Unicom card can't send text messages on iphone5s? I can send this Unicom card message on other mobile phones. Unable to set the 5s mobile phone service center number.

IPhone can't send text messages Troubleshooting: 1. Make sure the signal is normal and turn off the flight mode. 2. Check whether the SIM card status is normal. 3. Check whether the send key is bright and clickable. 4. If you can't click Send after entering the text, the "Send" key is still gray. Please turn off "Show Subject Bar" in Settings > SMS >. 5. If you send text messages to multiple people and manually enter numbers, please make sure to use line breaks instead of spaces to separate each number. 6. If you can receive or not send SMS, after the above problems are eliminated, you can use the internal command to edit the SMS center number: set the SMS center number: dial *5005*7672*+86 SMS center number # with iPhone; Delete SMS center number: dial ##5005*7672# with iPhone. Inquire about the set SMS center number: dial *#5005*7672# with iPhone. When using the internal command, first use the delete command, and then set the SMS center number.