Do I replace the supercharger?? Nose cone???

My supercharger died a slow, intermittent death, years ago. As it died, it seemed more likely to be present on high humidity days, like rainy days...maybe that was just my imagination. Anyway, mechanics have said there is nothing wrong with it, one even "cleaned" it a few months ago, and still nothing. Is there some key sensor or external supply that feeds the supercharger? How do I KNOW if my supercharger needs to be replaced? And, what is this nose cone business, and how do I know if I need that set of parts, as well? Thanks for any help.