Downgrade iPhone 3Gs baseband from 06.15.00 to 05.13.04.
- June 23rd, 2012
- Posted in Documentation
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I suppose the first question is why downgrade the baseband now? Well, I got AT&T to unlock my 06.15.00 baseband 3Gs when it was announced that they would if you phone was no longer under contract. The only reason anybody installed the iPad (06.15.00) baseband was to unlock their phone. Since, it was no longer needed I wanted to be able to update my phone without having to use redsn0w to install a custom ISPW each time.
Software used:
Redsn0w 0.9.14b1.zip
iPhone2,1_5.1_9B176_Restore.ipsw
Download redsn0w 0.9.14b1.
Unzip redsn0w.
Download the version of IOS currently running on your device. 5.1 in my case.
Launch redsn0w.
Select Extras.
Click Select ISPW..
Navigate to the downloaded ISPW for your version.
Click Back.
Select Jailbreak.
If already jailbroken, uncheck Install Cydia and select Downgrade from iPad baseband.
Ensure that the phone is connected to your computer, and put it in DFU mode or hit Next and follow the prompts on the next screen. It might take you a few times to get the timing right.
Redsn0w will begin fetching baseband files.
The phone will reboot and you will get a message in redsn0w stating that the rest of the process takes place on your device.
On your phone, you will see several message on your phone relating to disk checks and then the familiar running pineapple on screen. Be patient.
Your phone will reboot with the downgraded baseband.
Now, if you want to go back to a completely stock installation, you will need to restore the most currently supported version of IOS (5.1.1 for the 3Gs), after putting the phone back into DFU mode.
Thanks , this is very timely for me. I have a 3gs on 5.1.1. with 6.15.00 new bootrom jailbroken and unlocked by redsnow/ultrasnow. ATT has agrred to unlock my phone but I have not been able to downgrade the bb after many tries. I understand there will be a fix for this. Meantimne, I did try to factory restore. It seemed to work but I wound up the same bb with no indication from ATT that phone was unlocked. My question is do I have to be on the downgraded bb to have the ATT restore/unlock go through?
@Mike
No, you do not have to be on the downgraded baseband to get the “Congratulations, your phone is unlocked.” message in iTunes. I had my 06.15.00 baseband phone unlocked by ATT/Apple, and got the same message using the procedure I posted in http://jim-zimmerman.com/?p=736.
Thanks, I’ll try it.
Thanks again, it worked!
Can you please let me know that after downgrade basband your iphone still service network or it need restore from itunes
thanks
@asees
You shouldn’t have to restore from iTunes. But you should defiantly back it up before you downgrade the baseband just in case.
i downgrade baseband after some problem first it stuck at boot logo after downgrade then i do redowngrade but give error to turn off by pressing power button slide off to turn off and then i decided to restore by preserving baseband then i do custom restore after that my iphone has 05.13.04 baseband on 5.1.1 and start serving carrier , now what i do or do nothing.
thanks…..
@asees
If you got the 05.13.04 baseband, you are done. You should be good to go for IOS6 this week.
when the redsnow completes the whole process,my iphone say turn ur phone into normal mode nd run redsnow again..
i hv iphone 3gs 5.1.1 and BB is 6.15.00
plzzzzzz help me
@ryan
This sounds like you are not getting the phone in DFU mode, which can take a few attempts. Also, make sure you use the exact same version of Redsn0w documented.