One of my D20's failed today. We had the lights on for focusing, and then what looked like a lamp failing as it became really bright and then shut off, turned out to actually trip the breaker. Upon turning the breaker back on, the dimmer acts as a CC20 now instead of a D20. Not useless, but not acting as it's preferred to behave. I've seen a lot of discussion on here about SCR's and triacs, and I'd like to better narrow down which part of the dimmer failed before I hand it to my electrician, who will probably want to inspect if before we contact tech support. I don't know that contacting tech support will do much though, as the dimmer was manufactured in Oct. 2003 and is almost certainly beyond warranty.