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 the brown
and blue pins on connector X3.
Test 2:
Measure the resistance between the black
and blue pins on connector X3.
Expected resistance on both tests should be
approximately 8.5 kOhms or greater.
Test 3:
Measure the resistance between the black and
brown pins separately to a suitable earth.
Expected resistance on each test greater than 1 Mohm.