回答先: Sim card not recognizedNO SIM problem can happen to iPhone and iPad. It happen because the sim card is not connected to it place. This method is worked for me. And i Hope it work for All of you too. Here's the method: 1. Remove the sim card 2.Remove the Touchscreen, LCD and LCD Shield Plate. 3. Push down firmly at sim card slot. (Like pushing a button) 4. Insert the sim card, and see.