My Samsung mobile phone is a customized version of Unicom. It's okay to call and receive text messages when you change your mobile card, but your mobile phone can't send text messages.

According to your description, I suggest you try the following methods:

1. Restart the phone to see if there is a signal problem.

2. Settings-Application Manager-Swipe Screen Options (All)-Find Information-Click Enter and try to clear the data.

3. Try to replace another SIM card.

4. Check whether the mobile phone is equipped with security guards or third-party SMS software, and test it after unloading.

5. Back up mobile phone data (phone book, SMS, multimedia files, etc.). ) and restore the factory settings.

If the above method still fails, please send the equipment to Samsung Service Center, and the engineer will check the machine and deal with it.

Please click the following link to find out the specific location of Samsung Service Center:

. Samsung . com/support/service locations . ASP

Samsung knows to provide you with high-quality solutions and answer your questions attentively, hoping to get your satisfactory evaluation.