Electrical smell, fan won't go off, smeg oven?

When we put our Smeg oven on it does heat up but there is a strange electrical smell and when it's turned off, the fan seems to stay on permanently rather than going off when the oven has cooled.

The only way to stop it is to switch it off on the isolator switch on the wall!

We've already replaced an element on this machine and don't want to throw lots of money at it getting an engineer out to assess.

Does anyone know what it is please??

Gratefully
Stephen