A SIM card, or subscriber identity module, is a small card in your cellphone that lets you place phone calls, send text messages, and more.

If your SIM card is not showing a signal even after multiple fixes, then you need to try these solutions: If your SIM is old, bent, or frequently loses connection, it’s better to get a replacement SIM ...

If you can't make a call or if you see an error message that your phone's SIM card is not working, there are several ways to ...

These two ways of connecting your phone to a cellular network are very different. We tell you about each and how you can switch from one to another. I started my career with CNET all the way back in ...

The agency says it found a network of some 300 servers and 100,000 SIM cards—enough to knock out cell service in the NYC area ...