Our Frigidaire dishwasher (model PLD 2560LCC1, age unknown) stopped working correctly yesterday. It runs top rack only and other buttons (cancel, normal, etc.) are non-responsive. When the door is open, the display flashes CL and the lights are blinking indicating: lower rack; washing; sanitized; clean. Does anyone know what could cause this problem? We were thinking either the "control" or "board" in the control panel might need to be replaced. Please help.