[GUIDE] Galaxy S4 Sim-Unlocking

[GUIDE] Galaxy S4 Sim-Unlocking

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Follow steps carefully and correctly.[COLOR=LemonChiffon]
Instructions:
METHOD 1
1. Dial *#0011#

2. press Menu then tap BACK

3. press the Menu again the tap KEY INPUT then enter 1, press OK button
4. press Menu then tap BACK
Your are now in the SERVICE MODE MAIN MENU

Tap [1]UMTS 

then [1]DEBUG SCREEN 

then [6]PHONE CONTROL 

then [6]NETWORK LOCK 

then tap [3]PERSO SHA256 OFF

Go back to the UMTS MAIN MENU by pressing Menu then Back then tap [6]COMMON

then [6]NV REBUILD

then tap [4]RESTORE BACK UP

the device will freeze, black screen, Blue LED Light, Menu and Back key ON. Wait for it to reboot (about a minute).
Your Samsung Galaxy I9505 is now Sim-Unlocked.




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METHOD 2 - artnada
This is what I did. Slightly different to OP.
I did this with my AUTHORISED Sim in first.

1. Dial *#0011#
2. press Menu then tap BACK
3. press the Menu again the tap KEY INPUT then enter 1, (wait a few seconds) it auto jumped into service menu.
4. press Menu then tap BACK (not needed for me)
Your are now in the SERVICE MODE MAIN MENU
Tap [1]UMTS (may auto go into next menu (mine did)
then [1]DEBUG SCREEN 
then [6]PHONE CONTROL
then [6]NETWORK LOCK
then tap [3]PERSO SHA256 OFF
Go back to the UMTS MAIN MENU by pressing Menu then Back (several times) 
then tap [6]COMMON
then [6]NV REBUILD (if this does not work next time)
do [4]RESTORE BACK UP
the device will freeze, black screen, Blue LED Light, Menu and Back key ON. Wait for it to reboot (about a minute).
Your Samsung Galaxy I9505 is now Sim-Unlocked.
Edit: 
When I booted back in with AUTHORISED sim, I had to turn off Mobile Data, then turn it on. 
I then turned off the phone, put my UNAUTHORSIED Sim in, booted back up and NO NETWORK PIN request!
Again, I had to turn off Mobile data, then turn it back on. The UNAUTHORSIED Sim worked!!! 
My previously locked to Three UK GT-I9505 is now unlocked to all networks  Thanks again to XDA (Y)

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It has been reported that this is indeed a "permanent" unlock:
artnada's tests:
I had sim unlocked my phone when I was on the "djemby" pre-rooted I9505XXUAME2-DEODEXED-KNOX-FREE-HD-VOICE 
I have just re-flashed my original factory Three ROM. I9505XXUAMDC_I9505H3GAMD6_I9505XXUAMDC_HOME and the Sim unlock was still UNLOCKED!
I then re-flashed back to I9505XXUAME2-DEODEXED-KNOX-FREE-HD-VOICE.tar.md5 and the sim unlock was still UNLOCKED!
So, I think we can safely say this sim unlock method is a permanent unlock!