In order to unlock your iPhone 3G / 3GS on iOS 4.2.1 (basebands 05.14.02 and 05.15.04) with ultrasn0w we first need to upgrade it to baseband 06.15.00 using pwnagetool or redsn0w.
To update your iPhone baseband to 06.15.00 with pwnage tool follow this tutorial.
Tethered vs Untethered
- iPhone 3G is untethered upto iOS 4.2.1
- iPhone 3GS old bootrom are untethered up to iOS 4.2.1
- iPhone 3GS new bootrom are untethered up to iOS 4.1
Required Downloads
Pwnage Tool 4.1.3 Unlock Edition (Torrent old download link not working: http://torrents.thepiratebay.org/5994102/PwnageTool_4.1.3_Unlock_Edition.dmg.5994102.TPB.torrent ) (Direct Download 1 : http://loloke.hu/PwnageTool_4.1.3_Unlock_Edition.dmg ) (Direct Download 2 : http://www.tomreinartz.com/DevTeam/PwnageTool_4.1.3_Unlock_Edition.dmg )
Upgrade iPhone to Baseband 06.15.00
1. Download all the required files and save them in a folder on your desktop
2. Launch pwnage tool, accept initial message by clicking OK. Select your iPhone 3G or 3GS option and click the blue arrow to continue
3. Select the IPSW file firmware 4.2.1 for 3G and 4.1 for 3GS that we saved on the desktop in the initial steps.
4. A popup will ask if you want the baseband to be updated or not, now we have two options:
- if the current baseband is version 05.14.02 or 05.15.04 then click yes
- if it’s not one of these two basebands, then you probably don’t need and don’t want to update your baseband, so click NO.
5. select the iPad iOS 3.2.2 file from your desktop in this step
6. Now you have to chose if you are on official carrier or unofficial.
- If you are on your official Service provider (i.e AT&T) there is no need to unlock the baseband, so you can simply click yes
- If you are on unofficial service provider (other than AT&T) check “Activate the phone” so that you can use Ultrasn0w to unlock your iPhone and click NO.
7. When asked to save the custom .ipsw file, save it in the same folder that we have on desktop. You will be needed to give your administrator password to continue the process.
8. Once the custom ipsw file has been built, Pwnage Tool will guide you through the steps on how to put your iPhone to dfu mode
9. When your iPhone has successfully entered the dfu mode, launch iTunes when pwnage tool prompts you to do so.
10. select the custom firmware by holding down alt / option key when pressing the restore button in iTunes. This will open a windows where you can look for the custom built ipsw file that we saved in the folder on the desktop
11. iTunes will then restore the jailbroken firmware 4.1 on your iPhone 3GS and 4.2.1 on 3G with baseband 06.15.00 ready to be unlocked by ultrasn0w.