Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector X4 / X7 from the PCB
Remove the wiring from terminals 4 and 5 at the incoming terminal strip
Remove the wiring from terminals 4 and 5 at the incoming terminal strip
Measurement:
Measure the resistance between pins 5 and 6 at connector X4/X7.
Expect approximately 1MOhm.
(O.L is acceptable because it is greater than 1MOhm)
Is the resistance measured as expected?
Expect approximately 1MOhm.
(O.L is acceptable because it is greater than 1MOhm)
Is the resistance measured as expected?
Isolate as per TOPs P4
and refit as necessary