Hi all! I'm new to this forum. I got my S3 last month and everything went fine. Then a week ago, I can't call phone and show sim problem. but that sims work fine on other phones. So I check my IMEI by *#06# , that shows IMEI null. I haven't backup it (and don't know how to do.) So now it work as an ipod without phone function. Please help me how to do???? Thanks!