I got a Galaxy S3 recently from my cousin. He had rooted it, got an unauthorized software warning, panicked, and flashed back to stock. After doing so, he was unable to get the phone's cellular radio to work properly. So he sent it to me to work on. I tried re-flashing the OS using Odin, and I also flashed the radios, but no matter what I do, when I put in my SIM, it still says I'm roaming. I checked on My Verizon and it says that the phone is activated. Any idea how to fix this (hopefully without taking it to Verizon)?