why doesMy Galaxy Note thinkg there is a usb device connected when infact there is not?

Some time ago bu note started randomly shoing thatthere is a usb connector connected when there is not. It also shows a message that it is disconnected seconds later... I have not ever connected anything except the charger so I am not sjre what is going on. Any help?

You may need to clear the cache partition on your phone or do a factory data reset.