Man Roland 200, won't run with edge sensors ON

Hello, I have a problem with the Man Roland 200; it's only working when I hold the button to disable front edge control. Is there a way to test which one is faulty? Or do you know what might cause it? I also notice that sometimes we have this red light on.

Also, those grippers close to sensors that should hold the paper sometimes start moving with a loud sound without any voltage going into the electromagnet.

Thanks for your help.

 

This red light is normal. It goes out when there is a sheet of front marks.
Do you have a black display with 6 buttons?
If you don't have one, the defective photocell can only be diagnosed by a qualified electronics technician on the board that controls it.

 

No, I don't have this display. I feel confident that I can check it; I have some knowledge in electronics. Can you tell me how to measure it or at least how those sensors work?

Also, do you think that this might be why this press won't run? I heard that a few years ago they had a similar issue, and they swapped some relay boards on the back of the press (most likely on U3), and it worked for a month.

I know where this board is located and where all sensors are connected, but I don't know how they're supposed to work.

Do you think that this problem with the electromagnet is also caused by this, or is it just a totally different problem?

 

Check sensor feeder

 

Send a WhatsApp

 

That's my whatsapp +48795513631

 

First you need to learn how the machine works, at least theoretically. For this machine you need ITS electrical diagram. Then you can start looking for the fault.
This is relay contact logic. Almost always the problem is a bad contact on a relay in a 10-20 contact circuit.
I wish you good luck.

 

The error is sensor feeder , the led turn off

 

Sorry for such a late response but I wanted to make sure that everything was working.
So my problem was, as Daniel.Sanchez said, edge control sensors, but the problem was more complex than this.
Long story short, the problem was drained capacitor on the U6 unit (this one in the photo). Later, we had to adjust the machine and now everything is working fine.
Thank you for your help and support.

 

Bien amigo