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

Lady Who

New Member
Hello guys! This month I brought in another Mimaki tech. He changed the captop and seems problem is really the printhead.

Nozzles are not clogged, because he pressed the damper before printing a test and a lot of magenta dripped on the media when the carriage moved, but nozzles wouldn't fire at all. He disconected and cleaned the contacts in the electric cable of the head, but nothing changed. Also, he noticed magenta ink is mixing in the edges of cyan line and that's why he didn't even inverted the dampers: according to him, this mixing means that probably the internal chamber of the head is breaking and simply removing the dampers could break it all at once and I could not print anymore.

I asked him to do what you recommended Boyanski , he agreed at first but didn't do it because of that internal chamber issue with mixing colors that he detected after changing captop.

And a few days ago, I also lost that cyan line that was mixed with magenta (it was ok in the morning and in the afternoon, boom, no cyan!). Now black is beginning to mix with yellow, which makes me think that yellow will disappear soon. Back in december, I thought this mixing was due to a bad captop, but apparently it's something worse. This printhead is not even 2 years old and has less that 1 billion shots per line, can't believe this is happening :(

Dollar rate is high in my country, economy is bad and even if I manage to buy a new printhead, warranty is only 3 months and I'll be even more broken if I buy it and it starts to fail again in a year or two. I can't believe those printheads are disposable!
 

Boyanski

New Member
I don't know what to tell you. Are you sure the lines to the head do not have air? That they are full and dampers are full to the top??? He should have sucke air from dampers and make sure all till head is perfect.
As what you describe to me is a typical cartridge sealing problem, i know as i have it now on my printer. All is full and fine but auto cleaning does not suck as i have an air leak at cartridge. Fortunately i have separate heads for each channel so its easier to figure it out. Lines are full but cleaning will not work,

if i am at the point where you are, i will do what i told you. Clamp all lines minus one and one by one make sure sucking with 50 cc syringe or bigger that ink flows . Sucking from before pump and after capping. NOT PUSHING. Once you make sure that all lines are ssealed, no vacuum loss and ink flows through head, then make decisions
 

Lady Who

New Member
I don't know what to tell you. Are you sure the lines to the head do not have air? That they are full and dampers are full to the top??? He should have sucke air from dampers and make sure all till head is perfect.
As what you describe to me is a typical cartridge sealing problem, i know as i have it now on my printer. All is full and fine but auto cleaning does not suck as i have an air leak at cartridge. Fortunately i have separate heads for each channel so its easier to figure it out. Lines are full but cleaning will not work,

if i am at the point where you are, i will do what i told you. Clamp all lines minus one and one by one make sure sucking with 50 cc syringe or bigger that ink flows . Sucking from before pump and after capping. NOT PUSHING. Once you make sure that all lines are ssealed, no vacuum loss and ink flows through head, then make decisions

Hi Boyanski ! Well, the dumpers were full, he pressed it on the side and a lot of ink dropped on the media. He didn't check for air in the lines, but said it was a remote possibility. As you can see in test print, the lines start failing on the edges, then we have the color mixing and it's just a matter of time for it to disappear completely and it's not a clogging issue for sure. Tech wouldn't risk even switching dampers because he said there was a huge chance of breaking the internal membranes at once and I could not print anymore. I believe he's right because air in lines wouldn't explain this color mixing. He said probably the internal membranes are breaking and head is losing internal pressure, that's why those lines suddenly stopped firing.

Anyway, I can't try your suggestion and anything for now, because I'm still saving to buy a new printhead and can't risk mine just yet. I'm not even running weekly cleaning cycles or nozzle washing, unless if it's necessary. I'm writing a report to try to find out what I've done wrong to make this thing last so little. It's only 22 months today.
 

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Lady Who

New Member
I have heads on my printer with 18 billion count, never genuine ink and printing perfectly fine.
Yes, I totally believe you Boyanski. This other tech who came here said printheads lasts about 5 years, and can last even more when using original and high quality ink like this SS21 I use. That's why I'm writing a report to come back to discuss with you guys here, because there's something really wrong, I can't believe this is happening so soon
 
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