SM 52 Delivery pile fails to raise

Hello all,
The delivery pile on our sm52 recently stopped working correctly. The only way to raise the delivery pile is to lower the feeder pile the whole way, idle the press, and engage the feeder. While the feeder pile is rising automatically, repeatedly pressing the delivery pile up button raises the delivery pile in tiny increments. Otherwise it won't rise at all. The limit switches seem to be working and the delivery pile lowers automatically as it should when printing, so I assume the top of delivery pile height sensor is working.
Any ideas?

Thanks in advance!

 

Hi Sir:

I strong recommend to review + and test the following Limit Switch + Sensors, for loose, wires, dirty, lack of voltages, or Faulty and Replace it.
12S33 Upper main pile limitation
12S34 Bottom main pile limitation
12B35 Upper edge of pile Receiver (light barrier)
12B35a Upper edge of pile Transmitter (light
barrier)
12S38 Overshooting control
12S41 Pile stop
12S42 Pile down
12B122 Automatic pile height control

 

Thanks very much for answering. The function of these switches seems correct, except for 12B35 and 12B35a, which I can't seem to find. Maybe this press doesn't have them?? As far as I can tell, the only sensor for top of delivery pile position is the 12B122. I did discover that if I insert the fork for nonstop delivery cart change (triggering both 12S41 and 12S42) everything works as it should! Does this sound like a problem with 12S41 or 12S42, or does it sound like a workaround covering up another problem?
Thanks!

 

By that reason, test it.

Always there are some the same problem, limit switch or sensors.

Good luck

 

Hi sit
sir the lateral tabs there is a sensor, clean it and ensure that the tab on the tab is not blocked, as chock said this type of problem is mainly due to dirty or defective sensors, alignment of the sensors

 

Remember, test the regulated power supply!! .in tolerance!!

 

Test the regulated power supply, in tolerance.

Blessings

 

Thank you both, Chock and Adil for your help! This puts us on the right track. Very much appreciated!!

 

Ok, Sir.
Blessings

 

Be welcome .
Good luck

 

Thanks again for your help. I wasn't quite sure what I was looking for, and sensors 12B35 and 12B35a were so dirty I couldn't even see that there was a sensor there‍♂️. Cleaning them fixed the problem