Clogged head Mutoh valuejet 1204 (I think)

[rlandor]

Hi,

I am having some questions for the pro's here

I have a Mutoh Valuejet 1204 and we do not use the machine very often here. The first months I let the printer always on standby, but I calculated that if I do not print anything it will take about a half year to run out of ink by cleaning cycles only (1/24h / eco mode).
So I decided to turn the printer off when not using it. Now that was a bad idea, because now when I want to print something I get banding in the black and the cyan colors. I already did a lot of cleaning cycles, but that does not help. I think the head is clogged.
Do you have any suggestion to remediate this?

I also would like to have a service manual of the Mutoh if anyone has it.

Thanks a lot!

Richard.

 

[randya]

What does your nozzle check look like?

If you are missing nozzles you probably want to try "head soak".

 

[rlandor]

Hi Randya,

Thanks for the quick answer! Yesterday I tried the head soak by putting lint free cloth with cleaning solution on it under the head, and there is some slight improvement, but there still remains a line in cyan parts printed and A nozzle check reveals some missing parts in black.

I ordered a syringe and a bottle of cleaning fluid and want to try to clean the head by putting the syringe on the damper inputs. Now I am looking for instructions to remove the tubing from the damper. Have you ever tried this method?

I have searched everywhere for a service manual but cannot find it via google.

Thanks a lot!

Richard.

 

[randya]

The LAST thing I would recommend is trying to push solution through the head.
You can easily damage the piezos and/or blow out the dampers.

You want to pull.
Head soak, and pull a vacuum on the bottom of the capping station.

 

[rlandor]

Hi,

The reason I came up with the solution is because of the instructions found on this page:
http://www.digiprint-supplies.com/blog/227-printheads

Especially this part:

Print quality issues


Problems occurring with Print heads drying up and causing blockages to the nozzles, this does not necessarily mean installing a new print head which is costly and may sometimes be unnecessary to do. An easy fix and solution to this problem is detailed below:


With the carriage locked in home position and the heads capped.
Take a clean syringe, and fill it with a clean solvent solution.
Attach a male adapter to a syringe, (used to connect the pump tubing), as this fits perfectly into the top of a new damper.


Carefully remove the damper from the troubled print head, with the syringe attached to the new damper push onto the manifold on top of the print head. Gently push the plunger on the syringe, until you can see the blockage clearing from the print head through the tubing that connects to the pumps. Be careful not to apply too much pressure there are filters in the actual head and to much pressure can cause issues. The same thing can be done by connecting the tubing from the syringe directly onto the manifold this should only been done once you have experience of doing this.


Do this until the solvent becomes clear going through the tubing of the pump. It can sometimes take a couple attempts. If the solvent goes through to the pump tube you can be sure that the manifold, head, capping station and pump are clear of any blockage. If after a couple of attempts nothing is happening you need to isolate where the actual blockage maybe.



This can only be done with the heads disengaged from the capping station. Once the head is uncapped ensure the printer is switched off and the power lead is removed this mainly applies to the large format printers and not the Grand format. This is to avoid any possibility of causing problems to a main board if you disturb ribbon cables that plug into the print head.
Move the carriage to a comfortable position to work on and place lint free material under the print head to catch the solvent. With the damper removed attach the syringe to the print head and gently push you should feel no resistance and the solvent should jet out of the bottom of the head. Look at the base of the head whilst doing this and you should see a nice curtain of solvent from all the nozzles. If this is good move onto the capping station.


On the capping station, disconnect the tube at the pump end place some lint free material on the bottom of the tube and using a pipette place some solvent on the cap after a short time this should drain away. If it drains away move onto the pump.


Place the syringe onto the pump tube and gently push this should push the solvent through to the waste bottle.
When doing this always complete the process as quick as you can and never walk away and come back. Because the carriage is not capped leaving it uncapped for a long time could cause other heads to dry up and become blocked. Also if you are unsure of any of the above process do not attempt it, get an engineer to check it for you.

They also sell equipment to do this:
http://www.digiprint-supplies.com/DX5-Head-Cleaning-Kit-p18140.html


Do you think that's too risky?


Thanks!

Richard.

 

[randya]

Very LAST thing I would do.

I mean if you are going to buy a new head, there is nothing to lose.

Otherwise, pull through the cap. IMHO.

 

[ABHDesigns]

I would suggest that you do another head soak. I just completed my first the other day with amazing results. Crack open a cleaning cartridge and let it sit over night. Good Luck!