This sensor flex responds to the movements of the Stylus Pen.
If you are unable to write or draw with your pen, it means that your stylus sensor flex is damaged.
Buy a brand new one from Elitecellparts.com.
Compatible with Samsung Galaxy Note 4. Model: N910, N910M, N910F, N910S, N910C, N910A, N910V, N910P, N910R, N910T, N910W.
Covered under warranty.