Set Appliance State:

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

Measurement:

Measure for DC volts across pins 42 (red) and 43 (white) of connector X10.
Expected voltage approximately 5.0 Vdc.