Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect HMI cable from controller interface PCB and the main PCB
Measurement:
Measure the resistance between each of the 8 pins in turn on the HMI cable.
Expect continuity / zero resistance on each test.
Expect continuity / zero resistance on each test.
Isolate as per TOPs P4
and refit as necessary