Mutoh 1624 - Missing Magenta

[J_Print]

Mutoh 1624 ValueJet

Had some poor magenta showing on nozzle checks, starting last week. I replaced the maintenance station (we were due for it anyway) in hopes that would clear it up. Following the installation, I achieved a perfect nozzle check. But after a couple prints and an automated cleaning cycle, the magenta drop out returned. Multiple manual cleanings and soaks, along with printing 100% magenta blocks have done little to improve the situation.

Could be due for a print head replacement or dampers (4 years with the originals). Just want to rule out as much as possible before springing for the new head.

Any advice would be appreciated!

 

[Solventinkjet]

Change your dampers first especially if you have never changed them. They are responsible for keeping proper ink flow to the head and when they fail you usually get ink drop out.

 

[J_Print]

Change your dampers first especially if you have never changed them. They are responsible for keeping proper ink flow to the head and when they fail you usually get ink drop out.

Thanks for the reply. Any damper replacement videos or guides you have seen floating around? I have a copy of the Service Manual manual and don't see any reference to dampers. The Solenoid Head Assy seems to match the dampers available on your site. Is that what I am looking for?

Haven't ever dinked around too much in the printhead carriage, so my experience in that area is limited.

 

[Solventinkjet]

Yeah they use fancy names now but those are the dampers. On our site they are called dual channel dampers. I don't have any guides but it's pretty straight forward although extremely frustrating the way it's designed and could be much easier in my opinion.

Disconnect the white connectors that are on top of the dampers and have a good amount of paper towel ready to catch the ink drops. It won't drip forever so if you just wait it will stop. I usually just keep the lines wrapped in the paper towel while I do the replacement. Then you just pull the dampers straight up and out of the head. They are not held in by anything other than friction. Once the dampers are out, check inside the head to make sure the rubber gaskets didn't get pulled off the damper and are still stuck on the manifold. Then wet the rubber gaskets on the new dampers so they slide on nice and smooth and reverse the process.

 

[J_Print]

I swapped out the dampers and got perfect nozzle checks after an ink charge! However, with a couple prints, the Magenta drop out is back. I'm resigning to a print head replacement, unless you got any magic for me.

 

[Pitzu]

I had exactly the same problem with Mutoh ValueJet 1614.
First time it was the maintenance station (one broken tube).
Second time it was the damper (it's advisable to use OEM damper...I had lots of problems with 3rd party dampers (some work...some don't))
Third time...it was...the ink?(probably a bad lot). I had to choose between the printhead or ink replacement. I've flushed the old ink with solvent and changed it with another ink.
If it was the flushing that helped..or the ink change..not sure...but worked great afterwards. We have 9 months without any incidents.