How to Jailbreak and Unlock iPhone 3GS iOS 4.3 Baseband 5.16.00 with Sn0wbreeze 2.3

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UPDATE #2: Click here to officially unlock AT&T iPhone or click here for other worldwide network.

UPDATE #1: Read here to Jailbreak iPhone 4/3GS on iOS 4.3 with Sn0wbreeze 2.3b4 and Unlock with Ultrasn0w 1.2.

First and foremost – please read this carefully – this post will describe on how to jailbreak and unlock iPhone 3GS on iOS 4.3 with the new baseband 5.16.00. However, currently it is only possible to tethered jailbreak iOS 4.3 and there is still no unlock available for baseband 5.16.00. We will update this post as soon as a tool becomes available. The instructions below will guide you on how to jailbreak iPhone 3GS (technically it will also work on iPhone 4).

Jailbreaking iOS 4.3 is possible with sn0wbreeze 2.3b1. Since this is a tethered jailbreak, you will need your computer every time you reboot your iPhone. Mobile substrate is broken now fixed on iOS 4.3 so that means but ultrasn0w 1.2 will still not work and your iPhone cannot be unlocked on iOS 4.3 despite having an unlockable baseband. We hope that iPhone Dev Team will release redsn0w that supports iOS 4.3 soon. We have confirmed that redsn0w 0.9.6r8 is unable to recognize iOS 4.3 IPSW.

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

What you need:

  1. iPhone 3GS (iOS 4.3 is not supported on iPhone 3G)
  2. Sn0wbreeze 2.3 beta 1 [currently available for Windows only:]
  3. iOS 4.3 IPSW for 3GS [iPhone2_1_4.3_8F190_Restore.ipsw]
  4. iTunes 10.2.1 for Windows
  5. iBooty 2.0 which is already included in the package. It will be generated automatically on your desktop after sn0wbreeze created your custom IPSW.


1. Launch Sn0wbreeze, click the next “blue” colored arrow at the bottom right corner. Read the warnings!

2. You will get another warning that says “ARE YOU SERIOUSLY SURE YOU WANT TO DO THIS?” Now Drag and drop the IPSW you just downloaded or use the Browse function.

3. It will now ask whether you have an old or new bootrom. Select appropriately or you can also let sn0wbreeze detect your device.

4. Your IPSW is now verified. Just click next to continue.

5. Select which mode you are most familiar with. For beginners, use Simple Mode. Choosing “Baseband Preservation Mode” will create an IPSW but it does not jailbreak or unlock your iPhone.

6. If you choose Simple Mode, you will see an option to activate your iPhone. Click Yes or No according to your preference.

7. Your custom IPSW is now being built, sit back and wait or play PacMan.

8. Once your custom IPSW has been created, you will find it on your desktop along with iBooty v2.0.

9. Follow the on screen instruction to bring your device into DFU mode.

10. Once your iPhone is in DFU mode, launch iTunes and do a Shift+Restore and point it to the custom IPSW on your desktop. Sit back and wait until iTunes completes the restore.

Boot Tethered your iPhone with iBooty

Since there is no untethered jailbreak for iOS 4.3 yet, we will have to boot it into a tethered jailbroken state. We will use iBooty which can be found on your desktop.

1. Launch iBooty v2.0 from your desktop. Select your device and click Start to bring your iPhone into DFU mode.

2. Once your iPhone is in DFU mode, iBooty will do the rest, your iPhone will boot up into jailbroken state.

Unlocking your iPhone

As mentioned above, there is no tool available to unlock your 3GS. We expect iPhone Dev Team to update redsn0w and they will probably use the same method of flashing the baseband to 6.15.00 and then unlocking your iPhone with ultrasn0w. We also hope that they can develop the baseband downgrader that can downgrade your iPhone baseband from 5.16.00 to 5.13.04 which can be unlocked using ultrasn0w.

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How to Jailbreak and Unlock iPhone 3GS iOS 4.3 Baseband 5.16.00 with Sn0wbreeze 2.3 was last modified: October 18th, 2012 by Joe Wang

Comments & Discussion

  1. Pingback: Jailbreak iPhone 4/3GS on iOS 4.3 with Sn0wbreeze 2.3b4 and Unlock with Ultrasn0w 1.2 |

  2. I had the same problem, Accidentally upgraded to 4.3 and my phone was bricked for a week.

    But I was able to get out of this by downgrading to 4.1 via tinyumbrella. Now my problem, is it is now jailbroken but still locked . It is 4.1 version but the firmware is 5.16.01. What to do now? I basically have an ipod touch instead of an iphone. Help!!!

  3. Any new info to UNLOCK baseband 05.16.01 and Firmware 4.3 on 3Gs iphone? I am only seeing updates to the 4.3.1 firmware. I believe the new Ultrasn0w is only for previously jailbroken versions

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