Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector CN6 from the PCB

Measurement:

Test 1:
Measure the resistance between pin 39 (blue)
and pin 40 (brown) on connector CN6.
Expected resistance approximately 0.8 Kohms.
Test 2 Resistance to Earth:
Measure the resistance between pin 40 (brown)
on connector CN6 and a suitable Earth point.
Expected resistance greater than 1 Mohm.