GT-N7100 does not recognize specific SIM card
My mom has a factory unlocked international GT-N7100. She came to the US to visit me and I got her a line from Mint Mobile, a subsidiary of T-Mobile US, which I also use. When I plugged the new SIM in her phone the phone gave the "No SIM card" error, but interestingly it still shows bars and reads a signal. I thought the SIM card itself is faulty. I inserted the SIM in my phone and it worked flawlessly, I was even able to send texts and make calls from it. Then I thought although her SIM was working previously, maybe I broke the phone's SIM reader in the process, but I inserted my Vodafone card to it and it roamed to T-Mobile, so I know that the phone can read SIM cards and it can connect to the T-Mobile network.
Long story short, phone accepts other SIM cards and connects to the same network, SIM card works with other phones, but this specific combination does not work. Anyone have an idea why that might happen and how to solve this problem?