Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect the plug marked CON7 on the main control board (PCB 40)

Measurement:

Test 1:
Measure the resistance between the brown and blue wires
of connector CON7 on the main control board.
Resistance should be approximately 180 Ohms.
Test 2:
Measure the resistance between the brown wire of
connector CON7 and a suitable earth point.
Resistance should be 1M Ohm or greater.
Test 3:
Measure the resistance between the blue wire of
connector CON7 and a suitable earth point.
Resistance should be 1M Ohm or greater.