How To Unlock iPhone 3GS Running iOS 5.1 Baseband 5.16.05 [Guide]
Though a lot of iPhone 3GS owners know that they can unlock their iPhone 3GS locked on baseband 5.16.05 by patching iPad’s baseband 6.15.00. But as you all know the Apple has pushed their major iOS 5.1 update and some iPhone 3GS users were not aware of the fact that their baseband will also get update to 5.16.05 which is not unlockable. There’s something interesting about iPhone 3GS’ baseband chip which allows you to patch iPad’s baseband over its original baseband which results in an unlocked iPhone 3GS. The process is not complex but it requires a lot of patiences, if you you recently updated your iPhone 3GS to iOS 5.1 then it is highly likely that you’ve also updated your baseband to 5.16.05 and there’s no unlocking solution available for this specific baseband. But there’s a workaround which will allow you to use your iPhone 3GS again. 
Note: Before you continue there are couple of things which you should know, in some cases flashing iPad’s baseband 6.15.00 will break your GPS but thanks to iPhone-Dev team and iH8Sn0w this is issue has been resolved. You won’t be able to restore stock IPSW file once you flash iPad’s baseband.
Important: If your iPhone 3GS was manufactured after 25th week of 2011 then DO NOT follow this guide or it will brick your iPhone 3GS’ baseband chip. You can check manufacturing week of your iPhone 3GS by following a simplet guide posted here.
Let’s begin
Things you will need during this process:
- Latest version of iTunes (Download)
- Sn0wbreeze 2.9.3
- iOS 5.1 IPSW file for iPhone 3GS (Download)
Step 1: Run Sn0wbreeze 2.9.3 which you downloaded from the link above, don’t forget to run Sn0breeze 2.9.3 in Administrator mode
Step 2: Click on the blue arrow and you will be asked to select IPSW, browse you computer and locate iOS 5.1 IPSW file you downloaded earlier.
Step 3: Sn0wbreeze will verify your iPhone 3GS’ iOS 5.1 IPSW and give you an option to choose your bootrom. If you don’t know whether your iPhone has Old Bootrom or New Bootrom you can just click “I don’t know or New Bootrom”
Step 4: Click on the big blue arrow and select expert mode. After selecting expert mode Sn0wbreeze will take you through some basic steps make sure to check Hacktivate (Activate iPhone) it is necessary for people who rely on unlocking.


Step 5: In this step sn0wbreeze will ask you whether you want to patch iPad’s 6.15.00 baseband or not, CHECK this option and a warning window will pop that’s normal press “Ok” and continue

Step 6: Click ‘Build IPSW’. Since building custom firmware may take some time, you can optionally play Pac-Man game to kill some time.

Step 7: Sn0wbreeze will create iOS 5.1 custom IPSW firmware file on your desktop. Now you will be asked to put you iPhone 3GS in “pwned DFU” mode in order to restore the custom firmware file you just created.
Step 8: Follow the on screen instruction to out your iPhone 3GS in pwned DFU mode.
To enter DFU mode:
- Hold Power and Home buttons for 10 seconds
- Now release the Power button but continue holding the Home button for 10 more seconds
- You device should now be in DFU mode
If you have followed the steps correctly, sn0wbreeze will confirm that your iPhone 3GS is in PWNED DFU state.
Restore iOS 5.1 Custom Firmware Using iTunes
Start iTunes, click on your iOS device icon from the sidebar in iTunes. Now press and hold Left “Shift” button on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in iTunes and then release this button.
Select the pre-jailbroken custom IPSW that was created (must be on your desktop) and click the Choose button.
Sit back and relax iTunes will restore pre jailbroken custom IPSW file on your iPhone 3GS.
Important: DO NOT disconnect your iPhone 3GS during this process.
As this is a tethered jailbreak so you will need to boot your iPhone 3GS in tethered mode you can do so with redsn0w or iBooty but we recommend iBooty.
Booting In Tethered Mode:
Step 1: Open iBooty 5.1 folder which was created on your desktop and run iBooty 5.1
Step 2: Select your device and follow the instruction on screen to put your iPhone 3GS in pwned DFU mode to boot in tethered mode.
Now comes the unlocking part, as you know iPhone-Dev announced that they will release Ultrasn0w compatibility update for iOS 5.1 but there has been no update on this compatibility update but you can follow our guide posted here to unlock your iPhone 3GS running iOS 5.1 with ultrasn0w fixer.
That was it guys you should have your unlock iPhone 3GS kicking latest iOS 5.1. Feel free to contact us if you face any issues.
We will keep you updated on this, stay tuned!
Make sure to follow us on Twitter and join our Facebook page for latest news, App reviews, updates and tutorials/How to guides.









