Replaced VJ1204 head.....now yellow will not flow solid thru lines? (bubbles)

[meltsner]

I just replaced our vj1204 printhead, the black was partially clogged and the head was over probably 5 years old. However with the new head, now during cleaning, yellow line(s) will pull ink through a little bit, then feed back to where it originally started. At first it seemed like a vacuum pulling it back. We have all the covers off, we've taken ALL the lines apart at all points, including at the cartridge, the small metal connector line, at the manifold (where the main line splits to two before the head), and at the dampers. EVERYWHERE is clear and free by blowing. Using a syringe at the dampers, ink will slowly come through, but at the manifold it seems to split into lots of bubbles.

Our ONLY conclusion after several hours of testing is that the dampers are not making a tight connection and is letting air in, somewhere. Yes we should have replaced them, and are going to order a set for the whole head tomorrow. It seems the only logical conclusion is that there is a leak allowing air in. We didn't touch anything else when replacing the head, except removing the necessary parts to do so.

Any other suggestions appreciated!

 

[RG]

Sounds like you are doing the right thing with new dampers. I would put on 8 new o-rigns, too. About the only other thing that could cause this problem is a crack in the post on the manifold where you push the damper down onto. But, this is very rare. If all else fails, you should use a syringe and back-flush cleaning fluid through the needle that goes into the ink cartridge of the problem color. I read somewhere that this needle can become partially blocked. This, too, is very rare.

 

[meltsner]

A super late thanks and update.....I changed my email and was unable to fully login/reply till I finally figured it out. Anyway printhead replaced successfully, new dampers/o-rings installed and it is now back and flowing like butter!!!! Glad the solution was that "simple".

 

[Dzignpro]

A super late thanks and update.....I changed my email and was unable to fully login/reply till I finally figured it out. Anyway printhead replaced successfully, new dampers/o-rings installed and it is now back and flowing like butter!!!! Glad the solution was that "simple".

What was the solution to your problem?

 

[meltsner]

What was the solution to your problem?

I've lost some of that memory by now lol, but I do think it was replacing the dampers that did it. Maybe not seating down correctly? Exactly why, I don't know, but it's been working since then.

 

[Dzignpro]

I've lost some of that memory by now lol, but I do think it was replacing the dampers that did it. Maybe not seating down correctly? Exactly why, I don't know, but it's been working since then.

Thanks for that quick reply!
I'm still using original dampers and printhead on my 1204A, 2008. I bought the machine from Signwarehouse along with a Graphtec FC7000-130 and the old style enduralam. All are still working. Except after the last maintenace station replacement I'm still with about 31 clogged black nozzles. Out of 360 of those black nozzles, missing that number of them still produces a great print. I've been doing head soaks on the maintenace station that seems to help. I think with enough head soaks 6 hours long each, I'll get them opened. I also suspect the dampers are clogged. Can you explain how you changed those. I've lost the jig to do the head wash with cleaning cartridges and plan on doing the ink discharge after removing the inks. I actually found a new jig, but not sure if it's that important. Signwarehouse still provides tech support via email and it's going good. Techie says to use a tube with a knot in it to attach to the ink lines after damper removal and once the ink starts flowing again, it should push any residual ink or cleaning fluid used through the head and maintenance station. I have been watching a lot of videos from Mutoh. The inks are supposed to be pulled out and shaken periodically. I bet the black builds up faster in tight corners if this isn't done. I only shook the inks before installing. If you have any recollection of how it went replacing the dampers and also the printhead, please let me know. Can't find a reliable tech as I scared one away when I came down with a flu, wasn't covid, I got tested, and he said he'd not be coming over anytime soon. Also, he want's to sell me his expensive parts instead of getting in the middle of my purchasing from another vendor if something goes wrong. So I'm doing it myself, and other than being with double vision, and not seeing depth correctly, the biggest problem is dropping screws and searching for them. I'm actually enjoying working on the printer, it's fascinating to me. I may end up doing tech work instead of signs someday.

 

[Solventinkjet]

13 years on a head is like winning the lottery, although I'm sure it comes down to your meticulous maintenance. You should be proud!

Dampers rarely clog but they do wear out and just stop pulling ink to the head efficiently. Mutoh recommends replacing them once per year but most people go until they fail which can be anywhere from 2 to 13 years! My best bet is you'll pop some new dampers in there and a new maintenance station but you won't recover the nozzles. The head is just too old and some or all of those missing nozzle are most definitely physically shut and unrecoverable. Still worth a shot to try to recover but don't expect a miracle!

 

[Dzignpro]

Thank you for those kind words. I'm not a major player in the sign industry and this machine as sat unused for weeks, and then months with the plandemic. I'm living 140 miles from it's location and noone to do nozzle checks or cleanings. I rarely did much maintenance, the rails have never been greased since from the factory for instance. I replace the maintenance station when it stops functioning and only three times have I done it, two of the times myself. Now, the nozzles missing vary and I'm confident most of the 31 missing black will return. I get great prints even with this many missing. 3 or 4 yellow and 1 magenta, and perhaps 2 cyans might not make it as the same ones seem to miss of those colors. Now, what procedure is used to change the dampers. I don't have access to a head locking jig, still looking for it. Signwarehouse suggests discharging the ink, but don't do the head wash, just get the new dampers and o-rings in place on the lines and connect them to the head. The ink recharging should move everything through as it gets filled again. Any suggestions as to what to expect when I start removing them, and I'll use a tied off spare maintenance discharge tubes for this to keep residual ink and air in place. In the mean time, I'm doing the head soaks until there's no more improvement. Then after the dampers, if it won't keep making satisfactory prints, I'll change the head. I'll be doing it myself as no tech wants the responsibility if my new parts I get from other sources fail.

