Yes, undo the bolts holding the two thick solid wires from the txfmr to the "ears" on the rectifier, check for 15 to 30 volts AC across those wires.
so had to work late so only just got to this - with the transformer unbolted I get nothing on any switch setting - actually I did see 3v on one trigger pull as I was switching through the switches, but a retry wasn't there - certainly no 15 to 30v seen on any setting...