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UCJV300 1 White channel goes missing

InkHead

New Member
Trying to solve an issue with our UCJV300 that has the WWCLCL setup. A few months ago, we started having issues where 1 white channel (Channel 7) goes completely out or most of the nozzles go missing. I do a few cleans and they come back and later in the day if I do another test print, the same thing happens again. Here is what we have done to troubleshoot and try to resolve the problem.

1. Cleanings and nozzle washes
2. Had a tech come out and we thought it might be the head so the head was replaced under parts warranty.
3. We also replaced the subtank for the head we replaced.
4. Replaced the captop assembly for head 2
5. We adjusted the positive pressure to be within spec.

Seems to have worked for a week or two and now the same thing is happening again. The same exact white channel goes missing completely or the majority of nozzles are missing until I do a few hard cleans, etc.. All other channels are firing fine even the 2nd white channel.

Any recommendations on what I should look into next. Is there some kind of vacuum leak? A valve or something for this channel that might be causing this issue?
 
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balstestrat

Problem Solver
Hmm I don't know about this particular model but on some Mimakis the printhead cable can go bad and needs to be replaced. Maybe it was already done with the new head or it doesn't even concern this machine?
 

InkHead

New Member
Hmm I don't know about this particular model but on some Mimakis the printhead cable can go bad and needs to be replaced. Maybe it was already done with the new head or it doesn't even concern this machine?
I'm not sure if any cables were replaced to be honest. Kind of looked like they removed the subtank, removed the head and put the new head in. Unless the head already has a new cable attached to it, I don't think anything else was replaced. I'll contact my tech and try to find out.

Would there be a cable for each channel on the head? Both clear channels and the other white channels are firing just fine on this head.
 

Solventinkjet

DIY Printer Fixing Guide
New heads come with cables attached so that should be fine. It definitely sounds more like an ink flow issue to me. How old is this machine? Newly installed or has been running for a while? Are you getting any sub tank or ink supply errors?
 

InkHead

New Member
New heads come with cables attached so that should be fine. It definitely sounds more like an ink flow issue to me. How old is this machine? Newly installed or has been running for a while? Are you getting any sub tank or ink supply errors?
Machine will be 2 yrs old at the end of July. no sub tank or ink supply errors. We did replace the subtank for this head when the head was replaced since we were already in there but it never threw any errors even with the old subtank

As far as flow issue, do you think the hose from the ink bottle to the head should be changed? How about the ink ball valve that gets pushed in when dropping the ink bottle in? Just trying to brainstorm here...
 

Solventinkjet

DIY Printer Fixing Guide
Machine will be 2 yrs old at the end of July. no sub tank or ink supply errors. We did replace the subtank for this head when the head was replaced since we were already in there but it never threw any errors even with the old subtank

As far as flow issue, do you think the hose from the ink bottle to the head should be changed? How about the ink ball valve that gets pushed in when dropping the ink bottle in? Just trying to brainstorm here...

I had a customer who ran a machine with white but didn't use the white as much as he thought he would. Over the years he had a similar issue where the white stopped working and it did end up being a clogged line. I replaced it and it fixed the issue. So it is possible for sure. You technically should get a sub tank error if this is the case however as it wouldn't fill and so the senor would never indicate it being filled. It might be partially clogged however which would make it fill slowly which could cause your drop out issues.

I don't think it's the ball because you would get an error basically saying there is no ink in the tank if that were the case.
 

InkHead

New Member
I had a customer who ran a machine with white but didn't use the white as much as he thought he would. Over the years he had a similar issue where the white stopped working and it did end up being a clogged line. I replaced it and it fixed the issue. So it is possible for sure. You technically should get a sub tank error if this is the case however as it wouldn't fill and so the senor would never indicate it being filled. It might be partially clogged however which would make it fill slowly which could cause your drop out issues.

I don't think it's the ball because you would get an error basically saying there is no ink in the tank if that were the case.
We do use the white ink but not nearly as much as CMYK or even clear. So I'm willing to swap out the line. Is this something pretty easy to do? I'm pretty handy and work on electronics and such all the time.

Do you happen to have a part number for the line by any chance?
 

Solventinkjet

DIY Printer Fixing Guide
We do use the white ink but not nearly as much as CMYK or even clear. So I'm willing to swap out the line. Is this something pretty easy to do? I'm pretty handy and work on electronics and such all the time.

