Happened the other day, took out the monitor speakers too. I am not sure how this happened, but the production director reported that the speakers began making very loud squeal. Somebody finally thought to turn off the amp using the conveniently located on/off switch on the front panel.
The two watt resistor is burned open. Also, this got so hot it burned a hole in the circuit board below it. Truth be told, I think this amp was about 25 years old and due to be replaced when the new studios were built out.
I’ve seen these Crown amplifiers self destruct in the past.