iPhone 3G Baseband Downgrade GUI [Cydia]

WARNING: This tool is NOT a toy. Just use it if you can’t use yellowsn0w on your 2.2.1 iPhone 3G. Otherwise, DO NOT INSTALL IT JUST TO TEST! YOU HAVE BEEN WARNED!

This software is for iPhone 3G users who upgraged to 2.2.1 firmware, but still need yellowsnow unlock. Yellowsnow doesn't work with 2.2.1 firmware's 02.30.03 baseband. So we need to downgrade it to version 02.28.00, that was used in 2.2 firmware. To downgrade it you need this software, that you can install via Cydia. It is very easy to use. Just download it from Cydia (called 3G BaseBand Downgrage), open the app and click Go.

The 3G Baseband Downgrade just works on iPhones 3G with Bootloader 5.8, that can be detected using minicom. If you don’t know how to use minicom, there’s a “simple” way to know if you are 5.8 or 5.9 (but this is not 100% sure). If your iPhone was manufactured before September (2008), you are 5.8. Otherwise, you are 5.9 (that can’t be downgraded).