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Suggestions Discussion Nozzles are clogging but tech said there's no need to replace cap top

Discussion in 'Mimaki' started by Lady Who, Dec 8, 2019.

  1. Lady Who

    Lady Who Member

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    Dec 8, 2019
    Brazil
    Hello there!
    I've had a Mimaki CJV150 for about 20 months now and lately I'm having issues with the head nozzles, and it got worse in the last month (see attached test print please).

    Mimaki technician came to check this and he only replaced the wiper. According to him (and to the tests he did), there's no need to replace the cap (it's never been replaced by the way) because it's sealing properly (so he says). I always do all the routine maintenance and cleaning, already tried the head cleaning functions a couple of times (normal/hard/ultra), fill up ink, and did a 5 hour nozzle wash with no improvement in the results. I only use Mimaki original mild solvent ink, original wiper and stuff. Tech said there's nothing that could be done to improve it neither to stop it from getting worse, that I'll need a new head soon and this is probably happening due to low use.

    I don't wanna try the syringe process because I can't afford another printhead right now if something goes wrong, but I do believe there must be something I can do to prevent other nozzles from clogging. As you can see, the problem seems to be very specific with magenta lines. Tech guy said that if the capping wasn't sealing properly, nozzle clog would be in all other colors too.

    I print few stuff, like one hour a day. And no parts were replaced yet (except wiper).

    What do you guys think? Is it good idea to do overnight soak every day from now on, to avoid more clogging? Do you think changing the cap may stop worsening this issue?

    Thanks in advance and greetings from Brazil!
     

    Attached Files:

  2. smilecth

    smilecth Manager

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    I'm not a pro but I think there could be the tube line problem. If only magenta color had a problem, there could be a leak along the tube line from cartridge to head nozzle.
    At first, if I were you, I would check the tube line.
     
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  3. Solventinkjet

    Solventinkjet DIY Printer Fixing Guide

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    The cap top should be changed once per year regardless if it's sealing or not. Usually when I change it I also flush the pump tubes to make sure they aren't clogged. Your dampers should also be changed once per year but a lot of people go years before changing them. It's worth a shot in your case. If you bought the machine new, that head should last 3 to 5 years and sometimes I see them go 10 years. It sounds like your tech might not be very experienced. Also, look up the nozzle replacement function in your manual. You can replace missing nozzles with other ones up to I believe 10 nozzles per channel. You definitely have options.
     
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  4. Lady Who

    Lady Who Member

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    Right, thank you. But you think I should also change the dampers or only cap would do it? About the dampers, tech said time ago there's a huge risk of permanently damaging the printhead when dampers are changed, so, they only recommend changing it when changing prinhead and then, change stuff altogether ( printhead + dumpers + captop). And yes, I bought the machine new and never thought the head would have problems so soon.

    Thank you all very much! I'm taking action and will keep you posted. All comments and ideas are still welcome and I'll be back to mention everything that I've tried.
     

    Attached Files:

  5. woolly

    woolly Active Member

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    i am a roland person so cant work out which way up the head pic is, guess was done with a mirror .
    on the two outer rows of nozzles both magenta is residue which may correspond with the missing nozzles, looks like the head has rubbed a lot and the wiper not clearing it away. on the left of that pic you can see the track mark of the capping rubber which would indicate its sealing cant make out the right hand side.
    time for a new cap top anyway due to some cross contamination and other defections. just my observations for what they are worth
     
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  6. ChicagoGraphics

    ChicagoGraphics Major Contributor

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    I had the samething happen to my JV3, their was something blocked in the ink line and after flushing it out and changed the damper it worked good as new.
     
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  7. Neil

    Neil Member

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    Things you can check yourself -
    when the machine does a clean, do you get much ink on the wiper?
    Is the ink in the middle of the blade?

    If you don't get much ink, it is probably the cap top that needs cleaning or replacing.
    Also clean under the head so it makes a good seal. I use a small brush with cleaning solution to wipe the bottom of the head, and then wipe and clean around the perimeter of the head to get rid of any built up ink.

