Britannia SI9S6SLXS oven switch?

We have a single oven model with digital programmer. The oven has just decided not to switch on - either manually or via the timer. Have switched off at mains, re-setdigital timer, played with manual oven selector switch all to no avail. When rotating the oven selector swith the oven light does come on - momentarily (20th of a sec or less) and thats it. Any ideas anyone ? Fuses appear to be okay.....