Here’s some updates about iPhone 3GS unlock downgrade task come from MuscleNerd, which will let users who stuck on baseband 5.14.02, 5.15.04 and 5.16.00 to upgrade to 6.15.00 then downgrade to 5.13.04 baseband which is already can be unlocked with the existing version of ultrasn0w.
Tags: iPhone iphone 3gs unlock
But they won’t develop a direct method to unlock 5.14.02, 5.15.04 and 5.16.00 basebands. Moreover this downgrade will fix the GPS issue which found after upgrading to iPad baseband 6.15.00.