Do you have, and can you use, a multimeter?
OK, thanks for that.
Can you post the actual model number of the appliance please?
It should be on a label somewhere on your appliance.
Click here for the 2 types of thermal cut out that have been used on this appliance.
Isolate the power to the appliance, disconnect it from the supply
Take the rear panel off and follow the wiring from the connector block to the clock.
It should have a fuse in line or go through a cut out.
Find this, order the correct part and fit it in place.
Reassemble the appliance.
Restore the power.
See if the clock works.
If it does, set the time and try the oven.
If still nothing it would suggest the clock is faulty.
Unfortunately, without having the multimeter you can't narrow this down and will need to fit parts on a "fit and see what happens" basis.
Hope this is of some help
Let me know how it goes or if you need more help