Mimaki CJV30 / Jv33 DX5 Printhead Issue - Magenta Stripe Appearing in Prints

[Plotter-FIX]

Hi everyone,

I’m encountering an issue with a DX5 printhead, and I hope someone here can help.

I’m a service technician and have personally replaced over 100 printheads, so I’m familiar with the process. In this case, I’ve ensured that the new head ID was properly entered each time.

I received a new printhead, but unfortunately, it seems to have an electronic problem. Here’s what I’ve done to troubleshoot so far:

1. Initially installed it in a Mimaki CJV30-130. After seeing a persistent magenta stripe in the prints, I replaced the cables, the mainboard (with parameters), and the slider board. Despite this, the problem persisted.
2. To eliminate the possibility of it being a machine issue, I swapped the printhead into a Mimaki JV33, and the same problem occurred—still showing a magenta stripe. Other Printhead from JV33, no problem in CJV30-130.

I’ve attached images of the problem.

Additionally, here’s the head ID for reference: 37A783D3-D5557RSV-0WSSUK0G. I always put the HEAD-ID, so that couldn´t be the problem.

Before anyone suggests that it’s an incompatibility because this is a Mutoh printhead, I want to clarify that we’ve been using Mutoh DX5 heads in Mimaki machines for the last six months without any problems. We switched from Mimaki heads due to reliability issues and have installed around 50 Mutoh heads into Mimaki printers without a hitch, and they accept the head ID without any issues.

Does anyone have an idea of what could be causing this magenta stripe in the prints?

Thanks in advance!

 

[Solventinkjet]

I'd say it's a defective head which is very rare but not unheard of. Seems like it may have a short somewhere telling that nozzle to fire all the time. We too have installed Mutoh heads into Mimakis for many years without issue. They're all Epson at the end of the day.

 

[Neil]

Damn. One rogue nozzle in that otherwise beautiful test print.

How far apart is that stripe in the print? Every 25mm?
Didn't Mimaki put something in their firmware that would print a stripe every 25mm if you used a non genuine head?
Not sure if I'm remembering properly, but it was something like that.

The remedy is to either downgrade the firmware, or, as I have done, alter some parameters to override the head checking.
Let me know if you need them.

 

[Plotter-FIX]

Hi Neil,

Could you please provide me with the parameters? I’d be happy to give them a try.

We’ve kept the printhead in our JV33 and installed a new one in the CJV30. We refurbish machines and sell them with a warranty here in Germany.

Thanks again for your support!

Best, David

 

[Neil]

PM sent. Although, looking at your test prints, it seems like there's one nozzle always on - as Solventinkjet said.
You can see that it fires even over the media clamp.

It's like you'd need to plug it up, but then what would be happening inside the head?