Cyan and Black on the left channel stop firing during production.

Maybe you'll need a new capping station. If the problem will come back shortly after a manual cleaning, then you'll have to replace that.

 

There's also an adjustment for head refresh rate you should check. It determines how often the head returns to the capping station to refresh the ink in the dampers. Your long run may have depleted the available ink from the dampers until you did the cleaning.

 

I'm not sure what it should be set at, or even what printer you have. My JV33 is set the same as it was when it was delivered and I haven't had any problems. Your dealer should be able to walk you through changing it over the phone. If it was working correctly before, then changing the head refresh rate will probably just be masking the underlying problem.

Checking the dampers is always the first thing to check when you're dealing with ink delivery issues during printing. If the ink disappears after sitting for awhile then it's usually the capping station. Although an improper seal at the capping station can also cause the head refresh to work incorrectly as the pump won't be able to draw ink through the head to refresh the dampers if the seal at the capping station isn't correct.

 

It'd be something above the head, not below it.
Sounds like partially clogged dampers or something restricting the flow - causing ink starvation on a long run.

Being that 1 normal cleaning brought them back, the cap seal seems good.
As Rooster said: check the dampers.

 

What is the correct printhead height....MIamaki CJV30?

Hi again everyone, I replaced my printing head on my Mimaki CJV30-160 and I was hoping someone can tell me what is the correct height measurement without any media mounted?

 

Cannot remember for sure but I seem to recall your machine is a JV33 correct? If so there should not be ANY air in the dampers. Totally opposite of the JV3 which typically has dampers half full. Main thing I would check beyond that is the head refresh rate. In Flexi you can set the head refresh rate job - on jobs with very heavy ink coverage I do generally bump the refresh up to two to make sure it does not starve for ink. On Flexi on the driver tab when sending a job - you can set the refresh from 0 (no refresh during the job) to 3. Typically we leave it on 1 all the time but on the heavy coverage jobs often bump it to 2. I've never used it on 3. I imagine you can set this on the control panel as well.

 

My guess is you are having a pressure issue in the ink system due to the air in the dampers. On these machines (JV5 as well) the dampers shoudl not have ANY air at all in them. If there is there will be pressure issues when printing at high speeds or high ink coverage. It will probably work when slowed down and set the refresh high but it's going to be an ongoing problem. These are very sensitive the the pressure in the lines. I will also say from experience- getting the air out of the dampers is a major pain in the rear. I pretty much filled a big glass dish with washing liquid and using a syringe and tube dunked them - while holding the side valve on the damper open to get mine totally filled with no air when I changed the dampers on mine several months back.