someone above mentioned the 24 volts. if I remember right, DR is an 120volt controlled relay and the rest are 24volt. similar problem a few years back were the 24 volts was lost on the relay board itself, resulting in the exact condition Greg describes and no fuses blew either. something to do with a regulator(?) at the 24 volt source on the relay board itself. I remember we were able to bypass it until a new board could be installed. pardon my vague recollections, but maybe it'll stir some thought and investigation.
