I wanted to share a solution from spending a few hours with a friend's iPhone yesterday. The solution addresses problems with unlocking 06.15.00 baseband following an iOS upgrade/downgrade. From my research, it appears this has affected a handful of people who have updated their baseband to 06.15.00 so I thought the solution might be helpful.
Short version:
1) The 06.15.00 baseband may be adversely affected with restoring to a different iOS, preventing an unlock from being successful. (I would think creating custom IPSWs for upgrade/downgrade could avoid this issue).
2) The solution was to reflash the 06.15.00 baseband with RedSn0w version 0.9.6rc17
TLDR version:
A friend has an iPhone 3gs which we flashed to 06.15.00 baseband about a year ago, so the phone could be unlocked. He has used the phone without problem on T-mobile for the past year and is on iOS 4.1 For some unknown reason, his iPhone recently (within the last week) lost the ability to list available wifi networks and he was unable to connect to any (a big drawback when you consider the phone has to use the Edge network, 3G is not an option with the iPhone and T-mobile). I spent a moderate amount of time trying to troubleshoot the wifi detection, but to no avail (that is for a different thread).
Since the jailbreak for 5.1.1 recently released, I suggested we could restore to 5.1.1 -> j/b -> unlock. Since the phone was on 06.15.00, I knew the baseband would not be updated, so I didn't worry about creating custom IPSWs etc (didn't think it would be necessary, now I realize I probably could have avoided all of this if I just created a custom IPSW which should leave the baseband untouched).
Following the restore, the iPhone detected available networks (w00t! I didn't think it would work, I really thought it was a wifi antenna problem within the phone). I could NOT for the life of me get the iPhone to unlock with Ultrasn0w. After a lot of trial/error/reinstalling/rebooting etc I was unsuccessful. So, I restored the iPhone BACK to iOS 4.1 and STILL could not get it unlocked!
After more researching, I found another poster who had a similar problem. It was suggested to him his baseband needed to be reflashed to solve the unlock problem. I then had to spend some time identifying the correct version of RedSn0w which would allow me to reflash the baseband with 06.15.00 while on iOS 4.1 After some trial and error, redsn0w_win_0.9.6rc17 was the ticket! You can find archived Redsn0w distributions here: https://sites.google.com/a/iphone-dev.com/files/home/
Once I was able to reflash the baseband, I was able to unlock the iPhone. In fact, I am very tempted to restore to 5.1.1 then reflash the baseband, I think it would work.
Short version:
1) The 06.15.00 baseband may be adversely affected with restoring to a different iOS, preventing an unlock from being successful. (I would think creating custom IPSWs for upgrade/downgrade could avoid this issue).
2) The solution was to reflash the 06.15.00 baseband with RedSn0w version 0.9.6rc17
TLDR version:
A friend has an iPhone 3gs which we flashed to 06.15.00 baseband about a year ago, so the phone could be unlocked. He has used the phone without problem on T-mobile for the past year and is on iOS 4.1 For some unknown reason, his iPhone recently (within the last week) lost the ability to list available wifi networks and he was unable to connect to any (a big drawback when you consider the phone has to use the Edge network, 3G is not an option with the iPhone and T-mobile). I spent a moderate amount of time trying to troubleshoot the wifi detection, but to no avail (that is for a different thread).
Since the jailbreak for 5.1.1 recently released, I suggested we could restore to 5.1.1 -> j/b -> unlock. Since the phone was on 06.15.00, I knew the baseband would not be updated, so I didn't worry about creating custom IPSWs etc (didn't think it would be necessary, now I realize I probably could have avoided all of this if I just created a custom IPSW which should leave the baseband untouched).
Following the restore, the iPhone detected available networks (w00t! I didn't think it would work, I really thought it was a wifi antenna problem within the phone). I could NOT for the life of me get the iPhone to unlock with Ultrasn0w. After a lot of trial/error/reinstalling/rebooting etc I was unsuccessful. So, I restored the iPhone BACK to iOS 4.1 and STILL could not get it unlocked!
After more researching, I found another poster who had a similar problem. It was suggested to him his baseband needed to be reflashed to solve the unlock problem. I then had to spend some time identifying the correct version of RedSn0w which would allow me to reflash the baseband with 06.15.00 while on iOS 4.1 After some trial and error, redsn0w_win_0.9.6rc17 was the ticket! You can find archived Redsn0w distributions here: https://sites.google.com/a/iphone-dev.com/files/home/
Once I was able to reflash the baseband, I was able to unlock the iPhone. In fact, I am very tempted to restore to 5.1.1 then reflash the baseband, I think it would work.
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