“Firstly,We apologize that you are experiencing issues with your unit's volume control.
The volume knob on this model the 7012, can be removed by pulling the knob gently away from the unit, towards you. The knob should slide forward revealing the turning post. You can use a general non-corrosive cleaner or an electrical contact cleaner on the control knob as well as the turning post, use a cloth or paper towel to wipe away any excess fluids and/or debris. Allow a few minutes to dry and reinsert the volume knob back on the turning post.
If cleaning the volume knob and post did not correct the issue, then the next step would be to do a factory reset on the unit, however, all saved settings and preferences will be erased and the unit will be reset to factory default settings. To perform this step, turn the receiver off, press Game + Info then press the power button until "initialized" appears on the AVR display. “
Well I took of the knob and I doubt a spray cn get behind the nut holding the mechanism in place