Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X3 from the PCB

Measurement:

Test 1.
Measure the resistance between pin 4 (brown)
and pin 5 (blue) wire at X3 on the PCB.
Expected resistance greater than 1MΩ (or O.L).
Test 2.
Measure for resistance between pin 4 (brown)
on X3 to a suitable earth connection.
Expected resistance greater than 1MΩ (or O.L).
Note:
Wires may be multi coloured.