Earlier, along with Ultrasn0w 1.2, the Dev Team released a special edition of PwnageTool ( version 4.1.3 ) to update the baseband to 06.15.00. This was done as the Ultrasn0w 1.2 unlock tool would work only in this baseband. But PwnageTool was only for Mac OS X. But later they released redsn0w 0.9.6 beta 5 for both Windows and Mac OS X as they promised. And this redsn0w version is much easier than the PwnageTool 4.1.3.

Redsn0w 0.9.6 b5

Dev Team has also mentioned the following :

  1. There is no way to come back down from 06.15, and there’s no hiding the baseband version from Apple.  You’ll be voiding your warranty in a very obvious way.
  2. If some future baseband comes out with a critical fix, you won’t be able to update to it if it remains down in the 05.xx sequence (then again, you wouldn’t update to it if you wanted to keep your unlock anyway).
  3. Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail).  You’ll need to only restore to custom IPSWs (then again, if you’re unlocker you should already be doing that).

NOTE : Require iPhone 3G / 3GS.

NOTE : Follow this guide only if you are on an unlock. If you don’t, then go for this guide.

Here are the steps to update to 06.15.00 baseband using Redsn0w on Windows and Mac OS X.

1. Download iOS 4.2.1 IPSW for iPhone 3G / 3GS and update to it using iTunes.

2. Download Redsn0w 0.9.6 b5.

3. Start Redsn0w and browse to the iOS 4.2.1 IPSW file.

Jailbreak iOS 4.2.1

4. After Redsn0w identifies the IPSW, click ” Next “.

Update to 06.15.00 Baseband

5. Now choose the ” Install Cydia ” and ” Install iPad baseband ” options and click ” Next “.

Update to 06.15.00 Baseband

6. Accept the warning by clicking ” Yes “.

7. Now switch off your device but keep plugged in to the computer and click ” Next “.

8. Now go into recovery mode by pressing the power and buttons for 10 seconds and then release the power button, but keep holding the home button until the iOS 4.2.1 jailbreak process begins.

Update to 06.15.00 Baseband

9. Wait till Redsn0w finish the iOS 4.2.1 jailbreak process.

That’s it! After doing this, you could unlock your iPhone 3G / 3GS using this guide.

Stay tuned to Tips Needed for more newss an guides!