Hi,
i have a vintage minimoog that a few of the keys are ‘jumping’ when I play them. They oscillate up and down and then stabilize. I assume there are dirty contacts on these keys? If that’s the problem, how do i clean them? Any help is appreciated. thanks…+
More likely it’s in need of new rubber key bushings.
Do a Google search for Archive Sound and bushings.
… and if you’re not mechanically inclined, refer the work to someone qualified. 
Doing a rebush job incorrectly can cause all sorts of frustrating additional problems.
thanks…i’m not sure if i’d want to risk pulling it apart. Anyone know of a good synth repair shop, ideally south of Boston?