Possible to roll back baseband for 3GS if I have the 4.3.3 blobs?

[nanoboy]

By accident I updated to iOS 5.0.1 forgetting that I was relying on an unlock. The good news is I have 4.3.3 and prior blobs saved, so is it possible to go backward? I believe the current baseband on my 3GS device is 5.16.05.

[iYeow]

Yes, since you have updated your Baseband , you need to change your Baseband to iPad first with redsn0w 0.9.10b3
Then downgrade using custom fw of 4.3.3 , you can use either snowbreeze 2.7.3 or even redsnow to build a N0_bb ipsw

[nanoboy]

With the latest redsn0w? Also not exactly sure what N0_bb stands for. I tried the Pwnage method where I created a 4.1 ipsw using an 3.2.2 iPad and 4.1 iPhone 3GS but the newly created custom ipsw hangs at the end and errors. I tried another set of instructions using redsn0w 9.6 and a 4.2.1 stock to open with and that hung on a black screen. Im not an expert at unlocking so are there any detailed instructions, or would this work? How to Downgrade iOS 5.0.1 to iOS 4.3.3 For Untethered Jailbreak

Additionally, once I do get back to 4.3.3 is it possible to create a custom ipsw and go to 5.0.1 using redsn0w and retaining the unlock?

[b0bab0i]

With the latest redsn0w? Also not exactly sure what N0_bb stands for. I tried the Pwnage method where I created a 4.1 ipsw using an 3.2.2 iPad and 4.1 iPhone 3GS but the newly created custom ipsw hangs at the end and errors. I tried another set of instructions using redsn0w 9.6 and a 4.2.1 stock to open with and that hung on a black screen. Im not an expert at unlocking so are there any detailed instructions, or would this work? How to Downgrade iOS 5.0.1 to iOS 4.3.3 For Untethered Jailbreak

Additionally, once I do get back to 4.3.3 is it possible to create a custom ipsw and go to 5.0.1 using redsn0w and retaining the unlock?

You can downgrade iOS version but you can never downgrade baseband.

Your only choice now is to install iPad baseband(6.15.00) in order to unlock the phone, but beware you will lose GPS functions.

[nanoboy]

Oh really? I thought that was what SHSH blobs were for.

[b0bab0i]

Oh really? I thought that was what SHSH blobs were for.

SHSH blobs are to downgrade iOS version, you can never downgrade baseband. (except on a select few 3G phones with really rare bootloader)

[nanoboy]

Oh gotcha, so I have to get the latest redsn0w and which version of iPad ipsw? I can't follow this: How to Downgrade iOS 5.0.1 to iOS 4.3.3 For Untethered Jailbreak ?

[b0bab0i]

You can do iPad baseband on 5.0.1.

Do you want the unlock on 4.3.3 or 5.0.1?

[nanoboy]

Oh wow I'd love to have the unlock on 5.0.1. Is that possible?

[b0bab0i]

Yes.

You use redsn0w 0.9.10b3 to jailbreak the phone.
After you jailbreak the phone, reuse redsn0w to install iPad BB.
After you have iPad BB installed, Open Cydia and install Ultrasn0w 1.2.5.

Your phone should be unlocked.

But i have to warn you, installing iPad BB makes you lose GPS and from now on, you have to use custom firmwares to install on the phone if you want to restore the phone.

[nanoboy]

Will try this tomorrow, do I need a file or does it auto download when install iPad BB is checked? I tried today, once having Install Cydia and iPad BB checked and it just hung, black screen and nothing happened.

[b0bab0i]

It should auto detect and tell you how to put the phone in DFU mode.

You should try installing jailbreak & iPad bb separately just in case.
After you install jailbreak, check if cydia was installed, then install iPad bb.

[nanoboy]

Gotcha, the phone is already at 5.0.1 and jailbroken. So I'll just connect again, install iPad BB and try with ultrasn0w. Thanks for everyone's help in here saved me big time.

[nanoboy]

Seems as though I'm only given the option in redsn0w 0.9.10b3 for Windows to install iPad BB when you do the first jailbreak. Install Cydia is checked and you have the option to check off Install iPad BB. Am I doing something wrong? How would i be able to jailbreak then go into redsn0w and ask it to install iPad BB?

[b0bab0i]

Hmm Open up redsn0w then hit "Extras" then choose "Select IPSW", then browse for the 5.0.1 IPSW file and choose it. It will ask you if your phone is the newboot rom or old bootrom.

After you have done that click back and go back to main screen and click jailbreak. You should now see Install iPad Baseband.