Sim Card Invalid Error on Factory Unlocked iPhone 4S
Hello experts,
I bought 2 units of iPhone 4S from Singapore and send it to my brother and his friend in India. Apple seems to have many issues so I bought in two different stores. However, one of the iPhone has a problem on recognizing the SIM card while the other one is working fine. It is showing that the SIM card is invalid. We checked on the SIM card thinking that we may have inserted it incorrectly, but it is right. We tried another SIM card but it didn't help. Can you help me?








