Galaxy S4 AT&T i337 New Security Firmware I337UCUAMF3 unlocked First in t Z3X BOX

Here is Step By Step Unlock Solution with Z3X Box,


Galaxy S4 AT&T i337 New Security Firmware I337UCUAMF3 unlocked First in the world

Selected model: I337
Selected port: COM11 Z3X BOX Serial Port
Selected port speed: 115200
Searching ADB device...
Please, allow USB debugging on phone... OK
Reading phone info...
Model: SAMSUNG-SGH-I337
Android version: 4.2.2
Product code: SGH-I337ZWAATT
Phone version: I337UCUAMF3
PDA version: I337UCUAMF3
CSC version: I337ATTAMF3
IMEI: 356565056990361
Phone S/N: R31D6181MHT
Checking Super user right... true
Writing data to phone... OK
Rebooting phone... OK
Checking phone at COM11 OK
Reseting... OK
Repair done
Done with Samsung Tool v.15.7



Step 1
Root your phone using this Great Solution, Click Here
VERY EASY ROOT PROCESS.
After Rooting Process complited, then Restart two times,


After That,

Step 2
connect phone into download mode by pressing vol- + home + power then vol up.

now tick EFS Clear and press flash.


after restart mobile press *#0808# and DM+Modem+ADB press ok
then *#9090# choice DM over UART
now connect usb cable with mobile and pc, ( usb Debug must enable, press Built Number 7 times in About phone for Develop mode on )

Now Final Step

do as showed in picture for Unlock.


After That, when Mobile will restart ontime, then connect UART Cable for Process Done.

Selected model: I337
Selected port: COM11 Z3X BOX Serial Port
Selected port speed: 115200
Searching ADB device...
Please, allow USB debugging on phone... OK
Reading phone info...
Model: SAMSUNG-SGH-I337
Android version: 4.2.2
Product code: SGH-I337ZWAATT
Phone version: I337UCUAMF3
PDA version: I337UCUAMF3
CSC version: I337ATTAMF3
IMEI: 356565056990361
Phone S/N: R31D6181MHT
Checking Super user right... true
Writing data to phone... OK
Rebooting phone... OK
Checking phone at COM11 OK
Reseting... OK
Repair done
Done with Samsung Tool v.15.7

Surprised... Unlock Done....!