Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance

Measurement:

While pushing the reset switch down measure the resistance between pins 6 and 7 at CN104 on the control PCB.
Resistance should be short circuit (zero resistance).
Release the reset switch, resistance
should change to O.L. or a high resistance reading.