How to Downgrade Your iPhone 3GS, 3G Baseband for Unlock (Mac)

How to Downgrade Your iPhone 3GS, 3G Baseband for Unlock (Mac)

Registered users can display a profile image alongside their comment.
You can upload your photo here. If you haven't registered you can do so here
Add Comment
fubar121 - April 13, 2013 at 1:27pm
Great tutorial thank you for you hard work. How ever I can not get my 3gs to downgrade. I have tried just about every version of redsn0w with every possible firmware. currently stuck with iOS 4.1(8b117) with baseband 06.15.00 my phone is bell 3GS Model MC637C and serial 86023F0UEDG. Currently unlocked and jailbroken with redsn0w latest and ultrasn0w latest. I haave been pulling my hair out for a week now. I can reinstall the 06.15.00 with no issues and everything seems to work fine including the gps?? but when I try to downgrade redsn0w starts the exploit then crashes saying downgrade failed?? Anyone have any ideas?