K bleeding into Y (JV33)

[MikeD]

Black is migrating into both sections of yellow on the test print of one of the JV33 printers.
When printing a yellow shape, there is a muddy line between passes. Media comp is good though.

What would cause this?

Should the cap top and black dampers be replaced? Would a pump tube wash help?
(normal clean and nozzle wash did not.)


Thanks!

 

[MikeD]

Since the black is in both yellow areas of the test print, and none of the wash cycles have cleared it up, should I change the head cap and two black dampers? The dampers actually look fine, so I would start with the cap head.

What do you all think?

 

[Robert M]

Cap

I would change the cap top out first. Make sure your pump is pulling down ink in both tubes

 

[MikeD]

went to change the cap head and saw that the tube leading from the wash Cartridge to the cap is worn. These were all supposed to be repaired by mimaki after they noticed the problem, but obviously this printer was not repaired. waiting for new tubes before replacing anything else. if that doesn't work, cap head is next.

 

[MikeD]

lines from wash to cap station

Above the capping station the tubing from the wash cartridge is connected to a stainless elbow. When the mechanism turns to get out of the way of the print head, it wears on the metal cover. Mimaki was supposed to fix all printers, but some techs did it, and some ignored it. Mine had 3 holes in that area of wear. I scabbed in a larger tube and everything seems to be fixed for now.
I requested the real parts to be sent in asap. Hopefully this is all it is.

 

[Masseria]

ok lets wait for the repair..
attach pictures of what you are talking about so we can help you solve it.

in my opinion you could be able to camuflage the K migration to the Y, with a new Profile. but i dont know what kind of work you do.
Also if using generic/bad quality printheads "not designed" for solvent/corrosive inks might be the head. (maybe you should try with another printhead if you have one).
To check if pump is working good, open the pump/cleaning area cover.
And make a hard wash. if the tubes connected to the pump vibrate strongly it means that all tubes are in good condition and pump is making good vaccum.
Also you may want to hear if there are strange noises in the pump (remember that jv33 pump is mechanic, something inside could be broken and not making enough vacum, bur if tubes vibrate there is no problem)

To check if captop is bad, replace the pump job with a sryinge. To do this.
You must stop 1 of the 2 exits with a piece of tube with a plastic seal on it so ink can go through.
And absorb with a sringe through the other tube. (you will be albe to see like Black ink (not really black its CMYK all together)
If printhead stays attached with cap top and its hard to detach when pushing it(you must do this in funciont St. Maintanance=> Carriage out), cap top is in good shape. also you may want to clean captop station (complete not only captop), believe or not helps a lot.... (i use only water for aqua-based ink) there are 2 or 3 screws in it no need to take only the captop.

if any other thing i could help send pm or just ask here.

 

[MikeD]

looks like the hose in reference was not allowing enough wash to get into the capping station. I swapped out the hose and all is well!!!
Thanks for all of the insight!