Mutoh VJ - 1614E - strange printing...

[FaneDuru]

We print on ValueJet 1614E since 2011. We used to have some clogged nozzles even we changed a printing head. We usually understand when and how is necessary to clean the head.
Now something strange is happening...
One rectangle of black ink nozzle check (the second one) started to miss lines. In this time the other one is perfect. I changed the damper but the situation did not improve at all. We called a local technician who cleaned that side of the had by spreading cleaner through the head until the jets were transparent and parallel. He used a syringe.
After that followed by inkcharge (little) the nozzle check was reasonable. I printed some tests which used to be also reasonable. The technician said the clogged nozzle will be better cleaned during a big print having black ink on the layout.
I started to print and printing looked reasonable. Even better after a while. But the strange thing is the next:
When I stopped printing I tried another nozzle check and the problematic black rectangle was very bad. I started printing again with the same layout but the printing quality was bad too. I did two strong cleanings and the nozzle check became reasonable again. The next printing was OK but after stopping it the nozzle check was again bad.
It looks like a kind of vacuum is crated inside of the head and when the machine stops the air goes inside that black region defusing that side in a way.
Do you have an idea regarding this strange behavior? Is it possible to have a clogged filter for that region of the head? Anyhow a little vacuum exists inside the head. This does not allow to ink dropping... But because of that hypothetical clogged filter is it possible to create a bigger vacuum making air to come inside the head, defusing it in this way?
Did anybody else face a similar situation? Even not, do you have an idea in order to help?
Thanks in advance!

 

[mantuasign]

I've been having the same issue with my printer, and the only thing that seems to fix is replacing the head. Have you had any luck fixing yours without replacing the head?

 

[unmateria]

I've been having the same issue with my printer, and the only thing that seems to fix is replacing the head. Have you had any luck fixing yours without replacing the head?

Nooooo. Dont replace the head. Its normal. If you want a quick solution you can solve in minutes, just replace the complete clean station, but usually is not needed. Do a strong clean and tell me if ink goes to the waste ink tank

Enviado desde mi Nexus 6 mediante Tapatalk

 

[mantuasign]

Nooooo. Dont replace the head. Its normal. If you want a quick solution you can solve in minutes, just replace the complete clean station, but usually is not needed. Do a strong clean and tell me if ink goes to the waste ink tank

Enviado desde mi Nexus 6 mediante Tapatalk

Unfortunately, all parts that could possibly be the culprit have been replaced, including dampers, lines going to the dampers, lines underneath the dampers, manifold, cap top, wiper, f2 fuse, subtank assembly, and ink cartridges. Use only mutoh ink, printer is always left on and maintenance station works as it should. Even mutoh is now saying head. Head is only a year old

 

[FaneDuru]

I've been having the same issue with my printer, and the only thing that seems to fix is replacing the head. Have you had any luck fixing yours without replacing the head?

I'm still using it but without that part of the nozzles...
I mean I transform (in Photoshop) CMYK in CMY with a specific color profile (testing a lot) and it is not any difference between original K and the one made from the other three colors. Of course the ink consumption for black side of the layout is bigger...
We could afford doing that due to the fact that we have other two machines in good conditions and split the jobs in a way to avoid much black on the layout.
Now we started to have a similar problem with Magenta and I'm struggling to find a solution. Just in order to better understand machine functioning and being able to apply what I learn to the other machines...
Now I'm afraid that we cannot avoid buying a new head, but only if I will not find a solution. Even a temporary one for didactic reasons...

 

[FaneDuru]

Nooooo. Dont replace the head. Its normal. If you want a quick solution you can solve in minutes, just replace the complete clean station, but usually is not needed. Do a strong clean and tell me if ink goes to the waste ink tank

Enviado desde mi Nexus 6 mediante Tapatalk

Firstly sorry for the late reply...
The cleaning station worked very well. A lot of ink was coming to the waste ink tank. I cut an old had and I could find a net inside the black side which I am sure it is clogged in ours. Theoretically this side can be dismantled and cleaned passing cleaning liquid in reverse direction. Using a pump, a filter and doing that for hours. But this side is attached to the real head through a kind of wooden screw which I did not dare to use it again without risking to ruin the plastic side...