What could be causing problem:  

1. The down and in synch sensor may have failed

2. The capture fork cylcinder may have failed

3. The capture fork valve may have failed

4. The PLC output may have failed 

Possible solutions


1. The blue light on top of the machine is also electrically tied to the down and in synch sensor, if the blue light does not come on when the platens are properly lined up, the sensor is likely at fault.  The sensor also has a red light on it, check to ensure that when the cam follower is lined up to the sensor the light comes on.  It is not uncommon for the sensor to be too far away from the cam follower to activate.  Have customer try pushing sensor bracket toward cam follower and see if light will come on.  If light wont come on even under contact with the cam follower, replace the sensor.

2. The PLC will only allow the capture fork to engage if the table is in synch(see number 1). If the capture fork will not engage even with the down and in synch sensor activated(use sensor test to determine), then have the customer manually cycle the valve using the hardware test.  If cylinder still does not shift, try manually shifting using the push pin on the valve itself.  If Valves shifts but cylinder does not engage, then troubleshoot cylinder or air line.  If valve does not shift, the replace valve.  If valve will shift when manually cycled at the valve, by not when cycled through the hardware test mode, suspect PLC output.

3. If the Rod end at the capture fork breaks, the linkage will not be lined up or connected to the capture fork resulting in cylinder movement but no capture fork movement.