Why does my touch screen become unresponsive to touches?
My iPhone 4, a refurbished model A1332, becomes unresponsive to display screen touches. When launching an app with a touch, it seems to work for a few seconds, then the display freezes up and becomes completely unresponsive. Pressing the home button results in the closing the app or displaying the "slide to unlock" screen, but the slide on this screen is unresponsive, and so is the camera button. I took the phone with me for an exercise walk, and thought to start the stopwatch app, and to my surprise this worked great for the entire time it was working. I was able to time segments of my walk with the lap button, so the display was indeed responding to touches with that app. Perhaps because it had to be updated frequently: every tenth of a second. The phone fell off my coffee table once, just a few minutes ago, but it was having this problem with the display freezing up before then.
From reading other questions and answers here, I am almost certain that I need to replace the entire display assembly. Are there any other parts I need to replace to completely repair the problem?