Please help. Can't get my unlocked S3 (GT-I9300) to completely work on AT&T with gophone sim

[vrp13]

I have an unlocked Samsung Galaxy S3 and I've been trying to get it to work on AT&T's networks using the gophone sim card but it doesn't want to stay connected. I can send text messages most of the time, but it will not allow me to make/recieve phone calls, or use data. I'm pretty sure that I have the right APN settings and I haven't changed any other settings. I called Samsung customer support (really good support) and they said that I might have to see if AT&T will re-flash my phone so it will work on their network.

Has anyone else had this problem with their unlocked S3? If so, how did you fix it? Any help is definitely appreciated!

 

[Rukbat]

Samsung is partially right. The problem could also be that your account isn't properly provisioned. (Pressing one wrong key when setting it up can do that.)

Go to your local AT&T store and ask them if they could please make sure that your account is provisioned properly. (Always approach them as if you're disturbing their normal workday and asking for a favor. You're not, but compared to some of the demands and curses they're used to, you'll seem like a nice guy and they'll want to help you if they can.) If that doesn't fix it, ask if they're a Support Center or, if not, where the nearest one is. (And hope it's not a 4 hour drive away.) Go to the support center, tell them the problems you're having and that Samsung tech support suggested that AT&T's reflashing the phone might solve the problem. If the clerk's had a good say, you're polite and you're lucky, it'll work and they won't charge you for it, since it was Samsung's suggestion.

Don't expect data to work as a matter of course, though. It depends on whether it's an AT&T unlocked phone or a TMobile unlocked phone using an AT&T SIM. If it's aTMobile phone you probably won't get 3G or 4G - just 2G data, like we used to get in the stone age. AT&T and TMobile use different frequencies for data.

 

[vrp13]

Thank you! I'll stop by tomorrow and see if they can help me. It's just a factory unlocked phone and doesn't have an AT&T or T Mobile brand. My brother ordered it off Amazon and it's also an international phone so I guess that could be part of the problem. Thanks again for your help

 

[Rukbat]

International (which works on almost all carriers in the world) or European (which doesn't work on any carrier in the US)? If you google the specs on the model number (not SE - the number, like i747), you'll see the frequencies it supports, and if it doesn't support 850/1900 (among the other ones it supports) it's not "international".