Gas cooker electrical fault?

It's a Parkinson Cowen Ovation 60 GLXa

The clock/timer does not show - at all.
The main oven does not light.

Yesterday there was a (brief) power cut to the electrical supply.
The manual says:

"If the cooker is switched off at the socket the clock will stop. When you 1st switch on the power, a series of dashes will appear on the display and the clock can be re-set."
"If the cooker will not light because there is an electrical power failure such as a power cut you cannot use the main oven"

So now that power is restored (yes, the oven lights etc work) my questions are:

1) why do the dashes not appear on the clock panel and how to re-set the clock without them?
2) why does the oven not now work and how to get it working?

Is there perhaps some simple electrical 're-set' that is needed which is not explained in the manual?