Samsung Galaxy S4 — Network SIM unlock code not working

  • Replies:0
  • OpenNot stickiedUnanswered

Mar 13, 2014 4:15:43 AM via Website

I paid to get an unlock code for my Samsung Galaxy S4 Active SGH-I537 locked to AT&T. I have tried to enter the unlock code given when the phone boots with my other carrier SIM card inserted, but get "Network unlock unsuccessful" error message.
I wrote to the company and they responded with the following instructions:

(Samsung Galaxy S4 Only)
Follow these step carefully, as long as you have the correct code it will work 100% (Your phone must be updated to the latest firmware!)
1. Make sure that the phone PROMPTS for the code with a NON accepted sim card and that your IMEI is correct by dialing *#06#

a. Go to the Dial pad and dial *#0011#
b. Please click your MENU button (Bottom LEFT button) and click BACK on the menu that appears, Nothing will happen do not worry please move to the next step
c. Please click your MENU button AGAIN and this time click KEY INPUT
d. When the Key input box appears please input the number "1" and hit OK
e. You will see a number 1 for a while, please wait until it changes into the SERVICE MENU
f. Please click [1] UMTS > [1] DEBUGGING SCREEN > [6] Phone Control > [6] Network LOCK
g. You will see 3 OPTIONS within Network LOCK
h. Please click on number [1] Perso Sha256 INFO, the screen will change slightly
i. Please hit the MENU button then when the menu pops up please carefully hit BACK to return to the previous screen
j. Next Please click on number [2] Perso Sha256 ON, the screen will change again to a one line message
NOTE: If you see ENABLE_FLAG[1], refer to the notes below. If you see ENABLE_FLAG[0], proceed with step k.
k. Restart the phone on the screen by holding the power button and click RESTART
l. When the phone prompts for the unlock code simply enter the unlock code provided to you
m. Your phone is now permanently unlocked!
*If this is not working, go to Solution #2
*NOTE - If it shows ENABLE_FLAG[1]:
Press menu, select back to go back to the Network Lock menu.
Select [3] Perso Sha256 OFF, then select the first item after.
It will say "Menu not exist".
Press menu, select back, press menu, select back to go back to the network lock menu again.
Select [2] Perso Sha256 ON again, it should now show Enable_Flag[0]
You may continue to step k in the previous instructions.

I cannot get pass step e. The Service Menu is inaccessible.


I write to them again and they send me the NCK Network unlock code along with the MCK Defreeze code and the following new set of instructions:

Try Solution #2
Follow these step carefully, as long as you have the correct code it will work 100%
1. Power off and on your phone with different network sim card. "SIM network unlock PIN" or "Enter Network Lock Control Key" screen will appear.
2. Type your Unfreeze code (MCK code) and hit Unlock button. You will get "unsuccessful message" again but don't worry.
3. Now type the Unlock code (Network or NCK code) and hit Unlock button.
*If phone say "Network Lock Succesful" it worked, but if not, proceed to step 4.
4. If you get "unsuccessful" again then hit Dismiss button and type *2767*3855# on phone keypad. (CAUTION! This will reformat all your data!)
5. After phone restarts, type the Unfreeze code (MCK code) when prompted to enter "SIM network unlock PIN" or "Enter Network Lock Control Key" screen and hit unlock button.
It will say "unsuccessful" again, don't worry!
6. Type the Unlock code (Network or NCK code) and hit Unlock button.
7. Your phone should now give you the message "Network Lock Successful"


I tried it, but couldn't get past step 4. After I enter the code *2767*3855# , it doesn't do anything.

Ok, so may third time is a charm? No.

Latest set of instructions:

1. Make sure that the phone PROMPTS for the code with a NON accepted sim card and that your IMEI is correct by dialing *#06#
a. Go to the Dial pad and dial *#197328640#
b. Please click on number [1] UMTS > [1] Debugging screen > [8] Phone Control > [6] NETWORK LOCK
c. You will see 3 options
d. Please click on number [1] Perso Sha256 INFO, the screen will change slightly
e. Please hit the MENU button then when the menu pops up please carefully hit BACK to return to the previous screen
f. Next Please click on number [2] Perso Sha256 ON, the screen will change again to a one line message
g. Restart the phone on the screen by holding the power button and click RESTART
h. When the phone prompts for the unlock code simply enter the unlock code provided to you
i. Your phone is now permanently unlocked!

This time I can not get into the UMTS MAIN Menu.

I have been given the Network unlock code, defreeze, provider and sub provider keys and none seem to work.

I am on Android version 4.3 and have never rooted and don't want to just yet. At least until the warranty expires.

Kernel version: 3.4.02-2244695
se.infra@R0302-03 #1
Build numer: JSS15J.I537UCUBML2
SE for Android status:
Enforcing
SEPF_SAMSUNG-SGH-I537_4.3_0016


Would appreciate any help.