Need Help DOWNGRADING 4.0.2 to 3.1.3/Jailbreaking

[Macfanboy89]

Hey Guys,

I need some advice with Downgrading/Jailbreak my Iphone3G before i attempt it.

I just bought another Iphone3G and need help downgrading it. The previous owner had it running on AT&T on 4.0 and had never jailbroken it. I need some help to get it running on Tmobile.

Iphone 3G
Verison 4.0.2(8A400)
Modem Firmware 05.13.04
Using a MacBook have Itunes 10.1

Would I be able to just follow the guide posted on Modmyi to downgrade my phone? or Would my attempt to do that with 05.13.04 firmware brick my phone? Just need some pointers on where to start and what to do before i F*ck it all up.

How to Jailbreak 3.1.3 iPhone 3G & iPod Touch 1G/2G Windows & OS X


Help me out guys =]
Thank You

[Simon]

You can use that guide. Only difference will be when restoring to 3.1.3 you will get a 1015 error. Just use tiny umbrella to kick out of recovery when you do.

[Macfanboy89]

Don't i need to have save my Firmware previously to use Tiny Umbrella?

[Simon]

Not with iPhone 3G. Dont need SHSH for 3.1.3 for that.

[Macfanboy89]

Thank You.. Gonna attempt it now
Wish me luck lol

[Simon]

Good luck

[Macfanboy89]

I went thru Redsn0w with 3.1.2 ipsw after the phone restarted I'm still at 4.0.2 as if nothing every happened....

What did i do wrong?

[Simon]

Try running it again in windows xp sp2 compatibility mode.

[Macfanboy89]

what does that mean?

I have everyone on my Mac.. does this mean i need to do everything on WindowsXP?

[Simon]

Nope, sorry. Thats just for windows vista and 7 users. It should work fine on a Mac. Try rebooting and doing it again. If still nothing you can try it on another computer or you can use jailbreakme.com to jailbreak.

[Macfanboy89]

its still now working...

IDK if this matters but everytime it restarts I get prompt by a msg that says...

"Waiting for Activation" "This may take sometime"

How does jailbreakme.com work? Do i just plug it into safari?

problem still exist and i try to do jailbreakme.com but it said my phone is too new.

My phone is currently running on 4.0.2 and in order to use jailbreakme.com i nneed 4.0.1 or lower.

Is there anything else i can do?

[Simon]

Why are you still on 4.0.2? I thought you were downgrading to 3.1.3...

[Macfanboy89]

I want to downgrade to 3.1.3 but i am currently on 4.0.2 after doing redsn0w i am still stuck at 4.0.2. Redsn0w says it's completed and all but it as it nothing ever happened

[Simon]

Leave redsnow alone. Put the phone in dfu, then option restore to 3.1.3.

[glockfan]

I thought 3.1.3 was just an update for the iPad? I ran my 3G on 3.1.2.

[Simon]

Nope, iPad was on 3.2 when it shipped. 3.1.3 was a iPhone update.