Do not guess by opening electrical fittings or tracing concealed wiring. The installation needs a clear, safe means of control.
What the observation means
A nearby switch may belong to an oven, hood or another appliance. If isolation is needed for a hazard, seek appropriate electrical help rather than experimenting around wet or hot equipment.
A useful next step
Tell the service team that the supply control is uncertain. A competent person can identify and label the correct arrangement. Do not use a display going blank as permission to work on internal parts yourself.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.