Restoring your imei if you downgrade from 4.3 or 4.4 to a 4.2 based ROM or FTF (Sony FTF or custom ROM)
Symptoms of lost imei are non working cell reception, no data and the like. If you go to "settings / about phone / status" you will see that the imei is either 0 or many 0's. This happens becuase of imcompatable baseband/kernel.
Make sure you have a working backup of your data.
Download latest version of flashtool (link below)
Lost your IMEI
Follow these steps first:
Re-install the firmware that you came from and make sure IMEI is okorcome from a clean Stock Sony 4.3:
Come from a stock .290 or .136 so download that for your phone model if needed
Flash .290 or .136 all defaults if not coming from stock
Then follow the Downgrade path below, you can then flash any firmware or ROM before 14.2.A.0.290 / 4.3 without issue.
If you want to latter run a 4.3 or 4.4 based ROM you will have to flash atleast a 4.3 FTF so 14.2.A.0.290 or 14.2.A.1.136
Downgrade to gain root
Follow one of the Downgrade paths below to end up with a 14.1.B.1.532 firmware that is rootable while keeping your imei # intact and working cell/data
Flash EVERYTHING in this ftf, (use the defaults) it will do the downgrade below so you will end up on .532 with a working IMEI ready to root with bin4ry's tool http://forum.xda-developers.com/devd...ct/dl/?id=3442
You will end up with a device that thinks it is a C6833 but when you flash 4.3 or newer (.290 or .136) just use the one for your real model and the model number will be restored.
Downgrade path 2 (easy):
Download needed files
Download a suitable Sony firmware for your model from the ftf thread [see below] - .532
Download a suitable Sony firmware for your model from the ftf thread [see below] - Needs to be .257
It may pay to come from a stock .290 so download that as well
Flash .290 all defaults if not coming from stock - just to be safe
Flash .257 Untick Cache, Data and Apslog in the top [BOX]; Exclude system in the second [BOX];
Flash .532 Leave Cache, Data and Apslog ticked] in the top [BOX]; Exclude everything except kernel and system in the second [BOX];
You can untick the data wipe in both of the downgrade paths above if you want to keep user data, but may make it unstable. If you do decide to keep the data partition then wipe dalvik-cache to prevent bootloops and FC's
@[NUT] for new downgrade method and the one step FTF
Old instructions copied from OP, try these if the above fails:
This is a guide to restoring your imei if you downgrade from 4.3 or change to a custom ROM.
Symptoms of lost imei is no working cell reception, no data and the like. If you go to "settings / about phone / status" you will see that the imei is either 0 or many 0's
First up, make sure you have a working backup.
Refresh the firmware you just came from where imei was working
Check if imei is now restored.
Move on to Downgrade.
Download a suitable Sony firmware from the ftf thread - must be pre 4.3/14.2.a.0.290, I use 532 but others should work
Save to the firmware folder of flashtool
Make sure that the drivers for flashtool and the ultra are installed
Select flash - the lightning bolt
Select the firmware you just downloaded
Tick the exclude baseband box
Wait for flashtool to prepare the files
Make sure to turn your phone off
Place your phone in flash mode by holding down the down volume key while inserting the usb plug
Wait for it to flash
Install ROMs or FTFs as normal
I can't seem to find the original post that suggested the following solution (to credit), but I tried it and it worked fine for me. I updated to 4.3 right out of the box (got my Z Ultra just a few days ago) and made it quite difficult for myself, but I am now bootloader unlocked with my TA backed up and running CM10.2.
Here's how I did it (after reverting back to .532 to root and backup TA, unlock bootloader, I FTF'd back to .290).
From .290 (4.3), I fastboot flashed the boot.img from CM10.2, installed it and gapps, checked IMEI, it was all 0's (14 or 15 of them IIRC)
At this point, I put the phone into flash mode and FTF'd back to .257, except I did uncheck clear data, and checked the options to exclude flashing system and kernel partitions.
Rebooted into CM10.2 and I my IMEI was back, got signal from my carrier, and everything is working dandy. Rebooted into recovery to do a factory reset and set up from scratch just for kicks, IMEI still intact.
I used generic Europe FTFs for both .290 and .257
Downgrade option 4 (Untested by me):
Originally Posted by no name
You can try this method from 4pda:
1. Flash 14.1.B.2.257 from Flashtool with following parameters:
APPSLOG - checked
CHACHE - checked
DATA - unchecked
KERNEL - checked
SYSTEM - checked
Others - unchecked
2. Power on the phone (it will not boot) and power off with holding Volume up + Power
3. Flash 14.1.B.2.257 from Flashtool with following parameters:
APPSLOG - unchecked
CHACHE - unchecked
DATA - unchecked
KERNEL - unchecked
SYSTEM - unchecked
Others - checked
4. Repeat step 2
5. Flash 14.1.B.2.257 from Flashtool with default settings
For those wich downgrading from .290 to .257 , .532 or lower and still have imei loss issue:
Did u guyz tried to flash .290's baseband only over downgraded fw ??? i guess i saw that somewhere on z1 threads wich have same issue...
Also i guess when downgrading from 4.3 excluding system and kernel...u better to try it with data wipe ticked in flashtool.
The second solution worked for me. However, I did wipe data or else cm10.2 won't boot.
1. Be on 290 with UL bootoader.
2. Flash boot.img from cm10.2
3. Enter recovery and factory reset.
4. flash cm10.2 and gapps.
5. Boot in to cm10.2 and ignore initial setup process. Just skip skip skip.
6. When in home screen, open phone and dial *#06#. If you see IMEI lots of zeros, your OK.
7. Now turn off phone and ftf .257 but exclude system and kernel. Uncheck wipe data.
Wipe data for me was crucial as if I didn't I couldn't boot in to cm.
Sent from my Xperia Z Ultra using Tapatalk 4
Phone: Sony Xperia z2 16GB White
History: Too long to rabble here...
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