As it was promised iPhone Dev team released new Ultrasn0w to unlock iOS 6.1 on iPhone 4, 3GS on old baseband. The method is very easy and I'll show you how to do that quick. If you use iPhone 4 baseband 04.11.08, 04.12.01 or 04.12.02 and 3GS new bootrom you can't use Ultrasn0w tool. In this case try legit IMEI unlocking service to unlock iOS 6.1 firmware. Less that a month ago third-party developers, msft.guy and zmaster, released Ultrasn0w fixer 6.1 which you can use after evasi0n jailbreak and many our visitors found useful our tutorial guide on how to use Ultrasn0w fixer 6.0. You can try these both methods. But before we start you should check the list of supported baseband.

 

Supported Ultrasn0w Fixer for iOS 6.1 Baseband

iPhone 4

• 01.59.00

iPhone 3GS

• 04.26.08
• 05.11.07
• 05.13.01
• 05.12.01o
• 06.15.00

So if you found your baseband in this list the last thing that you have to do is to update your device to iOS 6.1 preserving old baseband because if you don't do that your iPhone iOS 6.1 baseband will update to the newer version and you will not be able to unlock it. And the last thing, I promise. To complete preparation for iPhone 4, 3GS unlocking you have to jailbreak iOS 6.1 using evasi0n which is the best thing in all this. So, let's start.

How to Use Ultrasn0w Fixer to Unlock iOS 6.1

Step 1. After jailbreak you need to install Ultrasn0w 6.1 package. To perform this open Cydia => Manage => Source => Edit=> Add this repo:

http://repo.iparelhos.com

Step 2. Go to Search,  find official Ultrasn0w Fixer 6.1 and install it. Step 3. Go to Search again and install official Ultrasn0w 1.2.7. Download and Install adding this repo:

http://repo666.ultrasn0w.com

Step 4. After installation process you need to restart you iPhone. Step 5. After device will reboot wait for the signal. After you get the signal of your network your iPhone 4 and iPhone 3GS will be running Ultrasn0w fixer unlock iOS 6.1 device. Also don't forget that you can find unlock for your iPhone 4 04.12.05 baseband.