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
Use insulation mat as necessary
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Observation:
Using shrouded probes measure the voltage between an earth connection and the pins on connector X50 as below.
With pin 1 being the top left, measure the voltages which should conform to the table below:
With pin 1 being the top left, measure the voltages which should conform to the table below:
| Approx | Voltages | Pin 1 = 3.5vdc | Pin 5 = 3.5vdc |
| Pin 2 = 5vdc | Pin 6 = 0vdc |
| Pin 3 = 0vdc | Pin 7 = 5vdc |
| Pin 4 = 5vdc | Pin 8 = 23vdc |
Isolate as per TOPs P4
and refit as necessary