All of a sudden message saying""unauthorized sim" and nothing works
Same thing happened to my phone when I accidentally dropped it on the floor. All I had to do was to check my SIM card and re-insert it properly to the SIM card slot. It got removed a bit from the slot probably due to the drop.
If that doesn't work, you may need to get a new SIM card. Request one from Virgin. They should give you a new SIM card that has the same number as your old one.