Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove connector ST17 from the PCB
If available use the Worcester test PCB to assist resistance test
If available use the Worcester test PCB to assist resistance test
Measurement:
Measure the resistance of the pins on connector ST17.
Resistances should conform as per the table below:
Resistances should conform as per the table below:
Isolate as per TOPs P4
and refit as necessary