Jog Wheel Problem with Pioneer DDJ-SX

Hey community, i hope this is the correct thread.

i bought the pioneer ddj sx last year, when i unboxed it and tested the left jog wheel, there was a very silent scratchy noise once per spin. there was no resistance so i didn't really think this might become a problem. today, i came home, turned on some music and the ddj sx worked like it did the last months but suddenly, when i spinned the left jog wheel der was a louder scratchy noise (i'm not talking about the musik, i'm talking about the hardware only) and i could definetely notice resistance. it just sounds and feels as if there was a small stone under the jog wheel, inside the device, which scratches on the jog wheel once per spin. i cared for the device very well so i have no idea what the problem is. may i unscrew it or something like that? don't know how to help myself...

thanks for your support