Checks to be carried out in the following order:
1) Check that the lid and, more specifically, its
magnet, are correctly positioned.
2) Check (with an ohmmeter) that the safety switch’s
contact is closed. Check the relevant wiring. If
necessary, remove the lid and place a sufficiently
powerful magnet next to the magnetic switch.
If the switch is properly closed but this message
remains on the screen, either get the control board
checked over or have it replaced.