Update (10/05/2009): There is now another tool to downgrade your iPhone 3G’s baseband.
Finally, at last! A baseband downgrade tool for iPhone 3G. Readers who are iPhone 3G users who unexpectedly and accidentally upgraded their iPhone 3G’s baseband during the iPhone firmware 2.2.1 update will be happy to know that ModMyi (not the iPhone Dev Team) have come up with a tool that claims to downgrade your iPhone’s baseband from 02.30.03 back to 02.28.00.
While back in February, the iPhone Dev Team did specifically release a Pwnage Tool for iPhone 3G users so
I never thought of this, but it seems some iPhone users update / upgrade their iPhone’s firmware in airplane mode in order to avoid phone calls coming in and disrupting the update process. However it seems the latest iPhone firmware update version 2.2.1 doesn’t like this (it appears that the update requires cell phone signal?). What would or could happen is your iPhone will appear to be stuck or frozen for some time, subsequently a message reporting lost of connection would appear, causing the update to fail completely.
By the way, this applies to those updating directly via iTunes, so no matter whether or not you decide to jailbreak your firmware 2.2.1 after the firmware update, you need to update to 2.2.1 using iTunes anyway first. So it’s wise to be aware of your airplane mode and turn it off to avoid potentially wasting hours of sitting and waiting!
Incase you do run into the situation where you get a completely frozen or bricked iPhone because you left airplane mode on purposely for the update like you usually do, here’s the fix and how to get your iPhone unbricked and working again:
“To turn off Airplane Mode on your seemingly “bricked” iPhone, disconnect the USB cable (or undock), then slide the Emergency Call switch to reach the emergency call phone. You’ll be prompted to disable Airplane Mode. Tap “Disable”. Then press the Home button, reconnect the phone, and watch iTunes recognize/reactivate your iPhone.”
Thanks to Victor from TUAW for pointing this out over at Apple discussions board…