    If the ink on the wiper is off to one side, you need to align the wiper blade so it is lined up with the printhead.
     
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  8. Jim Hancock

    Jim Hancock Member

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    I agree with Solventinkjet's observation. Your tech definitely needs some more experience - "tech said time ago there's a huge risk of permanently damaging the printhead when dampers are changed", as this is absolutely untrue, unless the tech is clumsy and breaks the nipple on the head manifold.
    Also, please use only foam swabs dipped in cleaning solution on the bottom of the head, and very gently. A brush can possibly damage the nozzle openings.
    Definitely change the cap top and the wiper, if it isn't new. There are also wiper position adjustments as part of the capping adjustment, as wiper misalignment with the head could cause something like this.

    Regards,
    Jim
     
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  9. Lady Who

    Lady Who Member

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    Dec 8, 2019
    Brazil
    Thanks Neil, very good observation. Here it goes a photo of the wiper after cleaning. It was replaced on the beginning of november
     

    Attached Files:

  10. Lady Who

    Lady Who Member

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    Hi, I'd like to thank you all for replying. I've requested the tech to replace the captop the other day, but he was out of the office in the 2nd week of december and they're all on vacation since last week until jan 6th, so, I was going to get back to you only in January.
    I was patiently awaiting because things were working fine, but now, after the machine sitting for 2 days (with power on and doing refresh every hour), a whole magenta line disappeared!

    I'm wondering...
    1) Why deflected nozzles come and go, how's that possible? I thought once a nozzle was deflected, it could never be recovered

    2) 3 nozzles on the left cyan line were clogged on december 22th and didn't got back after nozzle wash, but today they're back

    3) Do you think I could get those nozzles back and the magenta line back after replacing the cap next month or the chances are lower the more time I wait?

    I'm now doing a head soak, I'll leave it for about 5 hours
     

    Attached Files:

  11. Boyanski

    Boyanski Member

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    When all inks are on 1 head only and there is 1 ink cap its pretty simple math. Obviously pump sucks and ink flows. Magenta does not flow so well as other inks compensate. The other inks flow more easily than said magenta. So its not a cap or sealing problem. Its a head, damper, ink lines or connection problem. Whatever else the tech says. What tech he is, afraid to take your money and change a stupid damper...

    Instead of soaking and messing around- why don't you clip all other colors to stop ink flow and then suck manually or do head clean. And if you use a head clean then take out waste line in a visible clean bottle to see what pump throws out. No need if you suck using a syringe from the line from the cap right before the pump.
     
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  12. Lady Who

    Lady Who Member

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    Dec 8, 2019
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    Yeah, I get what you're saying, I'm still learning how this thing work by reading a lot here. As for the tech I think that must be a standard of the company he works for, not something related to his experience. He said it was the head and nothing could be done to get better, except trying to clean the head manually with a syringe, but it would be risky, anyways...
    I did a 5 hour head soak already with no change.
    I like your suggestions, but are there any risks of losing the head? The print quality is a bit lighter but tomorrow I'll try increasing the magenta density and see if I can keep printing with only one magenta line.
    Thanks a lot
     
  13. Boyanski

    Boyanski Member

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    I believe if you print with only one line and have other lines clamped you will burn the head.

    As the risk when sucking via syringe, i think there is not any risk as i have not heard of someone ruining the head that way. Its other matter if you push. Then probably you will ruin it.

    Probably best anyway is let the pump do the job, via cleaning. Just as i said, clamp all other hoses and check if at all the pump is doing anything, checking what the pump actually spits. In my printer i remove the wastage tank and use a towel there to see what the pumps are spitting/ i have 3 pumps, different head/ .

    You should carefully read your manual and service manual. To understand what ech cleaning cycle does. Then attempt what you are attempting to do.


    Basically you could use vertically a syringe full with cleaning liquid and open the push side, connect to inkline and inkline to your dumper or head manifold. Clip or close all other lines and using the different clean cycles clean your head meanwhile watching how it sucks the liquid. If you get what i mean.

