whats happend to my oven?

I have had my Belling fse60dopx for 14 months we have had to move the cooker into our new kittchen and when we looked at the wire conected to the back of the cooker the plastic casing had all melted and the black wire had started to melt. We put a new cooker wire on and now the cooker workes except the main oven, their is no power to the main oven every thing else works.Please can you tell me what happened.