Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Hinge down the PCB housing
Unplug the 6 way connector from the PCB
Measurement:
Test 1:
Measure the resistance between the red and black wires at connection 2 (red) and 4 (black) on the 6 way connector of the PCB.
Expected resistance approx. 4.1kOhms.
Test 2:
Measure the resistance between the red wire at connection 2 (red) and a suitable earth point.
Expected resistance above 1 MOhm.
Measure the resistance between the red and black wires at connection 2 (red) and 4 (black) on the 6 way connector of the PCB.
Expected resistance approx. 4.1kOhms.
Test 2:
Measure the resistance between the red wire at connection 2 (red) and a suitable earth point.
Expected resistance above 1 MOhm.
Isolate as per TOPs P4
and refit as necessary