Why does my just-unlocked AT&T Galaxy S3 disconnect right after you hit 'Send'?

[AC Question]

Just-Unlocked AT&T Galaxy S3 Disconnects Right After You Hit 'Send'

I unlocked my AT&T Samsung Galaxy S3 with a code purchased online. I put in a SIM card bought for my wife to use in Mexico, with a Mexico phone number, but that can roam in USA and Canada. I'm testing it right now in the USA, before she takes it to Mexico.

The display confirms roaming on AT&T Telcel, and it gets text messages. But it won't send text messages, and it won't make or receive calls. When I hit send, the call looks as if it's being placed, for about two seconds, then the phone disconnects.

I'm not sure if it's a Mexico SIM issue or an issue with some kind of roaming blocking. I've searched every menu to make sure roaming has permission on this phone. Will this clear up when the phone gets to Mexico? I don't think it will.

 

[itguyjax8430]

Re: Just-Unlocked AT&T Galaxy S3 Disconnects Right After You Hit 'Send'

I unlocked my AT&T Samsung Galaxy S3 with a code purchased online. I put in a SIM card bought for my wife to use in Mexico, with a Mexico phone number, but that can roam in USA and Canada. I'm testing it right now in the USA, before she takes it to Mexico.

The display confirms roaming on AT&T Telcel, and it gets text messages. But it won't send text messages, and it won't make or receive calls. When I hit send, the call looks as if it's being placed, for about two seconds, then the phone disconnects.

I'm not sure if it's a Mexico SIM issue or an issue with some kind of roaming blocking. I've searched every menu to make sure roaming has permission on this phone. Will this clear up when the phone gets to Mexico? I don't think it will.

Welcome to Android Central!

It could be come kind of roaming block from the Mexican Telecom. Did you make sure that the plan you got for it included international roaming?