Jailbreak iPhone 4/3GS on iOS 4.3 with Sn0wbreeze 2.3b4 and Unlock with Ultrasn0w 1.2

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Good news for unlockers who are eager to have iOS 4.3 on their iPhone 4 or 3GS. It is now possible to jailbreak iOS 4.3 with sn0wbreeze and then unlock it with ultrasn0w.

Please note that only the following modem firmwares (basebands) are supported by ultrasn0w 1.2:

  • iPhone 4: 1.59.00
  • iPhone 3GS: 4.26.08, 05.11.07, 05.12.01, 05.13.04 and 06.15.00

The steps are the same as we posted last week – read full instructions here.

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

Download sn0wbreeze-v2.3b4.zip here.

Once you have jailbroken your device, follow the steps below to unlock it will ultrasn0w 1.2:

Before you start, please remove the SIM card from your iPhone.

Step 1: Launch Cydia from the springboard.

Step 2: Tap on Manage.

Step 3: Search for ultrasn0w on Packages in Cydia. If you cannot find it, add new Sources by typing: ‘repo666.ultrasn0w.com‘ (…sn0w = the digit zero, not O)

Step 4: A new ultrasnow package will be installed. Once done, go to Packages and look for ultrasnow. Tap and install it. During installation, you will see a black screen with running command lines.

Step 5: Reboot your iPhone and insert your SIM card. Toggle the Airplane mode to ON and then OFF. Your iPhone will search and register to your mobile phone network. Please be patient, sometimes it may take up to 3 minutes. If it doesn’t register, reboot your iPhone again.

Jailbreak iPhone 4/3GS on iOS 4.3 with Sn0wbreeze 2.3b4 and Unlock with Ultrasn0w 1.2 was last modified: March 21st, 2011 by Jonathan

Comments & Discussion

  1. So I currently have iOS 4.2.1 baseband 3.10.01. If I update my firmware to 4.3 will I be able to unlock?
    Which baseband do you get if you update to 4.3?

    • iPhone 4 – 4.10.01, 3GS – 5.16.xx, no, you won't be able to unlock them, that's why you need sn0wbreeze, it creates a custom firmware that prevents your baseband being updated

  2. So does this mean if my baseband is currently 3.10.01, this will not work for me? Even if I update my firmware to 4.3, I will not be able to unlock it via the above method? Appreciate the help.

    • it will not work, don't get confused with jailbreaking and unlocking – if your baseband is not one of the mentioned above you won't be able to unlock it. However, sn0wbreeze will preserve your baseband 3.10.01 which can be unlocked using Gevey Turbo SIM. See the link above.

  3. Luckily I have an factory unlocked iPhone 4 ! But my question is, like with many jailbreaks there occur to be problems with the battery or whatever! Is there any news regarding new problems that occur with this jailbreak?

  4. I have 3GS 4.1 06.15.00
    My GPS is not working !
    Is :
    – updating my Ipnon to 4.3
    – thin Jailbreakingit with Sn0wbreeze 2.3b4
    – thin Unlocking it with Ultrasn0w 1.2
    going to fix my GPS

    thank you

    • using sn0wbreeze will preserve the baseband, you won't be able to restore it directly via iTunes using original firmware, you will get an error message, GPS issue can't be fixed until there's a baseband downgrader available, currently it's only possible with a hardware downgrade (we provide this service)

  5. I'm experiencing a problem with my 3gs 4.3 bb 6.15. I successfully jailbreak and unlock it but when its idle and auto lock is on it goes back to DFU mode and i need to boot it again using ibooty. When i turn off auto lock it doesn't do that or when it's plug on to the laptop via usb even though auto lock is on it does not go onto DFU mode. Do you encounter any similar case? What do you think is the problem with it?

  6. You wrote: "Step 5: Reboot your iPhone and insert your SIM card. Toggle the Airplane mode to ON and then OFF. Your iPhone will search and register to your mobile phone network. Please be patient, sometimes it may take up to 3 minutes. If it doesnt register, reboot your iPhone again".

    Step 5: Reboot your iPhone and insert your SIM card…..after ultrasn0w installation when you suggest to "reboot" the device, I try to do it but my device don't start. It boot only if i don't install repo666.ultrasn0w or cydia upgrade. Can you help me?

  7. hi. im trying to unlock my iphone 3gs iOS 4.3. my baseband at the moment is 5.16. from the several guides that i have read, in order for you to change your baseband you must be at 4.2.1 or 4.1. however when i use a custom ipsw for 4.2.1 and try to restore with itunes i still get the error. is there anyway to unlock this fone or downgrade it?

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