Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Remove connector CN5 from PCB.

Measurement:

Test 1 :
Measure the resistance between pin 1 (black) and pin 3 (black) on connector CN5.
Expect a resistance of approximately 20 Ohms.
Test 2 :
Measure the resistance between pin 6 (red) and pin 7 (red) on connector CN5
Expect a resistance of approximately 2 Ohms.
Test 3 :
Measure the resistance between all the above pins to a suitable earth.
Expect a resistance 1 Mohm or greater.