CJV 30 Sudden Magent and Cyan Loss, ODD...

[121a]

Hello all,

Just replaced the cap station in this machine. I figured the OEM one has seen better days and the seal started to fail on it, resulting in a dry head after a weekend of sitting. After two weeks of taking 90 minute head soaks on Mondays, I ordered a OEM cap off eBay. Replaced it yesterday and tested the connections/drains. All seemed fine. Soaked the cap in washing liquid. However, I didn't get a chance to run ink through the new cap station. So this morning, the entire head was dried. 45 minute custody wash resulted in a perfect test print.

Now comes the strange part. To saturate the cap station, I did an "Ink Fill Up". Ran another test print. Missing far left magenta. Soaked the head again. Now missing all magenta. Another ink fill up. Missing the Cyan. Only the yellow and black are printing fine. Nothing comes out of the magenta and cyan. Two days ago, perfect prints. In the matter of less than 60 minutes, I only have two colors.

Not sure if the dampers are needing to be replaced. Not sure what is going on. Ink appears to be in the lines. I followed the JV33 capping station replacement guide, very easy. Head itself appears to be fine. Nothing stuck to it. I have a feeling the ink just isn't going through the lines but I have no idea. Luckily, this is happening during a lull in printing. Any help would be appreciated.

Dampers

Test print

*edited for adding photos*

Thanks
Ryan

 

[Solventinkjet]

I would test the pump first to make sure it isn't clogged. Even if the cap drains, one side may be clogged and that will cause the issue. Use a syringe to push solution through each waste tube into the waste tank. If it doesn't flow all the way through, try to work it so you can break up the clog. I can see Cyan in the Magenta damper which means the damper could be failing but usually I see this when the cap top is bad or the pump is clogged. Also, make sure you put the blue stopper on the third hole in the cap top. If that is not on, it will cause problems.

If the pump is not clogged, I would move on to changing the dampers. It is possible that they are clogged or malfunctioning in another way. If the pump pulls on the damper and nothing comes out, when the pump stops pumping, the damper will suck some of the ink in the cap top back into it. This could cause the cross contamination.

One thing I always check to be sure is that the ink cartridges have ink in them and not empty. Sometimes a cartridge will fail and not flag the machine as empty and cause this issue. I would also check the valves in the back of the cartridge holders to make sure they are opening and closing properly. If not, ink will not flow through.

Something else that may be happening is the pump is just too old and not pumping as hard as it should on one or both sides. If you try everything and it still doesn't resolve the issue, change the pump. If it is older than 2 years, change it regardless.

 

[121a]

Thanks for the quick response! As of now, I swapped in the original cap top. The one purchased from eBay had a stopper on it and the OEM cap has the blue stopper. Definitely didn't forget that. I just find it incredibly odd that the first test print of the day, after the cap top was replaced, resulted in NOTHING. A cleaning resulted in a PERFECT test print. Now I only have two channels firing.

Inks are all full. So its not an ink issue. Ink is in the lines from the print cartridges to the dampers. Looks solid too, no gaps or air bubbles.

The pump you are referring to is the capping station pump, correct?

The machine is essentially stock Mimaki going on 3 years. Only part that was replaced was the cutting head data cable (1 year ago). We switched to 20/20 inks about 2 months ago from Mimaki (since Grimco stopped carrying the OEM inks). Haven't had an issue with the inks.

I'm going to get a syringe and attempt cleaning the pump. For now, I am going to let the machine sit with the washing liquid in the cap top and off. Tomorrow I will attempt cleaning the pump and then go from there. Seems like I should replace the dampers too as they are probably at the end of life. May also replace the pump as suggested.

Any other ideas or suggestions?

 

[Andy D]

We lost a couple heads on our test prints a while back and I thought it was the capping system needed to be replaced
but the tech that came in said it was a known issue with a Mimaki ink valve...maybe a anti-reverse flow valve?!?
I can't remember, but he bypassed it and our printer has been running like a dream ever since...

Edited to add: I talked to one of my guys that was up there at the time and he said the tech called them "floater" valves,
and that he said they are unnecessary and do nothing but cause issues so the tech took them out...

 

[121a]

^
Do you know where those are located?

No improvement since yesterday. Washed the pump as well with 10ml of wash fluid. Any other input is greatly appreciated. Thinking we are going to replace the dampers and pump then call a tech if this doesn't fix the issue.

When trying to print a full color image, only yellow and black...

 

[Andy D]

I asked my guy and said it was located right above the print heads and that the tech cut them out and
hooked the hose right up the the print head.

If I remember right it was just a little round piece of plastic with a float ball inside.

