Set Appliance State:
Mains Power Off
Set Multimeter to DC Volts 
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the DC voltage between Pin 2 (Red) and Pin 3 (Blue) expect approximately 4.9 VDC
Isolate as per TOPs P4
and refit as necessary