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
Guys please help me, I flashed a wrong firmware to my GN2 I317M, i fllashed a n7105 firmware and the result was my phone can't see what I have in the internal memory, nor make calls or 3g, I have flashed the right firmware now several times but doesn't work I think that what could save me is to have the correct pit file for my phone so could be re-partioned the memory and be like new, but I couldn't find any so I have a cousin who has the exact model dou you think if I make a nandroid backup with his phone and restore it could help me I have backedup in my sd card the esf folder after make the restore could restore efs and succed? what you guys think? I am desperated...
Guys
What's the procedure for recovering the EFS on a GT-i8160? I don't have a backup of it and Galaxy toolbox says the device is not supported and wont save it (assuming coz it isnt on the phone). Because of this my EMEI is blank and I want to hexedit it back to the phone.
I am running stock jellybean. Any advice, step-by-step would be appreciated. cheers!
In many cases, missing (blank) IMEI could be done by a 3 parted flash using Odin.
Follow the instructions here: http://forum.xda-developers.com/showpost.php?p=64881061&postcount=3233
Files could be retrieved from http://d-h.st/users/ace2nutzer/?fld_id=0#files and http://xda.mister-freeze.eu/XDA-files/ace2nutzer/
I've bought used N910A phone and the EFS parition was corrupted, so it had to be wiped in service mode. The rest is working fine and after ODIN with stock rom + temporary root I can access to EFS partition, but it doesn't include anything so I need to put there content. The best way could be if somebody will give me the EFS partition backup then I will change IMEI and certificate for original one.
Thanks in advance for this. It will save my life!
You can PM to me if you don't want to share this EFS on the forum.
zencooler said:
I've bought used N910A phone and the EFS parition was corrupted, so it had to be wiped in service mode. The rest is working fine and after ODIN with stock rom + temporary root I can access to EFS partition, but it doesn't include anything so I need to put there content. The best way could be if somebody will give me the EFS partition backup then I will change IMEI and certificate for original one.
Thanks in advance for this. It will save my life!
You can PM to me if you don't want to share this EFS on the forum.
Click to expand...
Click to collapse
Can anybody help in this, please? It is very simply help, so any support will be appreciated.
Thanks in advance!
Doubt anyone here wants to share EFS files. When you talk about altering EFS and IMEI, you're getting into legal issues with phones.
jack man said:
Doubt anyone here wants to share EFS files. When you talk about altering EFS and IMEI, you're getting into legal issues with phones.
Click to expand...
Click to collapse
I whole heartedly agree. If you messed the phone up that bad you should mostlilely not be messing with it or take it to some place to service it for you.
And just an FYI i have seen alot of not so well english speakers askong for different parts of firmware or code of devices so the could build clones. I have been in the software and devices running linux code for over 10 years starting out with FTA (free to air) and we had a company out of south korea build our units and we did the code to make the set top boxes work. We many of our units cloned and our software stolen reversed and rebuilt to make it look like theirs. Thats why i got out of that business.
So thats why you are going to have a real hard time finding someone to share their efs partition. And you should always backup your device before doing anything to it ever and never ever aquire one with a missine imei or efs
giga8547 said:
I whole heartedly agree. If you messed the phone up that bad you should mostlilely not be messing with it or take it to some place to service it for you.
And just an FYI i have seen alot of not so well english speakers askong for different parts of firmware or code of devices so the could build clones. I have been in the software and devices running linux code for over 10 years starting out with FTA (free to air) and we had a company out of south korea build our units and we did the code to make the set top boxes work. We many of our units cloned and our software stolen reversed and rebuilt to make it look like theirs. Thats why i got out of that business.
So thats why you are going to have a real hard time finding someone to share their efs partition. And you should always backup your device before doing anything to it ever and never ever aquire one with a missine imei or efs
Click to expand...
Click to collapse
Of course I fully agree with you. I am android user since first android comercial impementation (on HTC G1), and of course I always make nandroid backup and EFS backup. This time it is completely different story. As I said I've bought phone with corrupted EFS partition, but full information about IMEI is available. So the only way to make this phone running is to get any EFS partition and change settings. For people having doubts: you can get rid IMEI from settings from the EFS partition. I just need the content to set up the rest.
Thanks in advance. Please PM to me if you can help me. Once again: thanks.