Pittbull Ultra Lead - Graphic Eq slider issue

Hello, I am the owner of an early VHT/Fryette Ultra lead.
I have an issue with my graphic Eq. The 1.2k slider doesn’t seem to be working . The other sliders are working fine

Is this potentially a cleaning issue, or something more serious .

Does Fryette have a list of “approved amp techs” . I am in Oklahoma