How to Update iPhone 3GS from iOS 4.1 to 5.1.1 with iPad Baseband
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shikhardadhich • December 27, 2012 at 2:27am
I have an unlocked and jailbroken iPhone 3GS running iOS 4.1 with the 06.15.00 iPad baseband and the old bootrom. I want to upgrade to iOS 5.1.1 while preserving my ability to unlock the device. What are the specific steps and precautions I should take for this upgrade?
Answers
0
iClarified • January 12, 2026 at 4:33am
To update an iPhone 3GS with the 06.15.00 iPad baseband to iOS 5.1.1, you must use a custom firmware (IPSW) to prevent the baseband from being updated or causing an error during the restore process. Since you have the old bootrom and SHSH blobs, you have significant flexibility.
1. Download the iOS 5.1.1 IPSW for the iPhone 3GS.
2. Use a tool like Redsn0w or PwnageTool to create a 'No Baseband' custom firmware. This ensures your iPad baseband remains intact so you can continue using Ultrasn0w for unlocking.
3. Put your iPhone into Pwned DFU mode using Redsn0w before attempting the restore in iTunes.
4. In iTunes, hold the Shift key (Windows) or Option key (Mac) and click Restore, then select your custom IPSW.
5. Once updated, you can jailbreak using Redsn0w or Absinthe and then install Ultrasn0w from Cydia to regain your cellular service.
Because you have the old bootrom, your jailbreak will be untethered regardless of the firmware version.
1. Download the iOS 5.1.1 IPSW for the iPhone 3GS.
2. Use a tool like Redsn0w or PwnageTool to create a 'No Baseband' custom firmware. This ensures your iPad baseband remains intact so you can continue using Ultrasn0w for unlocking.
3. Put your iPhone into Pwned DFU mode using Redsn0w before attempting the restore in iTunes.
4. In iTunes, hold the Shift key (Windows) or Option key (Mac) and click Restore, then select your custom IPSW.
5. Once updated, you can jailbreak using Redsn0w or Absinthe and then install Ultrasn0w from Cydia to regain your cellular service.
Because you have the old bootrom, your jailbreak will be untethered regardless of the firmware version.