Duct keys with a mind of their own on a Heidelberg Speedmaster

[Leedsprinter]

Hi,

I have a 20 or so year old Heidelberg 72 and recently the keys randomly open up or shut down on the run. This happens on all units , though it seems to happen more often on some keys than others. It doesn't happen all the time, or to all at once. A couple of weeks can pass with no probs then a few keys on a duct will open up or shut down on the run. The display on the console doesn't show this. The display continues to show as set. The keys have been cleaned, so it isn't dried ink etc. It sounds to me like a pcb. I have two presses the same age so if it is a suspect board I could swap it and see if the fault shows up on the other press. I'm not sure where to start to look though. Any ideas?

Thanks

 

[duct maestro]

Could be a software problem.

 

[Leedsprinter]

Hi, Thanks for the response. I think the press predates the use of software, but I could be wrong.

Again many thanks for taking the trouble to help.

Peter

 

[Al Ferrari]

What does Heidelberg have to say about it?

Al

 

[junker1984]

Hey Leeds - Monitor which zones are changing on their own and at which unit closely. Sounds like you have sticky keys, but if that were the case the LEDs would be changing. I would swap the MWE boards from a working unit first. You should have received an ops manual for CPC 103 with the press, it breaks down the functions of each board, the monitoring of the key pots and the drive of the motors are performed by the MWE and MOT boards. The memory SPK may also come into play, but I've not seen the memory board cause this issue. Hope this helps your troubleshooting the problem. Steve

 

[Pressmanscooter]

Which console does the press have, the old style or the newer style with the screen (not touch screen)?

 

[Leedsprinter]

If I've uploaded it right, this should show it.
Thanks.

 

[Cornishpastythighs]

I know this has been asked already but have you contacted Heidelberg for any input. You might be chasing this problem for ages without some sort of direction.

 

[Leedsprinter]

Thanks. Heidelberg don't have electricians on the books, they just subcontract to local approved sparkys. Ours just says 'It's a needle in a haystack'. Is there a Heidelberg helpdesk or similar?

Thanks again for all your interest,
Peter

 

[Cornishpastythighs]

The last time I had problems like that was on a 25 year old Komori press it was the electrics overheating inside the console. We installed a small A/C unit and the problem went away, it was caused I guess by the old style computer boards ageing. Just a thought

 

[Leedsprinter]

What a really interesting idea! And easy to remedy. I'll give that a try.
Thanks.

 

[Francois]

Do they close all the way down or do they have a random position up and down?. Does this happen after you set your keys and are in production mode?
Could be the MOT board losing its referance voltage.

controlgraphicsusa.com

 

[Leedsprinter]

Hi Francois,

They open or close to a random position, which can happen anytime during a production run. A couple of weeks can go by without a problem. I suspect it is likely to be a board as all the ducts are affected. I have 2 presses of a similar type and age so maybe I could swap a board and see if the problem occurs on the other press?

Many thanks,
Peter

 

[Leedsprinter]

OK guys, Now I've brought your responses to my printer and questioning him more closely I reckon there are two unrelated issues here, and the problem is not as I described.
One is that when setting the keys some keys open up so far and no further. This sounds like those keys are gunged up with ink and a good strip down and clean will sort the problem, so I'm not concerned about that.

The other, distinct problem is that on unit 4 only there are 4 adjacent keys which shut down completely on the run. It is always the same keys and they don't open up at random, they only close down. This happens about once a week or fortnight. That unit has been cleaned out. Would this be relevant to what you have identified, Francois?

Thanks,
Peter

 

[junker1984]

Leeds, If four consecutive zones are malfunctioning, the problem may be originating at one of the ribbon cables or their plugs or the boards they plug into, both at the CPC console and at the ink fountain itself. Try swapping ribbon cables at the affected distributor board in the fountain with the adjacent cable, etc... or, with any luck, a cable may have a poor connection and simply unplugging and plugging back in will remedy the issue. Good Luck

 

[REYES1377]

View attachment 2587

If I've uploaded it right, this should show it.
Thanks.

Old school!!