Second vote for blown
SCR here. When they go, that's what you get, solid on. Plug a 100
watt houselamp into it and listen to the
bulb, then plug the same lamp in another
channel that is at 100%. If it's blown, you will hear a small amount of "lamp sing" from the bulb on the good
dimmer, but nothing on the blown channel. Even at 100% you usually can hear some sing, but when the SCR is gone, its like plugging it into wall outlet. Nothing!