Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector CN2 from the PCB

Measurement:

Test 1. Measure for resistance across blue and brown of connector CN2.
Expected resistance approximately 280 kOhms.
Test 2. Measure for resistance across brown (CN2) and a suitable earth connection.
Expected resistance greater than 1Mohm.