Upgrade iPhone 4 to 4.1 iOS preserving Unlocked Baseband 01.59.00

Apple has not let Hackers play with its iDevices easily and if they manage to intrude then Apple rushes to patch the vulnerabilities. The possessive nature of Apple is also one of the reason iPhone is not available on carriers other than AT&T in USA. The Hackers usually come up with an iPhone unlock by exploiting baseband but Apple tends to fix it in next firmware update.

Apple had patched the baseband last time in 3.1.3 firmware which was later on unlocked after 4.0 and 4.0.1 release. Yesterday, Apple released iPhone 4.1 iOS which once again patched the latest exploit. It has been seriously warned to iPhone unlockers to stay away from 4.1 update specially iPhone 3GS/3G users. As of Today, those who upgraded iPhone 3G[S] to 4.1 iOS are out of luck possibly forever as they cannot downgrade baseband and new baseband exploit is extremely difficult to be find out.

iPhone 4 users are in luck as they can downgrade baseband and also update to 4.1 iOS using new TinyUmbrella 4.1.3. If you wanted to test iPhone 4.1 iOS and preserve your unlock then you can try this.

Note: Upgrading to iPhone 4.1 iOS with TinyUmbrella will preserve you unlocked baseband but it will wipe your jailbreak and there is still no tool to Jailbreak 4.1. Hopefully, GreenPois0n with new bootrom exploit will aid us in jailbreaking 4.1 iOS. It is highly recommended to try this method if you have saved SHSH Blobs on a jailbroken firmware otherwise stay away.

1. Download TinyUmbrella 4.1.3 and close iTunes.
2. Execute TinyUmbrella  and “Start TSS Servers”.
3. Make sure that TinyUmbrella does not report any error. If it does then don’t proceed.
4. Start iTunes and Restore to iPhone 4.1 iOS. [Important: It is “Restore”]
5. Accept iPhone 4.1 iOS update and wait.
6. Once update is complete and iTunes displays 1004 or some other message, don’t panic. Return to TinyUmbrella and click “Kick Device Out of Recovery”.
7. Your iPhone 4 should have been upgraded 4.1 iOS while modem firmware should still be 01.59.00.

If you are confused about any step or does not understand what preserving baseband means, you should not try updating to iPhone 4 to 4.1 iOS. If you proceed, do it at your risk.

[Via ApplePress]

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