Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove connector CN11 from the PCB

Measurement:

Test 1.
Measure the resistance between the 2 outer pins
on connector CN11.
Expected resistance approx. 53 Ohms.
Test 2.
Measure the resistance between each of the pins on
connector CN11 in turn to a suitable earth point.
Expected resistance greater than 1 MOhm on each test.
A reading of O.L is acceptable on test 2 as this is greater than 1 MOhm.