Excuse my ignorance but I'm not a pressman and not sure of the terminology. We have a problem with the black unit whereas it runs really heavy. It was explained to me by the pressman (before he quit) that there are 3 things in the unit and that when the first one starts to fail, then the other 2 will follow and it's expensive. Does anyone know what he was referring to so that I can pass that information along? Thank you.