Galaxy Note 4 - S-Pen not working on a part of a screen

[Mateusz_Obara]

So... I have second hand note 4 (and I don't have guarrancy now). Everything was fine for few months but today s-pen stopped to work in a 3/4 height half of inch strip from left to right side of screen. When I move it above this strip air view points stops and after moving half of the way it appears on the other side.
Is my phone damaged by water? I splashed some time before a bit of water on the screen, but I get rid of water fastły, so i don't now if it's connected. Especially if it wasn't my first time "moisturizing" screen.
Has anyone similar problem? What was the cause? Is it problem with s-pen (I wish, buying new doesn' require money.), software, this thing in the screen which detects s-pen is damaged or is it any other reason?

Does anybody know how to fix that and how much it'll cost if phone is damaged? I don't have enough money to change whole screen etc. (It's hard to say how much money I can pay for it. I use other currency. I hope it'll fit in 10% of used phone cost or I can fix it on my own. Otherwise i'll be sad. )

PS. Sorry for writing too much text. I'm stressed a bit.

PS2. I forgot to mention that I have glass screen protector, but it was there for months and everything was fine.
And I also have no magnets there, so this isn't the reason.

PS3. I uploaded picture where it doesn't work ( http://imgur.com/a/aO9oq ) as you can see it's not completely straight.

 

[B. Diddy]

Welcome to Android Central! See what happens if you take the screen protector off. It may be a hassle, but if it helps, that'll save you the cost of replacing the screen. (I don't think it's a problem with the S Pen itself.)

If there are any cracks in the screen, or any other breaks in the integrity of the phone's body, then even a relatively brief exposure to water might be enough to cause some damage, if the moisture gets inside the phone.

 

[Mateusz_Obara]

OK. I found this:
https://www.youtube.com/watch?v=9pSoNZNaBQQ
https://www.youtube.com/watch?v=p4NatTlho48

This looks the same as mine.
So i won't take off the screen protector, because it's more probably that the s-pen sensor film isn't working and screen protector costs about half of the price of this film.
This film is actually cheap but i wonder how much would i need to pay for changing it (I don't want to make a risk trying this on my own.). Does anybody know how much?
And can all phone repair points change it (You know, almost only Galaxy Note phones can have this problem)? Or somwhere they can say that you need to change whole screen.
An one more thing: Should i buy this part on my own (It's only avaliable abroad, so I can probably buy this part cheaper or buy at all) and hand it to repair point?

PS. Thanks for help.