does it look like a transistor with heat fins or heat sink?
only way to test her is to install intot he circuit, as there is a trigger wire to control the speed.
Unlike the old style using wire resistors to drop the voltage.
my 420 sel I just took a resistor box with perforated holes form a w123 and stuck her inside the air box, so air will cool off the resistors.
Running at med speed now, i have a 3 way switch so I can reg the speed to off, slow high.

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