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 necessary)
Gas On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage between brown (8) at X401 and a suitable earth.
Expect approximately 33 Vdc.
Is the voltage measured as expected?
Expect approximately 33 Vdc.
Is the voltage measured as expected?
Isolate as per TOPs P4
and refit as necessary