Safely Update to iOS 5.1.1 and Unlock iPhone 4 or 3GS with Sn0wbreeze Custom Firmware

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If you use ultrasn0w or Gevey SIM to unlock your iPhone, here’s the ultimate guide to safely update to iOS 5.1.1 while preserving your baseband.

UPDATE: If you own an AT&T iPhone, unlock it permanently using this.

UPDATE: If you’re tired of messing around with jailbreaking/unlocking, AT&T iPhone can now be permanently unlocked. Unlock it here!

Editor's note: learn more by reading our ebook on starting your own iPhone repair & unlock business

You’ve probably read the following countless times, but if you’re new to using locked iPhone, it may be worthwhile to read and understand the points below:

  • Custom firmware allows you to restore your iPhone without updating the baseband.
  • By preserving the baseband, you can continue unlocking your iPhone; either with ultrasn0w or Gevey SIM depending on your iPhone or baseband version.
  • There’s no known software method to downgrade your baseband, once it’s updated, there’s no turning back. However, we do offer chips replacement for iPhone 4 or 3G/3GS.
  • With sn0wbreeze 2.9.5 (Windows only), it can untethered jailbreak iOS 5.1.1 and below.
  • If you’ve downgraded your baseband chip with us, this guide will be useful for you. Under no circumstances you should restore using stock firmware.

What you need:

  • iPhone 4 with baseband 01.59.00 (unlock with ultrasn0w) or 02.10.4, 03.10.01 and 04.10.01 (unlock with Gevey SIM). Baseband 04.11.08 or 04.12.01 cannot be unlocked or downgraded.
  • iPhone 3GS with baseband 05.11.07, 05.12.01, 05.13.04 or iPad baseband 06.15.00
  • Sn0wbreeze 2.9.5
  • Ultrasn0w Fixer for iOS 5.1.1
  • Ultrasn0w 1.2.5

Note: Currently, there’s still no way to preserve iPhone 4S’ baseband. You can still unlock baseband 2.0.12 and below using Gevey Ultra S.

Before you begin, always remember to backup your iPhone.

Part One: Building and Installing Custom iOS 5.1.1 Firmware (Baseband Preserved)

The first part involves the building and installing custom iOS 5.1.1 firmware. ‘Hacktivation’ is needed if you don’t have the official SIM card. The second part of this tutorial explains the steps to unlock your iPhone: Part 2(a) is using ultrasn0w for supported baseband only  or Part 2(b) is for Gevey SIM for iPhone 4.

You can also download these ready made custom iOS 5.1.1 firmware for iPhone 3GS or iPhone 4 (hosted on filefactory, membership required). Mac users can use the latest redsn0w to pawn DFU before restoring.

1. Download original iOS 5.1.1 firmware (IPSW) for iPhone 4 or iPhone 3GS directly from Apple. It’s highly recommended that you save it locally for future use.

2. Download Sn0wbreeze 2.9.5 from

3. Start sn0wbreeze.

4. Click browse and locate the original iOS 5.1.1 that you just downloaded.

5. Sn0wbreeze will identify the IPSW file. Click Next.

6. Choose one of the modes below:

  • iFaith Mode: Builds custom iOS and stitches it with your saved SHSH.
  • Expert Mode: Preserves your baseband, will jailbreak and hacktivate (activate).
  • Simple Mode (recommended): Preserves your baseband, will jailbreak and hacktivate.
  • Baseband Preservation Mode: Preserves your baseband, but will not hacktivate or jailbreak. You will need your official SIM card to activate it after restore.

7. Now it will ask you whether you want to hacktivate or not. Select “Yes”. Now wait until sn0wbreeze completes the custom iOS 5.1.1 for you.

Once the custom iOS 5.1.1 is ready you will find it on your desktop. Before restoring your iPhone, you MUST put your iPhone into pwned DFU mode. This allows it to accept custom firmware. Otherwise, you’ll get an error message during restore. iREB will appear as soon as custom firmware is built. You can also access it on the menu bar of sn0wbreeze.

To begin restoring, be sure your iPhone is already in pwned DFU mode (black screen) then launch iTunes, press shift on your keyboard and click restore. Select the custom firmware that was just created. To be sure, the file name always begin with sn0wbreeze_iPhone_xxxxxxx.

If you get error 3194, use this guide to fix it. For other iTunes errors, refer to this.

Part Two (a): Unlock with ultrasn0w 1.2.5 1.2.7 from Cydia [for supported baseband only]

There’s no official ultrasn0w for iOS 5.1.1 yet, so we’ll need to install ultrasn0w fixer iOS 5.1.1 first.

1. Launch Cydia and add the following repo by going to Manage > Sources > Edit > Add:

2. Search for ultrasn0w fixer for iOS 5.1.1 and install it.

3. Finally, search for ultrasn0w (1.2.7) and install that too.

4. Reboot your device.

Part Two (b): Unlock with Gevey SIM [for iPhone 4 baseband 02.10.01, 03.10.01 or 04.10.01 only]

1. Eject your SIM tray and reboot your iPhone.

2. Once restarted, unlock your screen. Turn off 3G and cell data (you can turn these on later). Insert your SIM tray along with your SIM card and Gevey SIM.

3. Wait for Accept Screen. Tap Accept.

4. You will see No Service (in iOS 4.x, you will see one signal bar). Wait for 15-20 seconds and dial 112. Hang up after 1-2 seconds.

5. Turn on Airplane Mode and wait for ‘NO SIM CARD INSTALLED’ message. Turn off Airplane Mode and you will see ‘SIM FAILURE’ and tap OK. Your iPhone will connect to your network now.

That’s it! Your iPhone is now unlocked on iOS 5.1.1 along with untethered jailbreak.

If you find this post useful, please do us a small favor by clicking ‘LIKE’ or ‘Recommend on Google+’ below.

Safely Update to iOS 5.1.1 and Unlock iPhone 4 or 3GS with Sn0wbreeze Custom Firmware was last modified: September 14th, 2012 by Joe Wang

Comments & Discussion

  1. hey i got iphone 3gs ios4.1 (8B117) and BB 06.15.00 that ALREADY jailbreak,
    so, can i use this method to upgrade my ios from 4.1 to 5.1?

  2. hi buddy, saw ur video, really excellent 1. i hope u can help me out, i have iphone4 ios5.1(9b176) bb 4.10 unlocked by gevey. please tell me how to do untethered jailbreak of my phone. i'll be thankfull if u really help me out.

  3. hi again, sorry to bother u again. but i cldnt understand. firstly u said use redsnow now u r telling to use snowbreeze. and even i used the above method when i select browse ipsw and i select the one i downloaded it says INVALID IPSW 6343xxxxxxxxxx something like this. Please some1 help. its seriously will be very gr8full of you.

  4. Can I use it to upgrade my iPhone 3GS iOS 4.1 baseband 05.13.04 to iOS 5.1.1. I recently downgraded it from baseband 06.15.00 to 05.13.04. It won’t create any problem will it?

  5. I have an iphone with firmware 4.3.5 with bb 4.10.01 unlock by gevey sim and its jailbroken.. Will it work for me to upgrade to 5.1.1 Thanking in advance for your help :) and also by the way my jailbreak is only tethered..

  6. Hi! I have an iPhone 3Gs iOS 4.2.1 and my baseband is 6.15.00 can I still use this method to update my iPhone and will it be already unlocked or I should unlock it again??

  7. hey!! i upgrade from ios 4.1 to ios 5.1.1 but my iphone 3gs fabricated in 2011 week 27 stuck on yellow screen with vertical strips just it can't boot up . need help. thnx while am waitin for u'r help

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