Abstract: An electronic device comprising a liquid crystal display and a control board, the electrical tracks of the board and of the display being connected by a connector, the control board including a microcontroller able to apply an electrical voltage to at least one connection terminal in order to display given information on the display, characterised by the fact that the control board includes a diagnostic device which is designed to generate a voltage pulse at connection terminals and to measure the resulting electrical voltage in order to determine the state of the connection between the display and the board as a function of the value of the measured electrical voltage.