Thank you Gary,
I assume you mean the source of the spark (the ignition) which needs cleaning etc? The hob itself and all the spark points are perfectly clean.
I don't know how to access the wiring /mechanism behind the facia. There is no clear indication of which screws I need to remove to enable me to gain access and undertake an inspection and repair. Information of how to do that would be ideal.
Don't worry Gary, I have fixed it and all is well.
All the best,