Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect connector HV1 from the PCB

Measurement:

Test 1:
Measure the resistance between pin 5 (brown) and pin 6 (blue) on HV1.
Resistance should be greater than 1M Ohm (or O.L on meter).
Test 2:
Measure the resistance between pin 5 (brown) and pin 4 (green/yellow) on HV1.
Resistance should be greater than 1M Ohm (or O.L on meter).
Are the resistances measured as expected?