Why can't iphone4s make a phone call? The screen shows "China Mobile", but calling and texting always fails, and I can't send it out!

I don't know if you are in the same situation as me. I'll send a text message to 90% and then make a phone call. I tried to call my home phone and found that it would ring, but there was no sound and my mobile phone didn't respond. Then I press cancel to call the screen and it gets stuck.

I searched the internet and speculated that it was related to cellular data, so I opened the cellular data with a grain of salt. As a result, the text message came in and the mobile phone was able to make calls. You can try. . I have only practiced this method once, waiting for more people to verify it.