I think he meant that the circuit board had a break that would cut out at high amps but then weld itself back together so it functioned normally at low amps setting. Not to say that the circuit itself was seeing high amps but what it was controlling was seeing the amps. Most circuit boards are 120 volts down to as little as a few millivolts and control larger amp circuits. I am just guessing but I suspect that the circuit voltage fluctuated depending on the amp setting in the machine. At some point the voltage was high enough to melt the solder on the circuit board and break the contact but somehow would fuse back together as it cooled .