I acquired a Hakko 470b desoldering station that won't heat up. I assume that it's got a bad heating element, but I'm not sure, so I tried to test for voltage. I get no voltage. My first assumption was that the base that is bad, but after thinking about it for a minute I thought that a failsafe design would rely on the temperature sensor to be operating before heating up the element, which would prevent the base from sending power if the thermocouple is bad. I don't know enough about the operation of these to know how to test that though.
Am I correct about this type of failsafe, and if so, how do I test that I will get voltage to the heating element if I have a good thermocouple? In other words, what do I have to do to the thermocouple input to get the base to send voltage to the heating element output?
Thanks