Why can't I send a text message when the cell phone signal is full?

You can call, but you can't send. Please turn off and restart your phone, or try again in another place. Is it impossible to send a text message to only one person? Maybe it's the other person's problem. You can try sending text messages to other people. If you can't send it to others, you can only call customer service to ask. The signal is full, indicating that the mobile phone is in normal condition, and you can make a phone call, but you can't send a text message. Maybe the number you sent the text message is incorrect. You can reset it to see if it works, or your mobile phone is restricted. The SMS function can be cancelled in the mobile phone settings. If all this is done, it can be solved by calling the operator's manual service.