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  UMTS >  DEBUGGING SCREEN >  Phone Control >  Network LOCK
g. You will see 3 OPTIONS within Network LOCK
h. Please click on number  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  Perso Sha256 ON, the screen will change again to a one line message
NOTE: If you see ENABLE_FLAG, refer to the notes below. If you see ENABLE_FLAG, 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:
Press menu, select back to go back to the Network Lock menu.
Select  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  Perso Sha256 ON again, it should now show Enable_Flag
You may continue to step k in the previous instructions.
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”
Now your phone is successfully unlocked!
*If this is not working, go to Solution #3
1. Turn off the Wi-Fi on your phone and then turn device ON without SIM card.
Once it’s on go to phone dial screen and DIAL: *7465625*638*#
it will bring you to the NETWORK LOCK screen.
– in MCC/MNC field enter code for the service provider your phone is originally from (eg 31026 for T-Mobile USA)
check here for list of codes: http://en.wikipedia.org/wiki/Mobile_Network_Code
*If your network has more than one mcc/mnc please try all of them this is very important
– in CONTROL KEY field enter the UNLOCK code
– hit OK
– you should get a message: LOCK SUCCESSFUL
Power phone down, insert SIM card you want your phone to work with and power on.