Do you happen to have a part number for the line by any chance?

P/N M018909 - $104 for 10 meters. We also have an aftermarket line for $2 per foot if you're interested.

For me it was pretty routine. I simply butted the new line up with the old line and taped it so it was as close to being a single continuous line as possible. Then just pulled the old line out and the new line followed behind. That's for the main long piece of line, there are also some smaller lines near the bottle holder and the circulation route. I tested those out by disconnecting both ends and trying to pull air through with a syringe. If it gave a bunch of resistance, I changed it. You do want to be careful though. There might be liquid ink in the lines in which case you will want to suck it out with a syringe if possible. In my case it was so clogged that there was no liquid in there. The main concern is just not getting it on any electronics.

Once the new lines are in, I just pulled ink into the line with a syringe near the sub tank and then attached the line to the sub tank. Then you run a sub tank fill and it should do the rest for you. You will need to do an air purge after this.

Edit: Also, I'd run all this by your tech. You don't want to do it if you are still under warranty.
 

InkHead

New Member
P/N M018909 - $104 for 10 meters. We also have an aftermarket line for $2 per foot if you're interested.

For me it was pretty routine. I simply butted the new line up with the old line and taped it so it was as close to being a single continuous line as possible. Then just pulled the old line out and the new line followed behind. That's for the main long piece of line, there are also some smaller lines near the bottle holder and the circulation route. I tested those out by disconnecting both ends and trying to pull air through with a syringe. If it gave a bunch of resistance, I changed it. You do want to be careful though. There might be liquid ink in the lines in which case you will want to suck it out with a syringe if possible. In my case it was so clogged that there was no liquid in there. The main concern is just not getting it on any electronics.

Once the new lines are in, I just pulled ink into the line with a syringe near the sub tank and then attached the line to the sub tank. Then you run a sub tank fill and it should do the rest for you. You will need to do an air purge after this.

Edit: Also, I'd run all this by your tech. You don't want to do it if you are still under warranty.
Sounds like a pretty simple task that I can do. I checked on your website and did not see the part number. I would probably just do the OE. Are the little clamps reusable or do replacements come with the tube
 

Solventinkjet

DIY Printer Fixing Guide
Sounds like a pretty simple task that I can do. I checked on your website and did not see the part number. I would probably just do the OE. Are the little clamps reusable or do replacements come with the tube

The clamps are reusable. Unless they have physical damage, I'd just use the ones you have. Give me about 10 minutes and I'll have them up. We're a little behind adding parts to the site due to some technical issues.
 

Scotchbrite

No comment
Is there something that can be done to help prevent the white from getting clogged? Like printing some sort of gutter or something?
 

Solventinkjet

DIY Printer Fixing Guide
Is there something that can be done to help prevent the white from getting clogged? Like printing some sort of gutter or something?
The machine does have a recirculation route that is supposed to agitate the ink inside the system to prevent the clogging. For some reason if the white doesn't get used enough, it clogs in the lines though. The lines are black and UV resistant but the ink still clogs. So it's not clogging in the head as much as it's clogging the line. Technically it shouldn't happen but it does for some reason. The gutter printing would help with drop out during printing though.
 

InkHead

New Member
Wanted to post an update here after replacing the tubing for the white ink channel that was dropping nozzles all the time. I was successfully able to replace the tube (not too difficult at all) and the next day, all the nozzles were firing and I did not have any missing nozzles. Typically the issue would manifest it self after a few hours of inactivity and printing a test print would again show the nozzles were missing. So a good sign!

The day after the successful test print, we did not use the printer again until today. So about 1 week of inactivity (This is the longest we have ever not used it as we typically use this everyday except weekends since we bought this machine 1.5 yrs ago). So this was a good test. Came in this morning and fired up the machine and did a test print and all nozzles are firing!! We may have solved this issue thanks to Solventinkjet

So it looks like the line was partly clogged this whole time. Will keep monitoring and if anything changes, I'll be sure to post back in here. Thanks for all the help and support Solventinkjet . Much appreciated!
 

InkHead

New Member
Well the issue is back. Channel 7 white was completely missing today. So maybe it wasn't a clogged tube.

Could it be some board issue or cable?
 

Ma_____

New Member
Did you have changed the black filter? (square filter after valve), perhaps the ink has settled in the bottle tank or in valve.
 
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