Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
Selector switch in CH & HW mode
Selector switch in CH & HW mode
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage between pin 3 (orange) and pin 4 (blue) at X9 connector on the PCB.
Mains voltage should be present.
Mains voltage should be present.
Isolate as per TOPs P4
and refit as necessary