Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Gain access to PCB (use Insulation Mat as required)
Disconnect A2 from the PCB
Disconnect the blue wire from the APS

Measurement:

Measure resistance between the blue wire of the APS and connection 9 (furthest right) on A2.
Short circuit expected.