I just got my s4 (sgh-i337m) last week. It was originally a Rogers phone, but brand new in the box. It had never been activated when I bought it from a buddy. I inserted my MTS simcard from my Galaxy S3, and powered it on, it took some kind of carrier update and from there on it works great on MTS. Since then the only thing ive done is root it using ODIN, and the Auto-Root SGH-I337M file.
Tonight, just for the hell of it, I wanted to see what it would take to unlock it. I googled it, and found all kinds of crap, lots of it a scam, and some of it paid unlock.
Well, my wife has a Rogers sim in her iPhone 4s, I put her Rogers sim in my Galaxy4S and rebooted it.... and BAM, it booted right up and displays Rogers network. And it works! Unlocked! I made a call to my home phone, works fine. I powered down and re-inserted my MTS Sim and it booted right back up into the MTS Network. Its completely unlocked! How can this be? It was originally purchased from Rogers, meant to be used on the Rogers network. My buddy who got it just didnt want it, so he never even activated it, then sold it to me.....
what going on with this thing?