3G 3.1.3(7E18)/05.12.01, 4.2.1 wanted, no unlock, but JB & downgrade possibility needed

[kecskesadam]

Hi guys,


I ask this just not to ask it too late.

Friend has this 3G on 3.1.3 (JB with spirit), with the 05.12.01 BB.
He'd like to go to 4.2.1. and JB it.
There's NO NEED to unlock, but he'd like to be able to downgrade from 4.2.1 to 4.1 or even back to 3.1.3, just in case.

What is the method here? I thought:

Tinyumbrella, save shsh
Update iTunes
Update iphone 3G with iTunes to 4.2.1
JB with redsn0w 0.9.6rc8


Is it good like this? Did I miss anything?

(Bonus question: What should we do to be able to have unlock on 4.2.1?)

Thank you in advance!

[Simon]

if unlock is not needed then your steps are correct.
If you want to keep ability to unlock then you need to make a custom 4.2.1 with no baseband update in it with pwnage tool and restore to that.

[kecskesadam]

No unlock solution on windows then?...

Thank you for your responses!

[Simon]

Not for 4.2.1 yet no

[iymdom777]

I have a question.
If i had a 3G 3.1.3(7E18)/05.12.01, and i wanted to JB and unlock it, without the need to do a restore or to go back, can i do the following: ?

Tinyumbrella, save shsh
Update iphone 3G with iTunes to 4.2.1
JB with redsn0w 0.9.6b5 using iPhone1,2_4.2.1_8C148_Restore.ipsw
unlock with redsn0w 0.9.6b5 using the same file ipsw (ipad baseband 4.2.1 / 06.15.00)

Thanks!

[Simon]

I have a question.
If i had a 3G 3.1.3(7E18)/05.12.01, and i wanted to JB and unlock it, without the need to do a restore or to go back, can i do the following: ?

Tinyumbrella, save shsh
Update iphone 3G with iTunes to 4.2.1
JB with redsn0w 0.9.6b5 using iPhone1,2_4.2.1_8C148_Restore.ipsw
unlock with redsn0w 0.9.6b5 using the same file ipsw (ipad baseband 4.2.1 / 06.15.00)

Thanks!

No do not do that method. Updating to 4.2.1 will be a restore, you cannot update directly to it.
Most importantly though you already have a unlockable baseband with 5.12.01. DO NOT LOSE THAT. Do not restore to 4.1 or 4.2.1 regular firmware and do not install the ipad baseband. You dont need it.

You have two options.

1: Stay on 3.1.3, use jailbreakme.com to jailbreak and install ultrasnow to unlock.
2: Make a custom 4.2.1 firmware with pwnage tool or snowbreeze and restore to that in itunes to preserve your baseband. Then install ultrasnow to unlock.

Option 1 is by far the easier of the two and 3.1.3 runs much better on a iPhone 3G anyway. 4.2.1 will slow it down some.

Oh, and you have no need for tiny umbrella with a iPhone 3G.

[iymdom777]

Thank you Simon for the info.
have a Happy 2012!

[Simon]

You too