Coincidentally, the power switch on my 40 y.o. RF30 clone failed on Friday. It turned out that the switch contact for the neutral line were burned beyond salvage. The switch on my machine is a 3PST and was wired so that all three lines, load, neutral, and ground were switched. I moved the neutral line to the ground contacts and used the input terminal from the neutral contacts as a tie point for the ground wires. IMO, the ground line shouldn't be switched anyway. hopefully, now good for another forty years.