The Light Processor is not correctly installed.

Check if the Light Processor is properly installed. Ensure that the fixation screws (reference 1 image) at the foot of the Light Processor are fastened. See service manual chapter "Installation of the light processor assembly".

Micro switch (reference 2 image) disconnected from the wire unit (reference 3 image).

Check if the micro switch is connected with the wire unit.

Wire unit of the micro switch (reference 4 image) disconnected from the Signal Backplane.

Check if the wire unit (reference 4 image) is plugged in on the Signal Backplane.

Defect micro switch (reference 2 image).

Replace the micro switch.