Missing IMEI / No Mobile Data / Dev block / EFS Thread (UPDATE 7.16.12)

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zeesubalpha

Senior Member
Jul 3, 2012
200
40
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:
 
Last edited:

nunyabiziz

Senior Member
Jul 5, 2007
676
65
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
 
Last edited:

nunyabiziz

Senior Member
Jul 5, 2007
676
65
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
 

johnhazelwood

Senior Member
Oct 7, 2010
472
54
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
 

johnhazelwood

Senior Member
Oct 7, 2010
472
54
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.
 
Last edited:

zeesubalpha

Senior Member
Jul 3, 2012
200
40
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

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.

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
 

DemonWav

Senior Member
Sep 11, 2010
455
770
Lawton, OK
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.
 

zeesubalpha

Senior Member
Jul 3, 2012
200
40
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.

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)
 

DemonWav

Senior Member
Sep 11, 2010
455
770
Lawton, OK
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.
 

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  • 26
    Holy **** Batman!!

    Has anyone messed with QPST and CDMA Workshop? I connected my phone in "DM + Modem + ADB" mode and it was recognized by both programs. In CDMA workshop it was able to read the MEID / IMEI under the security tab. I tried to change the IMEI but it is for registered versions only.. So just wondering if anyone with the latest registered version has tried to read and write a new IMEI through cdma workshop?

    Holy **** batman!!! Lost IMEI and got it back think I just got lucky here still sweating bullets and taking a breather... I have been messing around with QPST since the IMEI issue first caught my attention. Got a bit daring and decided to force my IMEI to get wiped and succeeded to do it by pulling battery while flashing a ROM. Once IMEI was gone that's when the sweating and heart pounding began. Reconnected phone to QPST and restored NV. QPST after doing an NV restore attempted to restart phone but it failed and I was like oh ****...manually rebooted phone all the while thinking how crazy I was thinking to wipe IMEI purposely...waited...phone took longer to reboot than normal. When screen came on I saw a red circle with a line through it indicating no service then it turned to 4G LTE. I was still skeptical though because others had reported data after reboot. Went to settings and checked for IMEI and there it was!!!! I'm not saying this is a solution I am just saying it was restored for me. If anyone is interested in giving it a shot PM me...

    AT&T and TMO users you will need to follow the instructions and use the mod to get into DIAG mode provided by <:GeeK:> HERE be sure to thank him.

    You will also need to download QPST 2.7 build 323 (I have not been able to effectively use any other build since Qualcomm removes certain tools from later builds).

    I will edit this post with some more instructions once I catch my breath after almost losing my phone's functionality...

    DX
    17
    Awesome, but rather than updating your post buried in this thread, I (we) would ask that you instead create a new top-level "[HOWTO] Fix Your IMEI" thread to get stickied. :highfive:

    Just need one or two more confirmations...

    I did not want to create a new How To post for this yet as we have not completely confirmed it to work on multiple phones yet.

    Some info on what we have accomplished:

    I created an NV backup and purposely forced my phone to lose IMEI. My phone is a GSM phone on AT&T. I did this by interrupting a flash of a ROM during the flashing process in CWM. I have a feeling this may be a root cause to the lost of IMEI that maybe the data stream of reading a zip from our SD cards in CWM either due to some samsung code or something else or a lag in CWM for our phones is not allowing ROMs to fully get flashed (just a theory). My belief for that is because when I interrupted the flash I lost IMEI. After I successfully lost IMEI though pushing my NV backup in QPST restored it and phone has been fine since though I think I had a minor heart attack last night during the process lol.

    The second scenario was with PureMotive's phone that had no IMEI and no NV backup. We were able to successfully inject the IMEI back onto the phone using QPST. The phone had been unable to connect to Google play store and IMEI was a confirmed 0. After the process IMEI was confirmed returned and connection to Google play store was confirmed. This phone however is a CDMA phone on Verizon.

    With this small sample we cannot really confirm this to be a fix until we can get more testing and I don't want to jump the gun and have us thinking we got a fix. At this point it is still best to proceed with caution until we can confirm.

    I will not be home until later (somehow I still have a life beyond development and the wife says I have spent too many work till dawn nights on this the past few weeks...lol). But once home I will get more things out to you guys. Thanks for the patience. Stay tuned!!!

    DX

    Sent from my SAMSUNG-SGH-I747 using xda app-developers app
    14
    Instead of messing about with scripts, I will write you guys a windows app to automate all this for you! And ill even add an option to include or exclude certain partitions. :)

    Sent from my GT-I9100 using Tapatalk 2
    12
    More good news!!!!!!!!!!!!!!!!!!!!!!!!!!!

    Make sure you c/p'd it exactly. I got the same thing when I c/p'd it over from my computer - the 'let count=count-1;' bits didn't copy over for some reason.

    Some more good news!!! PureMotive a recognized developer from the Verizon S3 thread lost his IMEI the other night while testing an AOSP ROM. We had been going back and forth trying to get his IMEI back and he tried a method that I had suggested and he has confirmed to me just now that his IMEI is back!!!!! Anyone with a missing IMEI that is willing to give it a go PM me I want to confirm that this is indeed a fix before jumping the gun too fast!

    DX
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