Dipomat Range 850 ADP5426 – Grill power fault

hello
im after a bit of knowledge if anyone can help me, i have a Dipomat Range 850 ADP5426 and the range works fine apart from the grill section.

Here is what Ive clarified so far

– There is no damage to the dial
– The power indicator doesn’t illuminate with the dial is turned on
– Seems there’s no power to the grill as no heat is generated
– Ive tested the element for earth leakage, the element is working fine

I’m an electrician but cant say that clued up on cookers 😥 , Ive had a look on a spares website through the 100+ parts available for my cooker and the only part that seems relative is a Cooker griddle / Grill energy regulator

thanks for your time

jack