Phone suddenly showing "No SIM" or "Invalid SIM"? Don't panic, there are a few quick checks that can get you reconnected fast.

So you’ve chosen Ultra Mobile as your carrier. Great choice! But before you start enjoying those international calling features or high-speed data, you need to install your SIM card. Don’t worry; ...

Once you’ve activated your iPhone with your carrier, it should continue to work on the cellular network without any problems as long as you’re within range of a tower. Nevertheless, the vagaries of ...

Today we bring you three #GalaxyS7 problems that not a lot of support sites cover. SIM card problems usually occur in isolated instances so we can only provide general troubleshooting suggestions for ...