Howto: iPhone 3G - Downgrade your baseband from 2.30.03 to 2.28.00

Thanks to pH (Pedro Henrique Franceschi), it is now finally possible to via a simple tool called pHaseBanDowngrader.

You may need to downgrade your baseband to use Yellowsn0w to unlock. As you may know, YellowSn0w only works on 2.28 baseband. Previously, those of you that upgraded to 2.2.1 could not use YellowSn0w. Now you can.

Okay, here is some simple instructions about how to use it:

1. Download the .zip in the end of the post.
2. SSH into your iPhone and put the downloaded folder (phasebandowngrader) inside the folder /Applications/.
3. In MobileTerminal.app, type “login” and enter “root” as user, the default password is “alpine”.
4. Now, type “cd /Applications/phasebandowngrader && ./phasebandowngrader”. Follow the screen instructions.
5. Enjoy!

Many guys from irc.osx86.org had tested it and they are loving the downgraded iPhone. To use that tool, you need to have an iPhone with the Bootloader 5.8. If your iPhone was manufactured before September 2008, you are 5.8. If your device is 2.2.1 OOB (Out Of Box), you can’t downgrade the Baseband because you have bootloader 5.9.

Download pHaseBanDowngrader