Sounds like you have a Clevland oven. But I have no idea what control system, accessories it has. Do you see any trouble codes? Being it starts and runs a cycle before it quits, it sounds like corrupt software may be your issue. Before spending a lot of money on parts I would upgrade and reload the software to the machine. Combi ovens are extremely technical and have a lot of control sensors and feeds to do specific things. And they require very clean power to the control system to prevent problems down the road.