Smeg oven repair

my smeg oven does work when i can eventually get it to work.To get it working i have to turn it on and it makes a noise as if its working but then makes no noise and doesnt heat and then i turn it off again and on until it finally decides to actually heat up, when it does it will work but how can i fix this or does anybody have a clue how it could be fixed as ive been quoted lots to fix???

Wish I could help ya but never heard of a smeg oven before