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 voltage across pin13 (black lead) of connector X2 and a suitable earth connection.
Expected voltage approximately 5 Vdc.
Note:
Pins are numbered on the connector.