Cyan dropped on VS-640i

[Mata]

Hi all

I have a problem with my Duel CMYK Roland VS-640i.

I have a perfect nozzle pattern on all my patterns except both Cyans, 1 cyan has one deflected nozzle (Nothing major and can cope with that) but the other cyan is pretty much useless.

The VS-640i has only one head and has pretty light use. I have changed the damper, capping station, pump and still no difference. The thing is the ink comes back 80% at least after I did it.

When I changed the damper, I did a medium clean, the cyan came back 80%, i then did another to try and get the remaining nozzles back and although some came back I was still to far off. So I did another medium clean and the nozzle start disappearing again.

Anyone have an idea what's causing this?

I started all this as when I was printing heavy cyan prints I would get roughly every 6ish inches a faded line about 1-2 cm across the print making the prints unusable.

Thanks

 

[Mata]

Anyone?

I just don't understand why I can get it back then it goes after a few cleans again.

 

[sheitmar]

Oem inks? Is the damper in the correct way? If backwards the diaphragm won't be able to expand properly reducing how much ink is in the damper. I had a customer with the same problem you are having and they put it in the wrong way. You would have mentioned it but please confirm that you don't have air in your lines. Try a new ink cartridge as well, or at least make sure it's mostly full. Check the cap adjustment but I'm sure it's fine if you aren't having problems with other colours.

 

[sheitmar]

One other thing - make sure the o-rings in the damper are in place correctly - it's easy to miss and can cause a world of problems.

 

[Mata]

Can the dampers go in the wrong way? I've attached a picture of my type of damper and other than installing it upside down which I didn't think you could do, does it matter what side it's facing?

The two parts at the top that fill with ink and the round bit at the bottom, if it faced towards the left side of the printer it would still output the same if those parts faced the right side of the printer?

In regards to air in the line, how do I get this out?

 

[sheitmar]

The dampers won't fit upside down but can be installed backwards, so yes the direction they face matters. On your photo you can see the position of the diaphragms (larger circles), they need to be staggered so that they are not directly facing each other. If they are facing each other they won't be able to properly expand to fill. It's an easy oversight. I don't believe that the left or right direction of all the dampers matter, just that they are all facing the same way.

If you have air in the line above the damper, you could have an air leak in the line - could be at a joint or in the line itself. You might have to trace it back to the cartridge. Definitely throw in a different ink cartridge just to rule out that it's faulty first before you tear the whole printer apart to check though (speaking from experience on that one!!). I would try a powerful cleaning, if you don't have an active leak that should fix the problem. If it doesn't go away, you can do further tests by using a syringe to try to pull ink out (above the damper, just be careful not to spill ink anywhere).

Another method instead of a powerful cleaning is to try to pull ink from below the cap tops with the syringe. Because the cap has two lines though, you need to clamp off one line. Pull carefully, you can potentially damage the head if you go too fast. So the print head is parked, cap tops are engaged. You are pulling ink through the dampers, through the head, into the cap and into the syringe. If you notice a lot of air coming in to the syringe at this point, then I would suggest the cap top is either faulty or the cap adjustment is wrong, reducing the effectiveness of the cleaning cycles.

Good luck!

 

[GTSTech_1]

Instead of pulling with a syringe, I would suggest doing a choke clean. If you don't know about choke cleaning, refer to your owners manual, page 75.

Just my .02