Oven shutdown

I recently obtained a used Dacor double wall oven, the top oven of which is a "true" convection oven, marked "Convection Plus." This model has dials for the oven controls, and the dial to set the cooking mode for the convection oven lights the top and bottom burner (broil and bake) mode indicators together when the dial is set to the off position. I lack a user's manual for this unit, but I think this might be an error indicator.

The primary symptom is that attempts to start the convection oven in any cooking mode end about two seconds later without any power being delivered to the heating elements or the convection fan. The readout simply eliminates the temperature and mode, and the whole unit turns itself off.

I would appreciate any guidance you might have about how to diagnose which of the circuit boards might be delivering this error, how to diagnose it, or what experience shows will get this marvelous unit working.

So far, I have pulled the lower element to check for wire burning or bad connection, but see nothing amiss. I have also checked the circuitry underneath the top cover, found two fusible links that were fine. The top oven is in beautiful condition -- apparently this problem plagued the previous owner, because the bottom, conventional oven is dirty and obviously hard-used.

Thank you for any help you can provide.

Chris