please help unlocked iphone 3gs updating issues

[eshan91210]

hi guys
i seem to have a serious problem
ok i got a unlocked iphone 3gs 16gb a1303 on t mobile it was on ios 3. something and it was not jailbroken
and i updated it to ios 4 and now phone screen says to connect to itunes and itunes says that my sim card is in valid.


can someone please help it would be greatly appreciated
if anything can some please answer these questions
Is the phone still unlocked?
how can i down grade the software?
And lets say i do downgrade it will it still ask for a vaild sim?

 

[PsstGreek]

What version of iOS 4 did you upgrade to? You have to activate your iPhone with an official sim card. Or you can use Redsn0w to jailbreak and that will hactivate the iPhone.

Once you update/restore it will always go to that screen and ask you for a sim card. Your problem isn't serious. Next time you should do a little more research before you do something.

 

[awadeee]

hi guys
i seem to have a serious problem
ok i got a unlocked iphone 3gs 16gb a1303 on t mobile it was on ios 3. something and it was not jailbroken
and i updated it to ios 4 and now phone screen says to connect to itunes and itunes says that my sim card is in valid.


can someone please help it would be greatly appreciated
if anything can some please answer these questions
Is the phone still unlocked?
how can i down grade the software?
And lets say i do downgrade it will it still ask for a vaild sim?

Your iPhone is asking you to activate it by inserting a valid SIM card. Since you updated your firmware, your baseband got changed to one that isn't unlockable. Your phone is no longer unlocked and since the phone is locked to AT&T, it doesn't see T-Mobile's SIM as valid. Even if you downgraded your firmware, the unlock affects the baseband. Your only choice, really, is to use Redsn0w to hactivate (it does this automatically), and then jailbreak and install the iPad baseband. You will lose GPS functionality and will no longer be able to restore your iPhone to stock firmware through iTunes, and will need to use custom firmware that is created by programs such as pwnagetool (mac) or sn0wbreeze (win).

Your iPhone is now hactivated so you will be past the "insert valid SIM" screen and will be able to use your phone. Go to Cydia and install ultrasn0w. You're unlocked.

P.S. Redsn0w will need an IPSW to read, and although I'm assuming you're on 4.3.3, here's a general directory of firmwares you can download.
http://www.felixbruns.de/iPod/firmware/