ew81 lower oven not working?

hi
hotpoint ew 81 lower oven stopped working last week - there was a small pop/bang - the wall switch tripped and so did the fuse box switch - then smoke came out of through top grill (top grill not on - lower oven was) - my brother explained he has a reg problem with his oven (not a hotpoint) and its the oven element - have today replaced oven element - switched oven back on didnt blow switchs but i did get an electrical crackling sound (like a fusing together noise) and an electrical burning smell (oven switched straight off) - anyone suggest what might be the problem - its fan assisted so should fan come on as soon as oven switched on or does fan only come on when certain temperature reached
many thanks
richard