Mutoh Cyan Nozzle & Print Issue

[ipusa]

Our Nozzle check is showing missing nozzels on both Cyan channels - about 50% of the lines are showing, but every time I do a nozzle check the result changes although roughly 50% are still missing. I've done about 10 head soaks, ink refill, replaced wiper (and I have a new cap top on the way). The re hasn't been any improvement in the nozzle check and all test prints of blue CMYK mixes are coming out purple.

Any ideas for what to try next? Replace the whole maintenance station?

 

[Solventinkjet]

Usually when the missing nozzles move around like that it means there is an ink flow issue due to an air leak or a broken membrane in the print head. The first thing to check is the ink line and dampers. I would replace the dampers and o-rings to see if that fixes this issue. If you see air in the ink lines, that is a good sign that the dampers and/or the connection between the ink line and damper is bad. While you're in there you might as well check the nipples on the head manifold. If they are cracked that will be the problem for sure.

If you get new dampers on there with no air in the lines and it still does the same thing, most likely you have a bad head. The older the head, the more likely that is the problem. You may even notice cross contamination in your nozzle check which would indicate the head as well.

There is a slight possibility that the maintenance station is bad but it is rare to have all of the colors working perfectly except for one where the maintenance station is the problem. If the nozzles weren't moving around like they are it would be much more of a possibility because clogging and not ink flow would be the issue.