Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect X1 from the PCB
Disconnect plug from spark generator
(Push away from spark generator not downwards, easier if spark generator is removed from appliance)

Measurement:

Check for continuity (zero resistance) on
each of the three wires running from
the spark generator to X1 at the PCB.
Inspect the harness and plugs for damage
and good overall condition.