This post was updated on 27 May 2014
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Having a network-locked device can sometimes become problematic for those who plan to sell on their upgrade or switch networks. It becomes even worse for those bound to business contracts which remove the freedom of using your smartphone abroad with the fear of driving up your phone bill due to roaming. After several YouTube tip-offs we can confirm there is a method to unlocking your Samsung Galaxy S4 GT-19505 without any downloads, tools or purchases.
It seems like there is a Golden Backup left in the device’s OS – perhaps from before your carrier altered the UI – which enables you to restore to pre-network lock settings. This method will most likely wipe any advantages your carrier may have installed as an addition to Android UI interface. The Samsung TouchWiz seems to be unaffected.
As always, Technouz cannot be held responsible for any damages caused to you or your device as a result of following this tutorial. We strongly discourage you from tampering with your devices without seeking professional advice as it may void your warranty. But since this is a platform dedicated to getting the most out of your tech – here goes!
A full list of networks this has been confirmed working with can be found at the bottom of this page. If this tutorial worked for you, please let us know!
Note: This tutorial only applies to the Samsung Galaxy S4 GT-I9505 model!
Step 1: Launch the phone app on your S4 and dial in *#0011#.
Step 2: Press the Menu button followed by the Back key. Then hit the Menu button again and select KEY INPUT. Enter the number 1 and press the OK button to enter ServiceMode.
Step 3: Press Menu and tap back. This will pull up the Main Menu for ServiceMode. Now tap the first option:  UMTS.
Step 4: Select the first option:  DEBUG SCREEN; followed by:  PHONE CONTROL.
Step 5: From the next screen select the sixth option:  NETWORK LOCK.
Step 6: Now you will get three options. Select the option that says: PERSO SHA256 OFF.
Step 7: Now you need to get back to the Main Menu where we started. To do this, hit the Menu softkey and then the Back key. Now you are back in the Main Menu, select option six:  COMMON, followed by:  NV REBUILD.
Step 8: The device will now tell you that a ‘Golden Backup’ exists. You must restore this backup by tapping the fourth option on your screen:  Restore Back-up.
Step 9: Your device will now go through a series of software restores where your phone may freeze and result in blank screens. This process can take a while (upto an hour). Once the process has completed, your device will reboot automatically. Once powered back on – it’s network unlocked, permanently! Congratulations!
Confirmed list of compatible networks: