I went to "settings" earlier and clicked on the "check for updates" button. It brought up one and I told it to install. It did and afterwards I was trying to text someone and it kept glitching and taking me to my home screen. I turned it off and tried to turn it back on, but when I did the start up sequence took abnormally long and after the Galaxy logo went away nothing happened. There's a black screen with nothing on it and none of the buttons work. I've taken the battery out and turned it on again but it doesn't help.