If you trouble downgrading your iPhone 3GS’ baseband from 06:15:00 using Redsn0w 0.9.14b1 released by iPhone Dev team few days back then we’ve an update for you.
MuscleNerd from the iPhone Dev team has tweeted that he may have found a solution to fix the problem.
ok, figured out why some 3GS phones refuse the iPad downgrade! Can fix that after receiving another loaner (delivery expected on Thurs)
He goes on to explain why Redsn0w 0.9.14b1 is not working for some iPhone 3GS users:
it’s due to variations in the NOR chip. The payload can be changed to handle the differences but I need one in hand to test
He has also confirmed that he will update Redsn0w to support all three variations of the NOR chip:
RCE of Apple’s 3GS flashers shows 3 types (2 very similar, but this 3rd is pretty different). Will change redsn0w to support all 3
He has recommended iPhone 3GS users who have problems downgrading to wait for the Redsn0w update (Redsn0w 0.9.14b2), which should be released next week.