Upgrade, Jailbreak, and Unlock iPhone 3GS New Bootrom
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boca123123 • April 20, 2013 at 5:46pm
I am currently running iOS 4.0 (8A293) with modem firmware 05.13.04 on an iPhone 3GS with the new bootrom. I need to upgrade to at least iOS 5.1.1 to run modern apps. Is it safe to upgrade while keeping the device unlocked, and is there a tutorial available?
Answers
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iClarified • January 13, 2026 at 2:56am
To upgrade your iPhone 3GS while preserving your unlock, you must avoid updating your baseband. Since you are on modem firmware 05.13.04, you have an unlockable baseband. You should update to iOS 6.1.6, which is the final version for the 3GS. Use a tool like RedSn0w to create a custom IPSW that does not include the baseband update. After installing the custom iOS 6.1.6, you can jailbreak and then install UltraSn0w from Cydia to unlock your phone. You can find specific guides for your device and firmware version using the iClarified jailbreak wizard here: www.iclarified.com/jailbreak/iphone3gs/os.php?os=6.1.6