Neff U1661 Main Oven

We have an old neff U1661 that has developed a main oven problem. The fan element stopped working a long time ago (and I was too lazy to replace it), but last weekend mid-Sunday roast a fault occurred and tripped the RCD after the oven had been on and working normally for a while. The symptoms are that the main oven no longer works and the clock/timer is also not operational. I have removed the oven from it’s unit and the main oven controller has burned tracks on the PCB under the inboard power relay. A continuity check shows that the fan element is open circuit (no surprise) but there is continuity between the outside terminals and also the inner terminals of the top element also between the two terminals in the bottom corners of the oven (which I assume are for the bottom element). There is no continuity between any of the terminals and earth, and the measurements were taken with the rear panel removed.

I struggle to believe that the relay in the controller has spontaneously gone into meltdown as I would have expected a short to cause this damage, but I can’t seem to find a plausible cause so I am reluctant to spend a couple of hundred pounds on a new controller without identifying a definitive reason for the damage.

I appreciate that the oven is now old, but I don’t subscribe to the view that appliances should be thrown away when they go wrong unless the cost to repair isn’t economic: Anyone have any thoughts or guidance?

Thanks in advance, Mike