My phone fell on the floor and then it had some scratches on it but It

I have seen this mostly on android phones. The internal lcd has been damaged. You can still damage it without cracking the glass. If you put the phone under a lamp or some type of light and rotate it a bit, youll probably see a black line or some type of imperfection that will indicate the lcd being damaged. The only fix for this, unfortunately, is to replace the screen.