I work on electronics for a living and see this all the time. In severe cases, cleaning all of the "gunk" off the circuit board and controls will alter the tuning of the circuitry so drastically that it will no longer function even though it was working fine before cleaning. The tar / nicotene / dust particles have become conductive and are altering the tuning of the circuitry. Once this is removed, a complete realignment is in order to bring it back into normal operation. Keep this in mind if your thinking about grabbing a can of contact cleaner and going to town with a toothbrush. The scary thing is that all of this "sticky gunk" collects in places that are not exposed to high airflow, like the insides of components. Can you imagine what the lungs of these people look like when being directly exposed to inhaling this stuff instead of what has "strayed" off into the air and the surrounding contents (such as the audio gear in question) ???? It boggles the mind sometimes..... Sean
