Help Ugrading Unlocked 3Gs on 3.1.2 to 4.0 Please

[GizmoHD]

I Have An Unlocked/Jailbroken iPhone 3Gs on 3.1.2 and would Like to upgrade my firmware to 4.0 or higher but afraid I wont be able to Unlock it again. The Guides Are Pretty useful but I'd like something more to the pint and specific for my phone and firmware. What I know now is that i need to first upgrade to 4.0 or greater using a firmware from Pwnage Tool (I Don Not Have This) and then I need to Unlock with Ultrasnow from Cydia and I should be in the clear using My SimpleMobile sim right?

 

[nebo1ss]

I Have An Unlocked/Jailbroken iPhone 3Gs on 3.1.2 and would Like to upgrade my firmware to 4.0 or higher but afraid I wont be able to Unlock it again. The Guides Are Pretty useful but I'd like something more to the pint and specific for my phone and firmware. What I know now is that i need to first upgrade to 4.0 or greater using a firmware from Pwnage Tool (I Don Not Have This) and then I need to Unlock with Ultrasnow from Cydia and I should be in the clear using My SimpleMobile sim right?

You are on the right track. You need to use pwnage tool which only runs on a mac to create a custom firmware. The custom firmware you create will already be jailbroken but will not update your baseband which at 3.1.2 is probably 5.11 or 5.12.

You can use the existing verson of pwnage tool to go all the way up to 4.2.1 and still have an untether jailbreak and an unlockable phone.

There are good tutorials on iclarify but the things to watch out for is make sure when you shift restore you select the custom firmware you create and not the original and also that you put the phone in dfu mode correctly.

best of luck if you don't have a mac borrow one.

 

[eastercat]

Doesn't the OP also need their blobs for 4.x or am I mistaken?

You are on the right track. You need to use pwnage tool which only runs on a mac to create a custom firmware. The custom firmware you create will already be jailbroken but will not update your baseband which at 3.1.2 is probably 5.11 or 5.12.

You can use the existing verson of pwnage tool to go all the way up to 4.2.1 and still have an untether jailbreak and an unlockable phone.

There are good tutorials on iclarify but the things to watch out for is make sure when you shift restore you select the custom firmware you create and not the original and also that you put the phone in dfu mode correctly.

best of luck if you don't have a mac borrow one.

 

[labman]

did you save shsh blobs or use make it easy in Cydia if not you can't go any further. I not sure you can make it easier the Iclarified or youtube has a ton of videos. if it's still complicated I just wouldn't.

 

[nebo1ss]

Doesn't the OP also need their blobs for 4.x or am I mistaken?

4.2.1 was still signing earlier today. If not he definitely needs blobs and hopefully since he is already jailbroken Cydia has been saving them for him.