T-mobile to AT&T

[FrozenFlames450]

Hey all,
Due to an upcoming move, I need to switch my service provider from T-mobile to AT&T, and am having a bit of confusion. I've read quite a few different posts that all seem to say slightly different things. So here's whats going on with me:

I have one of the first 16gb iphones (which was OTB 1.1.3 and 4.6BL and 04.03.13_G, i believe) and I used iPlus to jailbreak/activate/unlock the phone.
I am currently running 1.1.4 with 3.9FakeBlank and firmware 04.04.05_G.
This all works fine and dandy on T-Mobile. However, I need to make my phone back as it was when I got it so that I can take it in to the AT&T store so they can add me on as another member of a preexisting family plan and I can use AT&T service. (and of course ditch the T-mobile plan, of which my contract expires in like a week)

Can someone please help me get from my current settings to a "virginized" version of the settings so that I can take it in to an AT&T store and they won't freak out...
Thanks!

[StrictlyBusiness]

Put it in the microwave for like 10 sec and bring it in demand a 3g iphone

say it could've burned your damn house down

[hiflyer]

Just DFU restore back to 1.1.4 and setup as New.

[FrozenFlames450]

If I just dfu restore it to a clean 1.1.4, is the fact that it has previously been jailbroken/unlocked/activated and that the 3.9fakeblank is still on there going to have an effect on AT&T's decision to b*tch at me or not?

[landru64]

i just did a similar thing- i had a defective iphone (part of the screen stopped sensing touch) and it had been unlocked/jailbroken with iplus. it was tough to find the answer, but i believe those who say it just needs a restore are missing the issue of the bootloader. what i did and was told to do was to erase the baseband and then restore to 1.1.4 using itunes. i erased the baseband using ziphone 3.0 which has a graphical user interface and allows you just to erase the baseband. it all worked well and the apple store did not find any problems with the defective phone

this is where i got my information. i was not able to get eziphone to erase the baseband so i just used the latest version of ziphone.
Unlock any iPhone any network. Complete Best Guide. 1.1.4 UK US 3g 8gb 16gb. ziphone youtube games | WebiSee.com - digital life for everyone

[Poseidon79]

Use iPlus or iLiberty to upgrade your bootloader from 3.9FB to 4.6. Then you can restore and take back for warranty.

[m3thodandr3d]

If you don't activate it on AT&T, you can almost forget about your warranty. Hope everything turns out alright.

[rstuvwxyz]

I would activate with a popular phone that would be easy to resell, go home and call customer service to have them make the changes to your account tellin them u previously had a prepaid sim. it might take a couple of calls but remind them your only other option would to be cancelling within the 15 days to receive a full refund. i believe at this point they would be much more worried about you trying to upgrade to the 3g model for free than not wanting to give your sim card a lil luvin.