We have a Thermador Cook N Vent, model CBS36RS. Our fan works fine; however, after using it this week, it will not go down. The movement was fine and has never been a problem, raised it this time, used it (with fan running) for 30-40 minutes. When finished, turned off fan, pushed button to put it down...nothing! Fan still works. Is it the switch or something else. It, too, is the small push button with three wires going down to another connection about three inches long. My husband has it open to this point, but not sure what we need to do. Can really find a part number on the switch, just numbers on the wiring. He feels that is not a part number.