TO MINIMIZE THE CHANCE YOU LOSE YOUR IMEI, BE SURE AND ROOT/CWM USING THIS METHOD:
http://forum.xda-developers.com/showthread.php?t=1739426
AND ONLY FLASH ROMS INTENDED FOR USE ON YOUR MODEL
**UPDATED 7/16/12**
questions we are trying to answer:
- what versions of clockworkmod, if any, are prone to causing IMEI problems?
- what rooting methods, if any, are prone to causing IMEI problems?
- what ROMs are causing imei issues, and on which models? is the rooting/cwm method related?
- where is the IMEI stored on the phone, and most importantly
- is it possible to back it up, and restore it once corrupt?
RESTORING AN /EFS BACKUP DOES NOT APPEAR TO RESTORE AN IMEI AT THIS TIME.
TO BE SAFE, USE THIS GREAT SCRIPT BROUGHT TO YOU BY DROTHENBERGER AND SFERNANDEZ:
http://forum.xda-developers.com/showpost.php?p=28528532&postcount=38
You will need Cygwin (http://www.cygwin.com/) for the script.
Original post by sfernandez detailing the partitions: http://forum.xda-developers.com/showpost.php?p=28519596&postcount=39
IF YOU HAVE THIS ISSUE, PLEASE FILL THIS OUT AND POST. THANKS PINOYMUTT:
1. CARRIER VERSION:
(ATT, TMo, Sprint, Verizon, Bell, etc.)
2. ROOT METHOD:
Exact method you used to root, please link to the thread if possible
3. CWM INSTALLATION METHOD:
Again, please be specific. Examples include the ADB/DD method, flashing via ODIN, etc.
4. CWM VERSION:
Which CWM are you using -- the Sprint version or one of the Clockwork ones?
5. ROM(s) FLASHED:
Did you flash any ROMs after the above, and how did you flash it?
6. WHEN DID YOU FIRST NOTICE IMEI WAS GONE?:
It helps if you know which step may have caused the issue
7. OTHER NOTES:
RULES
1. Please READ THE ENTIRE THREAD BEFORE POSTING. There is way too much info in here for me to summarize.
2. ALWAYS READ THE THREAD BEFORE POSTING
3. If your phone is working properly and your IMEI is intact, and the method you used to root and install CWM has already been detailed by another member, WE DO NOT NEED TO KNOW IT ALSO WORKED FOR YOU. LET'S TRY AND KEEP THE THREAD CLUTTER DOWN
4. No arguing or bickering over stupid crap. Keep that to PMs.
5. READ THE THREAD BEFORE POSTING. THANK YOU.
original post:
If you have flashed a new ROM on your phone recently and have found difficulty or impossibility in getting cellular or data service, chances are you have corrupted or deleted the file that stores your IMEI. i'll try to answer a couple of common questions and detail methods i used, and why i think they failed
What is an IMEI?
your network identifies your phone by its IMEI. once i had "lost" mine, AT&T's network would not provide service to my device, even after getting a new sim card.
How can I check if mine is corrupted?
your IMEI is a 15-digit number under your battery. dialing *#06# should display the same number under your battery. if you get a different number or something like 0 / 00, you have corrupted your IMEI.
Changing the APNs
marginally effective at best. your phone is not registering on AT&T's network as a device it should send data to, so it doesn't matter what APN you use.
flashing to stock rom
did not work for me. probably because this probably doesn't effect the /efs partition, where the IMEI is stored.
use CWM / nandroid restore
from what I can tell, a standard backup does not back up the EFS partition. you need to use something like EFS pro to backup your /efs directory (where the IMEI is stored). restoring my phone to a previously stable and working save did not restore my IMEI
editing nv_data.bin
no one has been able to find this file on the SGH-i747
using a terminal / AT interface
it looks like the IMEI is encrypted and causes a stack overflow when you try to query it. notice how i can query my IMSI (edited) fine, but querying the IMEI causes a stack overflow. pic:
http://imgur.com/uZxZL
i probably tried a few more things i can't think of right now. moral of the story is... approach unstable roms with caution, and BACK UP YOUR EFS PARTITION!!!
anyone had any luck restoring a busted IMEI? :highfive:
EFS pro has not been updated to the correct partition for i747, so currently that method to backup/restore will not work.
Sent from my HTC One X using xda app-developers app
thanks for the info. will copying the entire /efs directory to my extsd using root explorer work?
It's not the EFS folder but the correct block partition in the dev folder.
Sent from my HTC One X using xda app-developers app
thanks for filling me in on this, still an android nub compared to you guys... did some digging and found this:
http://forum.xda-developers.com/archive/index.php/t-1689623.html
is that info still relevant/correct?
Not sure but cant hurt to do a full backup of all the blocks until someone can confirm that it's the same with the s4 version of the galaxy s3.
Sent from my HTC One X using xda app-developers app
can anyone confirm if using root explorer to backup /dev safely backs up your IMEI?
how can you do a backup of all the blocks on the phone?
I have not used this yet but you should read this thread and give it a try.
http://forum.xda-developers.com/showthread.php?t=1746665
nunyabiziz said:
I have not used this yet but you should read this thread and give it a try.
http://forum.xda-developers.com/showthread.php?t=1746665
Click to expand...
