Creda elect cooker EDCB60 cooling fan running on

Customer reports that he has to “fiddle with the oven and grill knobs”, until the cooling fan cuts out.
It wasn’t always like that, but has been like it for a couple of months.

Creda EDCB60, ser no 78100011.

Searching through other posts, I suspect either the trigger board or a thermostat.

Does this model have a thermostat that controls the cooling fan?
If so, where is it located and what is its part number, please?

Or is it just the trigger board?

And does anyone have a wiring diagram for this cooker, please?

Many thanks,
Pigpen.