Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect X10 from the PCB

Measurement:

Measure the resistance between the blue and
brown wires on the disconnected plug.
If a MECHANICAL timer is fitted resistance should be approximately 69kOhms.
If an ELECTRONIC timer is fitted resistance should be greater than 1M Ohm.