How to repair HTC Sensation XE with Beats Audio touch screen?

I have bought a HTC Sensation XE with Beats Audio and I am told apparently water got inside and cant be turn on. However when i disassemble it, saw nothing, any oxidation residue. After some normal cleaning, I assembled the phone and tried to test it, it turns ON but unfortunately the screen does not work. Now I don't know what to do and changing the screen is expensive. Is there any way to make this sort of problem out?