Touch screen or logic board?

Hello i have a non technical friend who is wondering if i can fix his 3ds touch screen but I don't know if its the screen or the controller for it, here are the symptoms;

The touch screen continually pulls to the right (dont know if its "swiping" or just stuck far right),

All other touch inputs are rejected,

The rest of the system works fine for what we can test as we cant select anything, it collects motion point or whatever there called and recognizes games

Powers on and off fine.

So is this the screen its self and if so does anyone know ware i can get a replacement screen? Or is it the logic board touch controller?