How to upgrade iPhone 3GS from jailbroken iOS 5.1.1 to 6.1.2
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tigeriser • March 2, 2013 at 8:41pm
I have an iPhone 3GS (Old Bootrom) running a jailbroken version of iOS 5.1.1 and unlocked with the 06.15.00 iPad baseband. I want to upgrade to an untethered jailbreak on iOS 6.1.2 while maintaining my carrier unlock. Do I need to modify the baseband first, and which tools are required for the upgrade, jailbreak, and unlock process?
Answers
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iClarified • January 12, 2026 at 8:35pm
To upgrade an iPhone 3GS with the iPad baseband from iOS 5.1.1 to 6.1.2 while maintaining an unlock, you should follow these specific steps.
First, it is highly recommended to downgrade your iPad baseband (06.15.00) to a standard baseband (05.13.04) before moving to iOS 6. You can do this using Redsn0w 0.9.15b3. Select your current iOS 5.1.1 IPSW in the software and choose the option to downgrade the iPad baseband. This restores GPS functionality and provides a more stable foundation for the unlock.
Second, to upgrade to iOS 6.1.2 without updating the baseband further, use Redsn0w to create a custom IPSW or use its built-in Restore feature. Do not use a standard iTunes restore, as this will update the baseband to a version that may not be unlockable.
Third, once the device is running iOS 6.1.2, use the Evasi0n jailbreak tool to perform an untethered jailbreak. This version of Evasi0n is specifically designed for iOS 6.0 through 6.1.2.
Finally, open Cydia and search for the Ultrasn0w package. Install it to unlock your device for use with other carriers. Because you downgraded to baseband 05.13.04 in the first step, the unlock will be fully compatible and stable.
First, it is highly recommended to downgrade your iPad baseband (06.15.00) to a standard baseband (05.13.04) before moving to iOS 6. You can do this using Redsn0w 0.9.15b3. Select your current iOS 5.1.1 IPSW in the software and choose the option to downgrade the iPad baseband. This restores GPS functionality and provides a more stable foundation for the unlock.
Second, to upgrade to iOS 6.1.2 without updating the baseband further, use Redsn0w to create a custom IPSW or use its built-in Restore feature. Do not use a standard iTunes restore, as this will update the baseband to a version that may not be unlockable.
Third, once the device is running iOS 6.1.2, use the Evasi0n jailbreak tool to perform an untethered jailbreak. This version of Evasi0n is specifically designed for iOS 6.0 through 6.1.2.
Finally, open Cydia and search for the Ultrasn0w package. Install it to unlock your device for use with other carriers. Because you downgraded to baseband 05.13.04 in the first step, the unlock will be fully compatible and stable.