Touch screen not responding

[Android Question]

Hi i have a doubt, my Samsung galaxy phone touch screen is not working. Is it due to some motherboard problem. Or is it something else . please help me with answer. because, i have two pieces of same mobile,
In one mobile - Touch is gone.
In second mobile - motherboard is gone.


So i thought of replacing the motherboard of the first mobile to the second in which touch is working.

Any help pls