1F xx 2700/ 6f18
no sim card instaled, this message appears in my iphone4, what should i do?
iPhone 4, fail
You know the exact same thing happened to me yesterday... I had my phone about a week and no issues, then all of the sudden I wake up and it said "No Sim". I took it in and out a few times with no luck, then I went to the AT&T store and got a new SIM - went through the activation agian (which only took like 2 mins) and it was fixed. Maybe the heat from the phone damages the sim card or something. You should get a new sim and it should be fine.