This is from the SoundStage Review (http://www.soundstage.com/revequip/duvall07.htm)
"Twice during my time with the CL-20, the music died into silence in mid-song. While there was no loss of power to the unit, and the display kept on ticking, the output sputtered away into silence. Remembering similar problems with the Audio Alchemy gear of yore, turning off the unit and unplugging the power cord for five minutes did the trick. I suspected there was a microprocessor somewhere inside that needed resetting, which the service techs at CAL thought was correct. Engineering however thought that because of the switching of various clocks, that a simple field fix whereby snipping a small resistor that connects a couple of pins across an IC chip would better synchronize the various clocks. I performed the five-minute vasectomy of the resistor, and the problem has not returned. One other operational note: If you push the open/close tray button prior to depressing the power button, the unit will appear to power up and the display will show the disc playing after pushing play, but you may not get sound. Turn the power off with the power switch and then back on, and everything operates as it should. The tray button should not be thought of as the power on switch."