Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to DC Volts Set meter to measure DC Volts
Gain access to PCB (use Insulation Mat as required)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow fan purge to complete (2 minutes).
Measure the DC voltage between each of the wires listed in the table below on connector X9 and a suitable earth, voltages should conform approximately to the table below:
PinDC Volts
123.8
2 23.8
323.8
423.8
523.8
623.8