I googled it and I think it's like this, but I'm not sure:

 

[Solventinkjet]

I asked my guy and said it was located right above the print heads and that the tech cut them out and
hooked the hose right up the the print head.

If I remember right it was just a little round piece of plastic with a float ball inside.

I googled it and I think it's like this, but I'm not sure:

Do you have a picture of this setup? I am interested in seeing what your "tech" did as hooking the ink line up directly to the head would result in a major failure. In my experience on these machines as a certified tech, there have been no field recalls that involve removing a part from the machine to make it work better. It sounds like your tech got stumped and rigged something up that luckily worked. Still, I would be concerned if he took the dampers out and somehow got the head to fire. The dampers have filters in them that protect the head.

 

[Andy D]

Do you have a picture of this setup? I am interested in seeing what your "tech" did as hooking the ink line up directly to the head would result in a major failure. In my experience on these machines as a certified tech, there have been no field recalls that involve removing a part from the machine to make it work better. It sounds like your tech got stumped and rigged something up that luckily worked. Still, I would be concerned if he took the dampers out and somehow got the head to fire. The dampers have filters in them that protect the head.

I don't have a picture but it just so happens that I need to work on the machine tomorrow and will try and get a picture.
All I know is several of my heads were not firing and he told me right of the bat what it was, made his changes and the
printer has been working great for almost a year now.
He could have told me it was the capping station and/or print heads to jack the price up and we probably would have know any better.
As it was it was a cheap and quick fix... My printer is a Mimaki JV34-260 BTW

 

[121a]

VanderJ, I placed the order with your company and hope to see my order next week. I thank you for all the help thus far. Really hoping this is an easy fix as we are getting calls for prints and don't have a secondary printer to use! I don't know what a bad or a good damper looks like so I'm just hoping that is the issue.

 

[121a]

Replaced all the dampers, clamp connections and the ink pump. Still no go. Test print results in nothing. Pulled ink through the damper with a syringe and it comes through but with a bit of resistance.

Any further help is greatly appreciated.

 

[SightLine]

Replaced all the dampers, clamp connections and the ink pump. Still no go. Test print results in nothing. Pulled ink through the damper with a syringe and it comes through but with a bit of resistance.

Any further help is greatly appreciated.

If you syringe pull from the damper or ink lines on a JV33 you must first open one of the ink valves behind the cartridges for the color you are pulling on. There will be heavy resistance if you don't as you will then be attempting to collapse the ink lines and damper.

In my experience a nozzle soak is as good as anything at opening up stubborn nozzles on these. Anywhere from 10 minutes to as much as an hour will generally get things flowing again. Vander has some good suggestions and knows these machines well. I'd be checking the pump and also checking to be certain that new capping top does not have any nicks in it. Also as Vander mentioned you want to be certain the ink valves (back of the cartridge slots) are opening when they should be. You should hear them click when they open and can manually open them in the #TEST service menus.

 

[121a]

Alright, so even after pulling ink through the dampers (no obstructions or breaks in the lines from the cartridges to the dampers, we were stumped. Called a tech out and he fixed the issue on Friday.

We couldn't really pinpoint one exact cause for this mystery though. The most we could figure was the capping station wasn't aligned properly. This allowed the ink pump to just suck in air and not pull ink through the head. Even after replacing the capping station top and the ink pump, the tech said the pump we ordered may not be strong enough. He suggested ordering a Mimaki pump and not one that matches the OE specs. So we have a pump on order with a supplier in IL.

Even after diagnosing this and determining that the head is in good condition, he flushed it with cleaning solution to check/clear any built up ink. He also "burped" the dampers to fill the head with ink. After doing all this, he still couldn't get one yellow channel back. The most he could figure was it was electrical. So he set out putting in new cables to the head. Sure enough that solved the problem, the left yellow channel was back.

Being the smart A that I am, I said once he installs the original cables (the cables he had were for the 60" model, we have the 54"), I said now it shouldn't work. Negative. The yellow channel was firing even with the original cables. So, we figured maybe they just needed to be reset in the terminals.

However, we are still baffled as to why the sudden loss after replacing the capping station. I did manage to come up with a possible explanation. After replacing the capping station, the new seal allowed for a more air tight seal. After doing the initial ink fill up to saturate the new capping station, the new seal was so strong that it damaged the magenta damper (all the dampers were original to the machine; 3 years old). Then no matter what happened from here, whenever the ink pump would pull ink through the head, air would get in. Thus causing the odd but rapid progression of channel loss. No matter what we did, we couldn't get the channels back because of the air that may have made it into the system. After the tech adjusted the capping station, plus the new dampers and ink pump, he purged the system of air. And we are back to normal, with near perfect test prints.

What a story!