Which parts should I replace?

My iPod Touch 3G 32GB fell in the snow and got some "big" waterdamage. The LCD Display is working strangely. AND the touchscreen isn't responding at all. The iPod Touch fell in some Snow and it got pretty wet. The back side at the top (where the Powerbutton is) even got heated and made silly sounds. Well now it's all dry and my warranty isn't there anymore since the water sensor has been activated.

I need to know what could have gone broken.

And which part is responsible for the TOUCH at the iPod Touch.

PS: I've managed to restore my iPod and it seems to be wokring, but the touchscreen isn't. I can put music on it and it plays (voice control works too).