Im gettin my qd5 bak from repair tonight, i was jus wandering, my optical fader in the qd5 is not as loose as it was when i first bought it. brand new it was light as a feather. is there a way i can take the fader apart and clean it? if so what lubricant should i use? i havenet taken it apart cuz its a optical fader.

what happen that it needed repair