Samsung oven bf3on3t11 can anyone help please.

Hi all really hope someone can help me. I was cooking the other day when my oven made a big loud bang and knocked all my electrics as my oven was just out of it two year warranty I stripped it down to find some cables melted and circuit board burnt out I have replaced circuit board and that part of oven is now working fine. My problem is I an now no longer my oven to work in convection I no its not the element as it is brand new, the fan is coming on but no heat is been produced. Everything else on the oven is working fine such as top and bottom heat and grill. Any suggestions would greatly be appreciated as running out of time before Christmas diner is ruined