if your phone fall down and you notice the screen is not working or there is a deletion on it you would have two cases.
One, you first have to know that there are two type of screen in any device outer and inner screen. Therefore, if there is a scratch on the screen that means it is the outer screen so consider replacing it. Next, if there is no scratch but the screen is just not working then there is a big chance that the inner screen is damaged. Hence, no need for replacement so just go for new phone because replacing the inner screen would cost a lot near to the price of a new device so buying a new one would be the better idea.