If the variable resistor isn't working then maybe it needs replacing. Whatever damaged the knob could have also pushed the variable resistor down into the PCB and caused physical damage (cracks) to the PCB. Something that might clear up if you push down and/or possibly get worse over time.

The part is soldered to the PNC board.

It happens that the assignable knobs (1-4) and super knob use the same variable resistor part.

Thanks for the answers from both of you. I know it's really difficult to tell if something other than the super knob itself without investigating it. Since I never taken the super knob apart, I don’t know how the potentiometer should feel, should it be loose or tight?

I've order the spare part for the super knob - ZQ400100 from Yamaha and hopefully it only that that is damaged. If not I'll probably send it in for repair. For myself, I could live without it, but if I decide to sell the modx later, I want it to be in good condition.

BTW: I've had a problem with my superknob too. It's different from yours, I suppose, because I don't sense the variable resistor (VR) is "too loose" or "too tight". Seems the same as ever. The plastic holding the superknob to the VR is broken so it doesn't quite "grab on" correctly.

I still have it in my "shopping basket" from a year or so ago. Since they're not that expensive I ordered 2 to keep one as a spare.

Here's what the board looks like:

https://www.keyboardkountry.com/replacement-panel-board-pnc-for-yamaha-modx8/

The superknob is in the lower left of this picture.

Jason, I have the exact same problem with the plastic holding the super knob and I have ordered a replacement. I am not sure if the VR itself is broken because I don’t know how it supposed to feel. When I remove the super knob, the VR feels a bit like a joystick - it can be moved in all directions - and I need to press it down a bit in order to change the parameter values. I recorded a small video, showing how it looks. Maybe I can just tightening it somehow, but I don’t know how. https://streamable.com/kzvval

Just verified through testing that even with the knob removed, the shaft DOES NOT typically travel in that manner.
Your alternatives are those I described in my prior post because I am unable to speak to what may or may not be damaged or functioning incorrectly.
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One option if it is too expensive to get the superknob repaired would be to use an FC7 foot controller. I use that all the time on my Montage and very rarely turn the superknob by hand. Would this solve the problems?

This pedal is a bit cheaper, and stickier to your foot, and has an adjustment dial right on its left side, and two modes of operation, for other synths etc:

https://www.sweetwater.com/store/detail/PedalExp--m-audio-ex-p-expression-pedal

As John said, once you have a foot pedal hooked up, you'll probably never again reach for the SuperKnob, only look at its lights for reference.

I'm a left foot braker, so it took about 2 seconds to get into using this control pedal with my left foot. Strongly suggest you train yourself to do this so that your right foot stays on sustain and/or hovering over accelerator to keep/build revs and balance the car as needed/desired.

Daughter, who is not yet a driver, was taking time to get fluent with the control pedal. Fastest improvement came when I showed her how to use it like a wah-wah pedal to pump, or "breathe" a sound in conjunction with her chord timings. A few minutes of this and her muscle-mind connection and intention became second nature.

This strong and overt left foot usage of the SuperKnob then makes it easier to come up with ways that are useful/creative in terms of automating the SuperKnob's animations with the Motion Sequencer, as you can "practice" the animations with your foot whilst playing.

If fixing the superknob is out of the question due to cost, an FC7 foot controller could be used instead. On my Montage, I rely heavily on that feature and only occasionally manually adjust the superknob. Would that be an adequate solution? wordle today