SM74-4 delivery pile can't go up

Hi all, I have a delivery pile for SM74-4 that won't go up. It can go downwards but not upwards. Need advice on how to get it back to it's normal operation.

 

you can begin by making sure that your rear jogger has not engaged the limit switch. Are you certain that the delivery pile chain has not lost its proper engagement with the sprockets? There should also be limit switches just above ground level that could be all gunked up with powder and such. These lower limit switches will be engaged with little half moon shaped parts on the delivery pile chain.

 

Check the limit switches mate. Most of the times these are the culprits.
You should also check for faulty relays in the electrical cabinet.
If you don't have the proper schematic, then you would have to find the relay yourself.

 

It was the pile drop sensor, the coin shaped sensor. It was faulty, new part has been installed. Thanks everyone for the advice.

 

Thanks for the feedback.