Good news for iPhone 4/iPhone 3GS owners that now there is a safe way to update to iOS 6 firmware and unlock your iPhone 4 or 3GS by preserving the baseband with Redsn0w 0.9.15b1 and use Ultrasn0w Fixer Patch. Latest version of Redsn0w 0.9.15b1 allow users to build custom iOS 6 IPSW firware files to preserve iPhone 4 or 3GS Baseband.
One can ask why is preserving the baseband is necessary, the answer to this question is Ultrasn0w 1.2.8 for iOS 6 is not released yet and users who rely on unlock will stuck on iOS 6 new basebands.
Preserve iPhone 4 or 3GS Baseband With Redsn0w 0.9.15b1 by Building Custom iOS 6 IPSW
Things you need to downlaod first:
- Download original iOS 6 IPSW for iPhone 4 (GSM) or iPhone 3GS directly from here.
- Latest version of Redsn0w 0.9.15b1 from here.
Step1: Now open up redsn0w and go to Extras > Custom IPSW.
Step 2: Point to the IPSW you just downloaded before. If you have a 3GS, you will prompted whether you have a 3GS with old or new bootrom. Select appropriately.
Step 3: Redsn0w will start building custom iOS 6 while removing the files that will update your baseband. Once completed, you will find this file on the same file path as the original IPSW with the prefix “NO_BB…” followed by the IPSW file name.
Step 4: Now pawn DFU your iPhone with redsn0w by going to Extras > Pwned DFU. Simply follow the on-screen instructions.
Step 5: Once your iPhone is in DFU, launch iTunes and press Shift+Restore (Windows) or Option+Restore (Mac). Be careful not to select the wrong IPSW during restore! If you get error 3194, you need to edit your hosts file.
Step 6:Wait for it to finish. Your iPhone will attempt to reboot and may stuck on the Apple logo with empty progress bar due to tethered jailbreak.
Step 7:Launch redsn0w again > Extras > Just Boot. Follow on-screen instructions.
Step 8:Your iPhone will boot up normally and to use ultrasn0w fixer to unlock your iPhone 4/3GS follow these instructions.