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 required)
Remove connector 100 from the PCB and make safe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure for AC voltage on pins 1 and 3 where
connector 100 was fitted.
Expect mains voltage.
Note.
Ensure a good connection is made or misdiagnosis will occur.