Sluggish volume knob on Omni

[chrisdee]

This is probably a first.

I had tightened the rack screws way to hard earlier so I had to use a range of different tools to finally loosen the screws.
Both electric and manual. I must have used one hour

After this process the volume knob on my Omni has become sluggish. When rotating every 360 degrees it's giving me much more resistance.

Other than this the Omni seems to work fine, so Im wondering if I should open it up to se if something is loose or in the way
rather than delivering it to service and parting with it for a lenthy period of time ?

Any thoughts ?