How to Downgrade iPhone 3GS Baseband 05.16.05 / 05.12.07 / 05.13.04 / 05.14.02 / 05.15.04 / 05.16.02 / 06.15.00

On August 6, 2011, in Downgrade, by admin

The downgrade iphone 3G is used to fix the problem after update of the GPS baseband iPad 06.15.00,
or to block the release of the operator of the iPhone 3G.
A good system if you backup by 4.1 SHSH is:

1.Download 4.1 stock firmware from apple.
2.Restore 4.1 directly using iTunes.
3.Backup 4.1 SHSH using TinyUmbella.
4.Make a custom firmware using PwnageTool_4.1.3.
5.Restore 4.1 custom firmware using iTunes.
6.”Exit Recovery” using TinyUmbella if need.

PwnageTool_4.1.3

TinyUmbella 5.00.07
http://cache.firmwareumbrella.com/do…la-5.00.07.pkg

iPhone 4.1 stock firmware
http://appldnld.apple.com/iPhone4/06…7_Restore.ipsw

If you have not saved SHSH.
I found this video on youtube.