Click to collapse
thanks ill check it out
On my older captivate backing up the efs folder worked. Then if you loose the imei, restoring the folder or nvdata file fixed it. I'd backup the efs folder just in case.
Sent from my SAMSUNG-SGH-I747 using xda app-developers app
EFS Pro DO work with the S3. (I haven't try restoring my EFS, but backup went fine)
http://forum.xda-developers.com/showthread.php?t=1308546
What did you to loose IMEI? What ROM did you flash or what did you do wrong to cause this? Better to learn from somebody's else mistakes then your own.
When I had the problem on my Samsung Captivate, the EFS was wiped out when I converted from a CyangonMod rom to a standard Captivate based ROM. I didn't actually lock down what caused the issue (since I could easily fix it by restoring the nvdata.bin file - which I just kept handy on my external SD card and PC as well). I think it might have been when I ran a one-click ODIN to restore back to the RFS file system to install one of the custom Captivate ROMS. The only issue I ran into was the IMEI was different than what it should have been, but no usability issues at all. So moral of the story is, it's possible it can happen any time you flash a new ROM, backup your EFS folder and keep it in a safe place (I believe it's just the NVDATA.BIN file you need because that's all I restored), and enjoy the variety of custom ROMs these developers are building (because they are great!).
That's my $.02
EDIT: Oh and the Nandroid backups don't backup the EFS folder, so don't think a CWM backup will save you.
to those of you suggesting to back up nv_data.bin... just tell me where it is and i'll be glad to. i was no able to find it anywhere in /efs or /dev
artisticcheese said:
What did you to loose IMEI? What ROM did you f
flash or what did you do wrong to cause this? Better to learn from somebody's else mistakes then your own.
Click to expand...
Click to collapse
i am pretty use it happened when i flashed redruM onto my phone like a dumbass thinking [GSM Universal] meant it would work for my device
On the Captivate flashing a 1-click ROM would fix the issue. I have the issue too, but I really do not know what to do about it, I have looked all around the /efs partition, and I'm not sure where it could be.
DemonWav said:
On the Captivate flashing a 1-click ROM would fix the issue. I have the issue too, but I really do not know what to do about it, I have looked all around the /efs partition, and I'm not sure where it could be.
Click to expand...
Click to collapse
don't mean to discourage you, but i had to get a new device.
one thing that i wanted to try but could not was to take a stable EFS backup from an SGH-i747, locate the IMEI and change it to my own, and restore my /efs folder with those files. i'm not sure if decrypting the IMEI is possible, or if even getting to that point is possible.
if anyone has any ideas on how to extract an IMEI from an EFS backup feel free to PM me. i'm interested in experimenting on my personal backup (from my second device)
Ultimately if anyone should lose their IMEI or bork the EFS partition...these guys can fix it. They are very reputable and have fixed my Captivate back in the day....they now offer fixes for this device now. Its only 30 bucks and keep them in mind instead of paying 200 for insurance claims.
NO SPRINT OR CDMA models.
http://mobiletechvideos.mybigcommerce.com/
Well I will be getting a new phone on the 10th, but until then I would really like to figure out how to restore the IMEI. Who knows, it might not be possible at this point. When I get the new phone I will definitely be backing up my /efs directory, first thing. I completely forgot to do it, and it cost me.
How are you guys backing up the efs partition? Just a simple folder copy? Or a complete cwm backup?
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
So being careless, I forgot to make a backup and no the phone's IMEI number is not the original one on the back.
I've spent the whole day/night reading and grabbing files, modifying the QCN, restoring it, but I've failed so far.
It's my sister's phone I fudged up and I'd really like to fix it.
Can anyone point me in the right direction?
Please and thank you, I'm very desperate to fix it back /:
Model: T999L
4.3
Have you re-flashed 4.3 firmware with re-partitioning ? Make sure to use correct .PIT file. Create the QCN file after that.
Follow this guide. Yes I know its VZW. The fundamentals are same.
Hi ,
I lost my imei number with a wrong flash. I already flashed a couple of stock roms in hope I got the imei back but no luck. I have no backup and i was wondering if someone has a solution for me. I had this with my galaxy s2 also and someone send me an efs. tar file and it magically worked…. Pls someone have this magically efs file!
I remember somewhere in s4mini was a thread about restoring imei from a secondary partition or something all you needed to do is some commands in terminal emulator or adb
Hello all.
I replaced my n7100's motherboard with one i bought online. Works pretty well except that it would not register with my local telco. The sim is recognized, including the sim's mobile number and carrier. But no matter what, it won't register and get service. This happens with every sim from different telcos tried. The board was supposed to be unlocked.
Flashing different modems did not help. Neither did flashing different roms (stock and custom, it's currently on 4.2.2 and won't accept lower versions).
Finally i tried flashing an EFS backup i had taken from the old motherboard. Now the IMEI is 00499...
Before flashing the EFS I installed the N7100 EFS tool (from Dr. Ketan) it generated a single file backup (not a folder) and it's only a few KBs in size (while the old backup img was 20mb).
I've searched for solutions to the EFS situation but none worked so far.
Thank you for your time reading this and will appreciate any help that anyone can share.