Using 3g software update on a 2g iphone with Tmobile

[rockdaddy99]

I unfortunately updated my 2g phone to the 3g OS but I have a tmobile sim card in the phone.
It was working fine before, but now I'm getting a 'non supported sim card' error message when I connect it to my computer and launch Itunes and the phone only works in 'emergency' mode.

Is there a fix for 3g OS on a 2g phone with tmobile?
If not, how do I downgrade or uninstall and go back to the old OS?

Thanks!

 

[joetdc]

I always use the AT&T sim then put the tmobile sim in after the unlock.
Restore and try it tha way.

 

[Savio]

You mean 3.0 firmware/OS right? Not 3G OS? Kind of two different things...
Anyways, just use a program like QuickPwn or redsn0w to activate your phone (so that you can get past the slide to emergency screen) and unlock it as well.