobile network connections.
Every mobile phone, GSM modem or device with a built-in phone / modem has a unique 15 digit IMEI number. I have 4 methods to back up your IMEI.
Method 1: Using mtkdroid tools
Requirements:
PC/LAPTOP
USB CABLE
ROOTED PHONE
DRIVER
mtkdroidtools.rar
Set your phone in USB debugging mode, then connect via USB cable.
Open mtkdroid tools
Click IMEI/NVRAM
Then navigate to Backup
This backup will save in your mtkdroid tools backup folder.
Method 2: Using MobileUncle Tools
Requirements:
ROOTED PHONE
mobileuncle.toolbox.apk
Open and install mobile uncle tools then navigate to backup imei. That's it!
Method 3: Using Rootexplorer
ROOTED PHONE
Rootexplorer.apk
Install and open Rootexplorer
Go to Root Folder
Navigate to data/nvram. Save this nvram folder in your sdcard.
Method 4: Using Carliv Touch Recovery 2.7 and 3.0
ROOTED PHONE
CTR 2.7 or 3.0
Flash this CTR 2.7/3.0 then go to recovery mode
Click carliv menu
Navigate to NVRAM
Choose Nvram backup
This nvram will save in clockworkmod/backup/nvram folder
Nowadays there's update in some custom recovery like twrp, philztouch and ctr that has nvram backup and restore menu. You can backup this nvram/imei by means of this custom recovery.
IF ALL THE ABOVE METHOD FAILS TELL ME ILL PROVIDE U A SOLID SOLUTION
XDA:DevDB Information
HOW TO BACKUP IMEI, ROM for all devices (see above for details)
Contributors
manhar2108
Source Code: REMOVED
ROM OS Version: 4.4.x KitKat
Version Information
Status: Testing
Created 2015-08-10
Last Updated 2015-08-10
Hello everyone, I would like to ask a simple question: the IMEI code of my P8 is corrupted and I need to restore it, where do I find the IMEI code to be restored. I made a Nandroid backup but inside there is no such directory "EFS" as in Samsung ..
Where is ??
many thanks
Giampiero
What happens if you restore the nandroid backup? Does the IMEI return?
If not, try the tip mentioned here: [Q]Repair IMEI - for Noobs
Xiaomi A3 efs backup and restore tool
to backup
EFS_persist_backup_g0dsend313
to restore
EFS_persist_restore_g0dsend313
download:
http://s4.picofile.com/file/8372556150/a3_efs_tool_by_g0dsend313.rar.html
pass:6969
XDA:DevDB Information
Xiaomi A3 efs backup and restore tool, Tool/Utility for the Xiaomi Mi A3
Contributors
mlm1102003, mlm1102003
Version Information
Status: Testing
Current Stable Version: 0.0.1
Created 2019-09-16
Last Updated 2019-09-16
Exactly what requirements do you need to be able to use this tool, I mean having root and twrp, modifications to the system risk the brick
Andres88z said:
Exactly what requirements do you need to be able to use this tool, I mean having root and twrp, modifications to the system risk the brick
Click to expand...
Click to collapse
Ideally you should have TWRP and Root. Frankly, you don't really need this tool, when TWRP will backup and restore EFS without any issue.
Worst case there is also the option of using QPST, there are also many tools available on Google play for backing up you partitions as long as you have root.
For example: Partitions Backup & Restore
Need qcn of efs backup
please you can post your EFS backup or QCN file from Mi A3, i`m without signal, but IMEI ok. i search on web but i cant find file.
i allready restore full stock ROM with fastboot method, but not fix the problem. After search on web about it, i finded on XdA and mi forum a case of Redmi Note 4 identical and the only method work is the restore with QCN file. please you can post the QCN file from Mi A3?
edson29jr said:
i allready restore full stock ROM with fastboot method, but not fix the problem. After search on web about it, i finded on XdA and mi forum a case of Redmi Note 4 identical and the only method work is the restore with QCN file. please you can post the QCN file from Mi A3?
Click to expand...
Click to collapse
https://androidfilehost.com/?fid=1899786940962589872
Hi
I am new to this forum and flashing android devices. Today i just managed to root my T-580 using newest TWRP and Magisk versions. The root-checker says its rooted, SafetyNet passes so eveything seems to be OK.
Before flashing any custom ROM i wanted to backup IMEI and NVRAM but without success.
I have tried different approaches:
1. minimal adb and fastboot - after entering commands i get illegal number of block size
2. platform tools - gives me no such file or directory mesage
3. mtkdroid root tools - device info is not read and backup is grayed out. what is strange that the available free space is succesfully read but not any other info.
Check the attachments for the screenshots.
Could anybody help me how can i backup IMEI and NVRAM data? Without this step i cannot proceed in flashing custom ROM.
Thank you
EDIT: is backing up EFS in TWRP the same procedure as backing up IMEI-NVRAM? so it might be enough to backup EFS to secure IMEI-NVRAM?