Set Appliance State:

Mains Power Off
Set Multimeter to AC Volts Set meter to measure AC Volts
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Appliance On/Off control set to ON position.
Measure the voltage at the third terminal from the right marked LS (live) and the seventh terminal from the right marked N (neutral) at connector ST2 on the PCB.