I had a perfectly working unlocked and jailbroken iPhone 3GS, but of course I had to go ahead and try to get iOS 5 on it. I didn't know I need to preserve my baseband while updating it, so now ultrasn0w will not unlock it for me and I'm left without a phone line.
Is there any way to unlock an iPhone 3GS with 05.16.05 baseband? If not, is there any expected change that will allow me to do so?
Best Answer
By now it is possible to down-grade your baseband - at least for the iPhone 3G and 3GS (unfortunately not 4/S) - from the iPad's 06.15 to 05.13.04 (un-lockable) thanks to the great work of the iPhone Dev Team:
See this post on their blog.