    There are many ways to do that as you see, when you know what you are doing
     
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  14. Lady Who

    Lady Who Member

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    Thanks for the warning, never thought I could burn the head that way... so I'm out of business already. I've read the manual from cover to cover, but I'll try to find and study the service manual, because I don't feel ready to perform what you said at all. Or maybe I'll wait to ask the tech to do it for me in a few days. Only two days idle and a whole line is gone... this machine has less than 2 years, those printheads are practically disposable :(
     
  15. Neil

    Neil Member

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    It'll be fine, don't worry about it. Once you get a good seal it will come good.
    You really need to learn be able to change dampers, cap tops, capping stations and wipers by yourself.
    Then have spares on hand for when these situations arise.

    You can leave the head soak for a couple of days or more if you want.
    Clean the cap top and under the head, fill the cap, park the head, switch off the machine at the main switch and leave it.
     
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  16. Lady Who

    Lady Who Member

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    Dec 8, 2019
    Brazil
    Thanks a lot NeilNeil :) Yes, I'll get trained this next year, because it's too much agony waiting for the not available tech in the holydays and not being so sure the machine will be fine. You know, I'm a small wall decals e-commerce, this machine haven't paid itself yet and here in Brazil, those printheads are very expensive, like 30% the price of a new machine :(
    Are you sure leaving the head soak for a couple of days won't make things worse? I mean, the cleaning solution could destroy the membranes or nozzles, no? Won't the ink coagulate inside the lines if the machine does not run the refresh for such a long time? (this model refreshs every hour). These are the only reason why I haven't tried this yet, I'm afraid of making things worse.
     
  17. iPrintStuff

    iPrintStuff Prints stuff

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    Nah whenever we have a pesky nozzle out I tend to start a nozzle wash, fill the capping station with fluid, get the head seated then unplug it and leave it overnight. Usually sorts any problems.

    As far as your tech goes. Changing dampers etc may be daunting to you, but it’s something that’s pretty easily doable yourself so a tech should have absolutely no problems at all. If they genuinely said that changing a damper could break the head, they’re either incompetent or trying to scam you. It’s a very basic tech job.

    assuming your ink is all in date etc?

    as far as nozzles go, they can certainly come back. It’s just a matter of how they’re blocked/not firing. Obviously if you have actual damage on the nozzle it won’t work, but just air in the lines, blocked nozzle etc should usually be able to come back.

    As others have said you could try manually clean the head with cleaning solution and a foam swab but you need to be very careful to not damage the head. though this is probably the easiest thing you can do yourself other than a long nozzle wash.
     
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  18. Lady Who

    Lady Who Member

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    Dec 8, 2019
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    Thank you iPrintStuffiPrintStuff About the damper, this one tech said a replacement wouldn't fix my issue, since the problem is with the printhead. It was the Mimaki head office tech who said to me some time ago that the printhead could be damaged during damper replacement and that's why some techs don't recommend changing it unless it's necessary. I asked this tech at Mimaki head office why is that some techs say cap and damper should be replaced often and others say only when necessary.

    Yes, ink is all on date, original Mimaki, never used outdated ink. As for manually cleaning the head, I prefer avoiding it because, as shown in pics, there's no visible damage, just a few smudges that always disappear after a nozzle wash and the test print were good back then, even with smudges on the head.

    Checked the lines on the back and below the station, apparently no leak. I'm willing to check the dampers now... guess if there's something wrong could be seen at once, right? Going to do the homework
     

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  19. Lady Who

    Lady Who Member

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    Hi all, just to update: I got hold of the machine service manual today, and man, do I have stuff to read! Thank you all for the insights, you guys helped me a lot, and thanks to BoyanskiBoyanski who advised me to get the service manual, I think it'll make all the difference knowing how these machines work.
    And I'd like to share this great video: I won't flush my printhead this way just yet, but I think it's worth sharing. I'll come back with news soon (hopefully good ones).
    Happy new year and best wishes from Brazil :)
     
  20. Prairie Portable

    Prairie Portable Member

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    Where did you source the service manual? I have a CJV 150-160 and I'd love to have a service manual.
     
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