I'm trying to find out what cell company this cell phones from? If anybody has any idea please let me know? I have a fido SIM card and it fits into the Samsung but has that lock icon on it.

  • How could we possibly know what provider the device is locked to when you have provided no information at all? You should ask the seller. – Matthew Read Jan 15 '15 at 19:51

The following sim-unlock procedure works for the Samsung Galaxy S4 (GT-9505 Model):

  1. Dial *#0011#


This will take you to the following screen 2. Press Menu button then tap "BACK"



  1. Tap on the Menu button again, but this time press Key Input.


  1. Enter 1 and Press OK


  1. Your are now in the SERVICE MODE MAIN MENU: Press 1 UMTS


  1. Press 1 DEBUG SCREEN


  1. Press 6 Phone Control


  1. Press 6NETWORK LOCK


  1. Then tap 3PERSO SHA256 OFF


  1. Go back to the UMTS MAIN MENU by pressing Menu then Back then tap 6COMMON


  1. Then select 6NV REBUILD


  1. Then tap 4RESTORE BACK UP


The Galaxy S4 will freeze, black screen, Blue LED Light, Menu and Back key ON. Wait for it to reboot (takes about a minute). Afterwards your device should be sim-unlocked.

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  • This only works on the oldest bootloader/Android version.. If the OP has updated at all this will not work. I've run into this issue myself, contacting the carrier fixed it easily. Alternatively if the above answer doesn't work you can buy unlock codes online and certain stores will do it for you. – RossC Jan 15 '15 at 15:43
  • @RossC - The great thing about the Galaxy S4, its bootloader is not locked from the factory. So you can reflash the device with the oldest firmware (including the bootloader) using odin. The firmware and odin can be found at www.sammobile.com/firmwares/ – Chrisii Jan 15 '15 at 17:33
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    Not as much as you would think! You can't revert certain versions of the bootloader and knox makes it worse. Once you are post 4.3 bootloader, going back is nigh on impossible for most users.(I'm assuming most users don't have a JTAG to hand) – RossC Jan 16 '15 at 8:24
  • @RossC, Yeah you're right. Most users do not have a JTAG on hand. I sincerely just assumed it was worth a shot because he didn't state anything in the question regarding: Firmware Version, Model Number, Provider etc. Sorry for all the turmoil. – Chrisii Jan 16 '15 at 9:10

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