Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove rear control panel cover to expose main PCB

Measurement:

Remove connector H2 from main PCB.
Test 1:
Measure resistance across the brown lead and blue lead connection (1 and 4) on the connector marked H2 on the main PCB.
Test 2:
Measure resistance across the live and suitable Earth.
Expected resistance O.L or greater than 1MOhm on both tests.