Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector CN7 from the PCB

Measurement:

Test 1:
Measure the resistance between pin 48 (blue)
and pin 49 (brown) on connector CN7.
Expected resistance greater than 1 Mohm.
Test 2: Resistance to Earth
Measure the resistance between pin 49 (brown)
on connector CN7 and a suitable Earth point.
Expected resistance greater than 1 Mohm.