Having a network locked device can really hamper how you use it, especially if the network isn’t of your choice. The operator would let you unlock your device for a small fee, not everyone might be that lucky. Imagine a scenario where you’re travelling abroad and want to use another network’s SIM card, only to discover that you cannot because of a carrier lock. Unlocking can really save you from quite a few hassles and tight spots.
Normally you can get almost any device unlocked by paying a small fee to carrier or to several online services that would let you purchase an IMEI unlock. Samsung has been more relaxed towards letting its users carry out a network/SIM unlock on their devices on their own, provided they knew the right steps to follow. Carrier unlock of Samsung Galaxy S III and Galaxy Note II is fairly easily without any specialized tool. Here, we’ll guide you through unlocking of the new flagship from Sammy, Galaxy S4 GT-I9505.
Playing around the carrier lock is risky business, and more complicated than your average Android modding. Follow these instructions at your own perusal. Also, this method applies to GT-I9505 only, and not to other variants of Galaxy S4.
Launch the Phone app on your Galaxy S4, and dial in: *#0011#
Press the Menu button followed by the Back key. Hit the Menu button again and select KEY INPUT. Enter 1 and press the OK button to enter ServiceMode.
Press Menu one more time and tap back again. This will pull up the Main Menu for ServiceMode.
Now select DEBUG SCREEN, followed by PHONE CONTROL.
You’ll get three options. Hit the one that says PERSO SHA256 OFF.
You need to get back to Main Menu. To do this, hit the Menu button followed by the Back key. In Main Menu, now pick COMMON, and then NV REBUILD.
The phone will tell you that a Golden Backup exists. Tap Restore Back-up.
Your device will now go through a series of “conditions”, where it will first freeze, then get on a black screen with Blue LED on and both capacitive buttons on, after which it will reboot automatically. The whole cycle might take a couple of minutes. Once it powers back on, it’s network unlocked, permanently.