IPhone 3GS IOS 4.1 and baseband 06.15.00 needs to be unjailbreaked

[avinash73]

Hi,

My iphone 3GS IOS 4.1 and baseband 06.15.00 needs to be unjailbreaked. I got it from my friend and so not sure of exact factory setting when he would have purchased it or not aware of the fact if it was factory unlocked (or unlocked by him) before reaching me. Unfortunately not aware of his whereabouts .

1. I am aware of the fact that , by going to cydia installer and then selecting remove (cydia will be gone) . Is this the right way to unjailbreak?

2. Else i can use itunes to restore it to factory setting. Now my fear is, after restoring to factory setting, will my phone might get locked again.

My basic question is how should i unjailbreak by keeping this baseband intact, so that i don't lose the unlockability feature of this phone.

Thanks
Avi

 

[waldoe]

Use reds 0w to downgrade from the iPad baseband by pointing redsnow to your firmware under extras--> select firmware. Then go back and click jailbreak. Follow te instructions and Choose only downgrade iPad baseband. Once this is complete, you can do an official iTunes restore. Sorry didn't see you wanted to keep unlock ability. After you downgrade baseband use snow breeze or redsnow to make custom firmware by pointing the program at your 4.1 firmware that you will need to download. Then use shift + restore in iTunes to restore to the custom firmware.

 

[waldoe]

Use reds 0w to downgrade from the iPad baseband by pointing redsnow to your firmware under extras--> select firmware. Then go back and click jailbreak. Follow te instructions and Choose only downgrade iPad baseband. Once this is complete, you can do an official iTunes restore

Also, if the BB is at 06.15.00 it is most likely not factory unlocked. Then again it could be but then there would be no reason for the iPad baseband.

 

[cherlloydfan1]

Downgrade BB with redsn0w
Make a custom 5.1.1 ipsw with sn0wbreeze
Go into Pwned DFU Mode
Hold shift *while* clicking restore
Choose the Custom IPSW
Let it restore.

Tada

 

[waldoe]

Custom 5.1.1 ipsw is only necessary if Avi wants to upgrade as last time I did a downgrade,(end of june) apple was still signing 4.1 for 3gs.

 

[cherlloydfan1]

Custom 5.1.1 ipsw is only necessary if Avi wants to upgrade as last time I did a downgrade,(end of june) apple was still signing 4.1 for 3gs.

True. I see your point

 

[avinash73]

Use reds 0w to downgrade from the iPad baseband by pointing redsnow to your firmware under extras--> select firmware. Then go back and click jailbreak. Follow te instructions and Choose only downgrade iPad baseband.

.

I would be pointing to following firmware - iPhone2,1_4.1_8B117_Restore.ipsw. While i do this for my iphone 3GS, will my baseband go to 05.14.02 amd if so can it be unlocked using ultrasnow

Thanks
Avi

 

[Thomasjtsi]

Unfortunately no. Once you're on the 6.15.00 BB you'll always need to restore/update w/ a Custom IPSW file. However, you CAN downgrade your 6.15.00 BB to 5.13.04... this allows you to use ultrasn0w AND restore/update w/ stock IPSW files. http://www.iphoneforums.net/forum/iphone-unlocking-69/downgrading-3g-3gs-baseband-05-13-04-a-42452/

 

[Thomasjtsi]

Custom 5.1.1 ipsw is only necessary if Avi wants to upgrade as last time I did a downgrade,(end of june) apple was still signing 4.1 for 3gs.

Apple may still be signing that specific iOS version. However, a Custom IPSW for that version needs to be created w/ "Baseband Preservation" as to not goof up the iPad Baseband it's running on.

 

[waldoe]

Apple may still be signing that specific iOS version. However, a Custom IPSW for that version needs to be created w/ "Baseband Preservation" as to not goof up the iPad Baseband it's running on.

Exactly, it is always best to preserve the BB. But the iPad baseband can be downgraded regardless of iOS version, and at the end of that BB preservation is still required for a restore or upgrade. Also, correct me if I am wrong, but doesn't snowbreeze automatically preserve baseband in every mode?

 

[Thomasjtsi]

Also, correct me if I am wrong, but doesn't snowbreeze automatically preserve baseband in every mode?

I'm not 100% sure. I always use redsn0w... but I know that sn0wbreeze has the preservation option. Perhaps one of our other Gurus can chime in w/ a ruling on that.

 

[waldoe]

I just ran snowbreeze to check and when hovering the mouse over preserve baseband mode it states that the option is for preserve baseband mode only and all other modes still preserve the baseband. But as you said (and I know may who prefer redsn0w) you have to choose that option in redsn0w.

 

[avinash73]

so now i have successfully downgraded to 05.13.04 with IOS 4.1 in my iphone. From here on, red snow is neither making a custom ipsw of 4.1 (giving message as only 4.3.3 and 5.0 + is supported) or am i able to use custom ipsw of 5.1.1 to update ios from 4.1 (as i get a message in itunes as firmware file is not supported) . so what can be my next step ahead?

 

[cherlloydfan1]

so now i have successfully downgraded to 05.13.04 with IOS 4.1 in my iphone. From here on, red snow is neither making a custom ipsw of 4.1 (giving message as only 4.3.3 and 5.0 + is supported) or am i able to use custom ipsw of 5.1.1 to update ios from 4.1 (as i get a message in itunes as firmware file is not supported) . so what can be my next step ahead?

Get redsn0w 0.9.6b6

 

[avinash73]

After getting to baseband 05.13.04, i created custom IPSW for IOS 5.1.1 with redsnow 0.9.14.b2 and then tried to update my 3GS. But in itunes am getting message as firmware file is not compatible, when i tried to select custom ipsw.