Screen unresponsive before and after repair

My iphone 5s was dropped into a pool for a few moments by a family member. It was not turned off immediately and they told me there were a few lines on the screen but not much water got in. The screen became unresponsive almost immediately. I ordered an OEM replacement screen and I replaced it myself very carefully and it comes on with every pixel working but it is unresponsive to the touch. I have the phone open and see no signs of corrosion or anything. What could be the problem?