Heidelberg qm 46 2 double sheet sensor problem

Hello, i have heidelberg qm 46 2 and when i try adjust the double sheet the red light is off, it doesn't come on. Can anybody help me with this? Thank you

 

Hi sir:
Look very well the surface of the double sheet.
1) Clean the surface of the double sheet
2) Look for dirty, or oil, or gread in the connector of sensor.
3) Look if the connector, is broken or loose wires, or broken, clean with special contacts cleaner electronic.
4) Meausre +24Vdc pin 1 vs pin2. if there the Double sheet can be faulty and replace, or repair. See your schematic diagrams