Samsung "Network Unlock Unsuccessful" Troubleshooting

AltF4 · Feb 29, 2016

Now, regarding the "Network Unlock Unsuccessful" or "Code Error" issue there are a three troubleshooting guides:

SOLUTION #0
Insert a non accepted simcard and enter code when prompted for a code:

Enter Defreeze first if unsuccessful then Network.
If the same, enter Defreeze then Provider.
If the same, enter Defreeze then Sub Provider.
If the same, enter Defreeze then Extra.

Defreeze code = MCK
Network code = NCK
Sub provider code = SPCK

SOLUTION #1
A. For SAMSUNG Galaxy S4

1. Go to the Dial pad and dial *#0011#.
2. 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.
3. Click your MENU button AGAIN and this time click KEY INPUT. 
4. When the Key input box appears please input the number "1" and hit OK.
5. You will see a number 1 for a while, please wait until it changes into the SERVICE MENU.
6. Click [1] DEBUGGING SCREEN > [6] Phone Control > [6] Network LOCK.
7. You will see 3 OPTIONS within Network LOCK.
8. Click on number [1] Perso Sha256 INFO, the screen will change slightly
9. Hit the MENU button then when the menu pops up please carefully hit BACK to return to the previous screen.
10. Click on number [2] Person Sha256 ON, the screen will change again to a one line message.
WARNING!!! If you see two lines with a "NOT_CHANGE" and a [1] in the line please check the steps 10.1.-10.6 below (if not skip to step 11):
- 10.1. Hit MENU go back and select [3] Perso SHA256 OFF.
10.2. You will see TWO lines, please click the very first one which will say then MENU NOT EXIST.
10.3. Click MENU and go back a page.
10.4. Hit [1] Perso SHA256 info (make sure is says ENABLED_FLAG ... [0].
10.5. Hit menu go back.
10.6. Hit [2] PERSO SHA256 ON (make sure is still says ENABLED_FLAG [0]).
11. Immediately on the page with the ENABLED_FLAG[0] restart the phone on the screen by holding the power button and click RESTART.
12. When the phone prompts for the unlock code simply enter the unlock code (NCK/NETWORK) provided to you.
13. Your phone is now permanently unlocked!

B. For SAMSUNG Galaxy S2, Galaxy S3, Note, Note 2

1. Go to the Dial pad and dial *#197328640#
2. Click on number [1] UMTS > [1] Debugging screen > [8] Phone Control > [6] NETWORK LOCK.
3. You will see 3 options.
4. Click on number [1] Perso Sha256 INFO; the screen will change slightly.
5. Hit the MENU button then when the menu pops up please carefully hit BACK to return to the previous screen.
6. Click on number [2] Perso Sha256 ON; the screen will change again to a one line message.
7. Restart the phone on the screen by holding the power button and click RESTART.
8. When the phone prompts for the unlock code simply enter the unlock code.
9. Your phone is now permanently unlocked!

SOLUTION #2
Available to all models

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/DEFREEZE) and hit Unlock button.
3. You will get "unsuccessful message" again but don't worry.
4. Now type the Unlock code (Network/NCK) and hit Unlock button.
5. If phone say "Network Lock Successful" it worked and you may stop. If not, proceed to next step.
6. If you get "unsuccessful" again then hit Dismiss button and type *2767*3855# on phone keypad (CAUTION! This will reformat all your data!).
7. 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.
8. It will say "unsuccessful" again, don't worry! 
9. Type the Unlock code (Network or NCK code) and hit Unlock button.
10. Your phone should now give you the message "Network Lock Successful".
11. Now your phone is successfully unlocked!

SOLUTION #3
Available to all models

1. Turn off the Wi-Fi on your phone.
2. Stop the phone.
3. Remove SIM card.
4. Turn device ON without SIM card.
5. Once it's on go to phone dial screen and dial: *7465625*638*# it will bring you to the NETWORK LOCK screen.
6. In MCC/MNC field enter code for the service provider your phone is originally from (e.g. 31026 for T-Mobile USA). Check here for list of codes: Mobile country code - Wikipedia, the free encyclopedia. If your network has more than one mcc/mnc please try all of them this is very important.
7. In CONTROL KEY field enter the UNLOCK code received from us (NCK/NETWORK).
8. Hit OK - you should get a message: LOCK SUCCESSFUL.
9. Your phone is now unlocked.

Samsung "Network Unlock Unsuccessful" Troubleshooting

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