How to delete SMS when the key is invalid?

If there is a problem with the phone keys, we suggest you try:

1. If you can't use the Back button to return to the previous interface or exit when running a program, it is recommended to click the HOME button to return to the standby interface and try to re-enter the program.

2. Turn off the phone and restart it.

3. If the back button, menu button, recent application button and HOME button of the mobile phone can't be used, it is recommended to uninstall the recently installed software and delete it as much as possible.

4. If not, please back up the data (contacts, pictures, etc. ) and restore it to the factory settings.

If the problem persists, there may be something wrong with the internal hardware. I suggest you take the three-guarantee certificate of your mobile phone and send it to the nearest Samsung service center for engineers to check the machine.