How to Preserve Your iPhone 4 Baseband on iOS 4.2.1 and Enjoy Untethered Jailbreak!


How to Preserve Your iPhone 4 Baseband on iOS 4.2.1 and Enjoy Untethered Jailbreak!

 GreenPois0n RC5 released today and people are going crazy, trying to Jailbreak an Unlocked iPhone 4.

But what they don’t know is that if they update to iOS 4.2.1 they will lose the unlock and there is no unlock for iPhone 4 or the baseband 2.10.04 / 3.10.01. So this is just to remind you all that please do not update your Unlocked iPhone 4 to iOS 4.2.1 just for the sake of GreenPois0n RC5 Untethered Jailbreak.

So, to enjoy iOS 4.2.1 and the untethered Jailbreak using GreenPois0n RC5 you have to preserve your current baseband (1.59.00). Thanks to TinyUmbrella you can do that now. Here is a complete guide for you to keep your 1.59.00 baseband which is unlockable by Ultrasn0w.

Preserve iPhone 4 Baseband 1.59.00 using TinyUmbrella


[ Step 1 ]
Download TinyUmbrella for MAC or WIN

[ Step 2 ]
Install and Run TinyUmbrella and connect your iPhone 4. Plug in your device and save SHSH (make sure 4.2.1 SHSH were saved, if you can’t see iOS 4.2.1 SHSH or if you are unable to save your SHSH, please don’t bother continuing)

[ Step 3 ]
From the screen hit “Start TSS server”. Keep TinyUmbrella running do not close it and head over to iTunes.

[ Step 4 ]
On iTunes screen click on your iPhone 4 from the left sidebar. You will notice the “Update and Restore“ buttons. “Hold Shift and Click on Restore” if you are on Windows. “Hold Option key and Click on Restore” if you are on a MAC. Once you click the button you will be asked for iOS 4.2.1 firmware file. Locate your file and proceed. iTunes will recognize and install the iOS 4.2.1 on your iPhone 4. Make sure TinyUmbrella is working in the background.

[ Step 5 ]
You will be greeted with a error 1013 message, its normal stop freaking out… Press ok for the error and head over to TinyUmbrella and hit the “Exit Recovery” button.

[ Step 6 ]
You iPhone 4 should restart after the Exit recovery button and you should be on iOS 4.2.1 and your Modem Firmware should read 1.59.00. Go to Settings > General > About to confirm.

[ Step 7 ]
So once you are done with all this, here is a guide to Jailbreak your iPhone 4 using GreenPois0n RC5 and follow the next step as well.

[ Unlock iPhone 4 ]
To unlock iPhone 4 after the iOS 4.2.1 Jailbreak in last step you have to install Ultrasn0w. Here is a guide on how to Unlock iPhone 4 using Ultrasn0w.

That’s it you should be on your old baseband with new Untethered iOS 4.2.1 Jailbreak and in a complete Unlock state. You just have to make sure that when you restore iOS 4.2.1 the TinyUmbrella should be running in the background with TSS server on it running as well.

Here is how the creator of TinyUmbrella puts the whole procedure:

Start TinyUmbrella->Start TSS Server->Start iTunes->Plug Phone->Restore 4.2.1->Error 1013->DFU->GP->

If you get a 16XX error then try entering DFU and go to step 5.

If your restore does NOT end in a 1013, it means your baseband was updated. This is likely because you did not have the TSS server running OR you updated without TinyUmbrella OR you are working with a device OTHER than iPhone 4.