Set Appliance State:

Gas Off
Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Unplug connector CN4

Measurement:

Measure resistance across connection 1 & 2 (Purple wires) on connector CN4.
This should be in the range 2K Ohms (Hot) to 13K Ohms (Cold).
Replace connector CN4.
Note:
This test should be carried out on the
disconnected connector, not on the PCB.