Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
Gain access to PCB (use insulation mat as necessary)
Pull connector X1 down slightly to expose test points
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure the voltage between pin 3 (brown) and pin 2 (blue) at X1 on the PCB.
Mains voltage should be present.