I had a person staying with me for couple weeks. He handed me an S6 and said if I could get it working, I could keep it. I got to the activation screen and had a pop up appear saying to install a Verizon SIM. I don't have verizon. I then read online that I could press emergency and type in some numbers. Tried that and the emergency button is not working. Neither is the back button. I have wiped partition and factory reset from recovery to no avail. Anything I can do to get this working beyond the activation screen?