Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X1 from the PCB

Measurement:

Test 1.
Measure for resistance between pin 5 (brown)
and pin 6 (blue) on connector X1.
Expected resistance approximately 160 Ohms.
Test 2.
Measure for resistance between pin 5 (brown) on connector X1 and a suitable earth connection.
Expected resistance greater than 1 MOhm (or O.L).