Earlier this week, the iPhone Dev-Team announced the release of updated Redsn0w that allowed iPhone3GS and iPhone3G users to downgrade their baseband from that of iPad's 6.15.00 to 5.13.04 allowing them to unlock their device using ultrasn0w and getting back the GPS for iPhone3GS users. Redsn0w worked for some but many users faced difficulties in downgrading the baseband. Even after the process completes the baseband for a majority of people was still 6.15 which indicates that Redsn0w actually din't downgrade the baseband to 5.13.04.

Many troubleshooting methods were discussed but eventually there wasn't any optimum solution available to downgrade the 6.15 baseband. Senior members of iPhone Dev-Team even suggested of performing a fresh restore and then reflashing of 6.15 baseband and then attempt to downgrade. This did not help either.

Musclenerd Confirms Redsnow Update

Musclenerd today announced on twitter that he has discovered the reason for baseband downgrade failure in many iPhone3GS. According to him, the reason for failure of baseband downgrade is because of variation in NOR chip which can be changed to handle the differences between the NOR chips. There are altogether 3 types of NOR. Two are very similar and the third one is entirely different which was left out in the Redsn0w. Lastly Musclenerd clearly mentioned that he needs a loaner iPhone3GS which he'll be getting by Thursday and once the testing is done, a redsn0w update will be pushed that will allow all iPhone3GS users to downgrade their baseband without any errors. Hopefully by the end of next week every iPhone with 6.15 baseband will be successfully downgraded.