HELP... invalid sim card on Galaxy S7
Hello. My daughter's phone is a Samsung Galaxy S7. When she turns it on its fine for a couple of minutes then the message "invalid SIM card" comes up after a couple of minutes it ends up locking on her so that she is not able to use the internet, calls, and messages. I did check SIM status and it keeps going from Boost to AT&T... don't know why. I have tried wiping it off with a soft cloth but they only helped for about 5 minutes. I need help.... my teenager is driving me crazy!!!!