Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector X2 from the PCB

Measurement:

Test 1:
Measure the resistance between pin 9 and pin 21 on connector X2.
Expect a resistance of approximately 52 ohms.
Test 2:
Measure the resistance between pin 9 on connector X2 and a suitable earth.
Expected a resistance of 1MOhm or greater.
(O.L is acceptable because it is greater than 1MOhm)
Are the resistances measured as expected?