Help Unlocked S2 not working in USA

[Lynne Connolly]

I inherited the S2 from my son when he upgraded. He was using it on Vodaphone, but it was unlocked. I put my TalkMobile UK contract SIM in it, and it works fine. No problems.
Then I went to the USA. Over there, I use a monthly tariff AT&T SIM. It was the first time I'd taken the Galaxy S2, so I took my old phone, a Galaxy Ace, just in case.
Just as well I did. The S2 refused to take the AT&T SIM. It said there was no SIM inserted. The SIM worked fine on the Ace, and it registered when I tested the SIM in other people's phones.
I thought this regional lockdown thing started with the S3? Is there anything I can do to get the S2 working on both sides of the Atlantic? I visit the States a fair bit, so it would be really great to find a phone that would work in both places, and not the Ace, because I really don't like that phone!

 

[ironass]

As you can see from the comparison of the International Galaxy S2, GT-i9100, and the AT&T variant, known as the Skyrocket, SGH-i777, that they are virtually identical and there should be no reason that I can think off why you should not be able to use the International on AT&T's network other than AT&T themselves who may not recognise the i9100 as network compatible. In the first instance, I would contact AT&T and explain that you wish to use the International on their network in case they need to allow its use.

 

[Lynne Connolly]

friends in the states have the same model that works. and the sim works in all the other phones I have except that one that keeps asking me to please insert sim and no sim recognised. I want it to work on both sides of the Atlantic. I guess there's no answer, then. I can't think of a reason why it won't work either. it just doesn't.