Set Appliance State:

Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Remove the connector plug from X1
Do not measure the resistance on Main Driver Board

Measurement:

Is resistance between:
Purple and Yellow connections approximately 10 kOhms?
Purple and Pink connections approximately 0 - 10 kOhms?
Replace connector plug into X1 after measurements are complete.