Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Gain access to PCB (use Insulation Mat as required)
Remove the wires from the selector switch noting their locations
Attach crocodile clips to terminals 4 and d
Remove the wires from the selector switch noting their locations
Attach crocodile clips to terminals 4 and d
Measurement:
Test 1:
Measure the resistance between terminals 4 and d.
Expect approximately 1MOhm or greater.
Test 2:
Turn the selector switch to the reset position while observing the multimeter.
Continuity / zero resistance should be measured between the terminals 4 and d when the switch is in the reset position.
Are the resistances as expected?
Measure the resistance between terminals 4 and d.
Expect approximately 1MOhm or greater.
Test 2:
Turn the selector switch to the reset position while observing the multimeter.
Continuity / zero resistance should be measured between the terminals 4 and d when the switch is in the reset position.
Are the resistances as expected?
Isolate as per TOPs P4
and refit as necessary