Finally bit the bullet on a new iPhone 7 today. Got sim-free. When I powered it up, I had LTE and three bars. Then while going through the setup process, it drops to No Service. And it stays like that. I've tried numerous things. I've tried a hard erase and reset. I've tried turning on and off airplane mode. I've tried resetting network settings. I've even tried a sim card for a different carrier and the same thing happened. I've tried turning off VoLTE. I have latest version of iOS and carrier settings. Has anyone else had this problem? What can I do?