 

[meltsner]

That's the very same printer/plotter setup we've still been using and going strong! Sorry about the late reply. Quite honestly, I don’t exactly remember the steps we took, apart from pictures I took. I don’t specifically remember having to clamp off the ink lines, but don’t take that as a recommendation not to . I think the dampers popped out and back in quite easily, and overall it was a fairly easy and very doable job for someone who doesn’t mind tearing into things.

 

[chris20630]

I never changed damper and o-ring myself on Mutoh vj 1614. I want to try because of bubbles in yellow line. Do you use original Mutoh? After changing, how is it filled or is it pre filled? Do I need a special syringe to fill?

 

[Solventinkjet]

I never changed damper and o-ring myself on Mutoh vj 1614. I want to try because of bubbles in yellow line. Do you use original Mutoh? After changing, how is it filled or is it pre filled? Do I need a special syringe to fill?

The way I do it on a 1614 is one connection at a time. So starting from the left damper I will disconnect the first connection, remove the old o-ring, install a new o-ring, and then connect it to the new damper. Then do the next connection and the next all the way through all 8. Doing it this way does 2 main things; it prevents ink from spilling out when you disconnect (although always have paper towel ready to clean up and little messes), and it keeps ink from flowing all the way back to the cartridge so you don't have to run a bunch of fill ups to get it filled again. 1 or 2 strong cleanings should do the trick if everything is working properly.

 

[Umca]

It maybe you damaged black inlet of the manifold while put damper. And, the air leaking there.

 

[chris20630]

Sorry, it's 1624 we have, 1614 was before, but 1624 is similar I think?

 

[Solventinkjet]

Sorry, it's 1624 we have, 1614 was before, but 1624 is similar I think?

Unfortunately Mutoh decided to make things more difficult on the 1624. You can't do one at a time because there's a cover that goes on and blocks you from popping the new dampers in if they already have ink line connected. In the case of the 1624 I usually make a little plug to put on the ink lines to keep them from dripping once they are disconnected. I use a piece of soft tubing that I tie one end off and just slide it onto the ink line.

 

[Dzignpro]

13 years on a head is like winning the lottery, although I'm sure it comes down to your meticulous maintenance. You should be proud!

Dampers rarely clog but they do wear out and just stop pulling ink to the head efficiently. Mutoh recommends replacing them once per year but most people go until they fail which can be anywhere from 2 to 13 years! My best bet is you'll pop some new dampers in there and a new maintenance station but you won't recover the nozzles. The head is just too old and some or all of those missing nozzle are most definitely physically shut and unrecoverable. Still worth a shot to try to recover but don't expect a miracle!

Hired a tech to come and install mutoh dampers. But, turns out they are ok and the printhead is bad. Looking for a new head with good terms for exchanging if it's a bad new part. I plan on leaving the dampers as is, and installing a new printhead.

 

[netsol]

Dzignpro,
You really should change those 13 year old dampers. The new head will thank you

 

[Dzignpro]

13 years on a head is like winning the lottery, although I'm sure it comes down to your meticulous maintenance. You should be proud!

Dampers rarely clog but they do wear out and just stop pulling ink to the head efficiently. Mutoh recommends replacing them once per year but most people go until they fail which can be anywhere from 2 to 13 years! My best bet is you'll pop some new dampers in there and a new maintenance station but you won't recover the nozzles. The head is just too old and some or all of those missing nozzle are most definitely physically shut and unrecoverable. Still worth a shot to try to recover but don't expect a miracle!

Thank you that reply. Well, I do clean around the head, the wiper, rinse out the sponge box and that sponge, and wipe around the capping station rubber seal, but that's about it. I keep a bed sheet over it when not using. I don't think this machine gets used as much as most shops.

I had a tech come and look this over. He determined the head was bad which quickly looses nozzles in the second to the left black, 180 group of nozzle firings. He determined this by switching the black lines to find the same group missing when printing a nozzle check. Does this make sense? First why do the nozzles even fire in the beginning after a short time of doing a little ink charge (while running this a few seconds, the tech pulls out the power cord, can this be done very often if at all?) and seeing nearly a full set print and then not firing after a few prints in only that left black quadrant. I just recently considered that the problem could be both dampers are bad, but then why just the left group of the channel seemingly affected. I should have replaced at least those two dampers. But they were going to cost 130 for the parts, Mutoh brand plus more labor time. I probably should have still done it. Also, I have 8 dampers included with a really cheap maintenance station from another vendor. But I've read in another thread they're problematic, or don't work and didn't feel safe then putting them in. Tech said I don't need the dampers, I believed him at the time, although he suggested a buy one or two as I told him I would buy a head from another vendor (haven't decided where to buy yet). He was there about an hour or two and with the trip cost included, 310. I'm super low on cash, literally almost broke and relying on my brother for funds to order the good parts. I live in Mexico if not working in the shop 130 miles north of the border which belongs to others. Maintenance station works when testing for ink flow with a piece of cloth placed in the waste box (really want a new one if those are still made somewhere). I see your head is about 220 dollars more, but maybe the remote tech support is better. Another gripe is the tech left the stabilizer cap off. I haven't printed since it was removed, and want to put it back on. I'm pretty sure I can handle that. He said his techs usually leave them off for how hard it seemed for him to extract it. We pulled the two black dampers twice. I think he pulled the cables off to get to the dampers, not sure. Not sure, been watching a lot of videos.

Please let me know how we could remedy this together, as I'm about to get funded this week to get this machine ready to make some income for us. Hope you're ok with that massive blaze going on.

Thanks Solventinkjet!