Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
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 volts between the Brown wire on the PCB connector X23 and a suitable earth connection.
Expected voltage approximately 28 vdc.
Expected voltage approximately 28 vdc.
Isolate as per TOPs P4
and refit as necessary