Hi sir;
Please review this steps;
1) Please check the sensors switch(proximity swtich) , must be in 0.8mms(distance switch cylinder vs sensor switch proximity)
2)Test if there are +24Vdc exactly in the terminal plug 44, CU9.4+CU9.5, and tigh very well the wires, or dirty sensors, or faulty.
3) Test connection flat wire hardness IAR-AR, and exchange if necessary.
4)Adjust the limit switch in the gear box, look for loose wires, dirty contacts, or faulty, replace, and adjust as exactly you can . Turn OFF the machine.
Turn knife carrier down manually, until the mark 1 of the positive cam switch cam correspond with the mark 2 on the gear box, carefully thear Snap action switch!