iPhone with any at&t sim card?

[nikhiljoshi]

I have recently purchased an iphone 3G with updated baseband which was previously used with AT&T. I have jailbroken the phone with custom 3.1 firmware but haven't unlocked it yet.

I heard that 3G supports any sim card from at&t if it was previously registered with at&t. I tried using another at&t sim card but it did not work.

Please atleast let me know whether it was supposed to work or not with any at&t sim card or it's because of the updated baseband and FW?

[StealthBravo]

iPhone should work with most newer sim cards

[nikhiljoshi]

What do you mean by newer sim cards? Sorry but I didn't get the answer.

How do I know whether the sim that I tried is newer??

[StealthBravo]

Some of the older sims +3 years ago do not seem to work. Most of the time it will work with your sim

[joecef]

would it matter if you used activated or unactivated custom firmware?

[nikhiljoshi]

I have used the both and tried using 2-3 ATT sim cards but it doesnt detect any signal. Is their any unlocking for the sim also that we have to do??
I mean are the at&t sim cards locked for the device that we get it for??

[CaptainChaos]

Simcards are not locked to specific devices. You should be able to stick your sim in any AT&T phone and have it work. I swap between my iPhone and a Sony phone when my iPhone gives me issues.

[yeshess]

I have the same problems with the sim card. Nothing at all. Before I jailbroke it, the sim was workig fine. I put it in my VU and it works fine. However the iphone cant connect. It shows a tiny bar and nothing else.

I'm using a iphone 3g with version 3.1 (7C144) carrier at&t 5.0

ANy help would be greatly appreciated. Back to my search. Hope I find something.