Lenovo TD30t, the mobile phone sent by the mobile phone bill, suddenly can't send a short message and can't receive it. What happened?

Is it possible that something was accidentally changed in the settings? I changed the network settings before, but even if I changed them back, I went back to the factory settings. As a result, when there is a signal, I can't make a phone call or send or receive a text message, so I'd better brush it later.

Find the corresponding version of the brush on the Internet, brush it and try it, which is equivalent to ghost restoring that nature and should be able to save it.

Brush machine is very complicated. If not, go to Lenovo for after-sales solution. This is not a hardware problem, there should be no cost.