Unlock your Samsung Galaxy Express AT&T i437P
Unlock your Samsung Galaxy Express AT&T i437P FREE!!
This is for who have 4.1.2 firmware ONLY and canīt unlock using unlock code.
Took me a long time, but now a have my i437P unlocked.
Just follow the steps.
root your phone follow this
Donīt install CM10.1 or CM10.2 now. You are going to do this later.
Create a backup.
Wipe data/factory reset, wipe cache partition and dalvik cache (found in advanced)
download 4.0.4 firmware from sammobile.com SGH-I437 USA (AT&T) 4.0.4
This firmware is for the model i437, not for i437P, but works.
You goin to lose Wifi and Bluetooth but donīt worry.
Use Odim and put 4.0.4 firmware. You goin to lose root, but no problem.
Donīt use any sim card for now.
Lets unlock the phone using this code:
Just dial the following keys *#197328640#
 Debug Screen
 Phone Control
 Network Lock
Perso SHA256 OFF
(after choosing this option, wait about 30 seconds, then go back one step by pressing the Menu button then select Back, now you are in
 Network Lock then choose
 NW Lock NV Data INITIALLIZ ..... wait for a minute then reboot your phone
put your sim card and your phone is unlocked.
Now lets go back to 4.1.2
repeat the steps to root your phone.
Restore the backup made by clockworkmod.
Follow the steps "You will likely run into issues with non functional WiFi. To resolve this, after flashing the ROM, follow these simple steps:" in this
Than install CM10.2 that works FINE!!!
Thanks jt1134 for CM10.2 and AwesomeTurtle that help me.
Sorry for my bad english.