Originally Posted by yoonus
Just confirmed bootloader and baseband are I747UCDMG2.
I will update here how everthing goes.
PS: I DON'T want to go to I747UCUEMJB bootloader after unlock. That will mean, I will not be able to downgrade in future. AFAIK, I747UCUEMJB bootloader is also locked.
Thanks all for the assurance and support.
I was able to ODIN to stock ROM and SIM unlock the phone.
Background: My ATT S3 i747 was running CM11 Android 4.4.4. Baseband and Bootloader was I747UCDMG2.
1. Flashed rooted stock ROM (root66_ATT_I747UCDLK3.7z) using odin from http://forum.xda-developers.com/show....php?t=1739426
Followed the steps in OP.
After flash ODIN showed PASS and phone rebooted. It was stuck in Samsung logo. I booted into recovery. Performed a wipe cache and factory restore.
Phone rebooted successfully after that.
2. Inserted non-ATT SIM and it asked for the unlock code. I had obtained the code from ATT before. Used the code and phone was unlocked.
The same code did not work while I was running CM11.
NOTE: When running stock ROM you can follow steps in below threads if direct unlock did not work for you.
This works only with stock 4.1.1 image (LK3 modem).
NOTE: If you need TWRP recovery, see http://forum.xda-developers.com/show....php?t=1739426
and search for "Odin Flashable TWRP Recovery" in OP.
You can download ODIN flashable TWRP from there.