My Smeg DO4SS-5 Grill does not get hot?

I have recently replaced the grill element in my top oven because it stopped working. Having replaced the element with a new Smeg OEM part, it still does not heat up.
The bottom element (in the top oven) still functions because the oven warms up if I use the oven function albeit all of the heat comes from the bottom element; not from the top.
The top-oven light also works.
Which component should I look to replace next?