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JV3 160 SP printheads driving me MAD!
Is it possible to have a broken printhead with all jets working?
I’ve been scratching my head all week and I cant come to any firm conclusion. i’m going mad over this and I hope there is some technical wizard who may have an answer.
Ok my magenta and cyan printheads seem to starve themselves it prints in a very odd way kind of patchy rather than banding. All dampers are brand new but after printing there are no nozzles blocked etc.
there isnt any deflection from magenta or cyan it just seems to not push out enough ink.
Any Advice would be greatly appreciated
Russ
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10 Replies
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I am far from any sort of expert on this subject, but…
are the dampers the right size?
some years back, when printing banners in a fast eco mode we had some issues. it was like ink starvation. we installed larger versions of our dampers by the same manufacturer and it solved our problem.
maybe not the answer here but maybe worth a thought. -
Thanks for speedy reply but it happens in all modes except 1440 by 1440 but I think it could be masked slightly by the high ink coverage, I may try using larger dampers though as its alot cheaper than the possibility of 2 printheads.
Russ
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yeh print heads are NOT cheaper, only seem to go up in price! 😕
we were pretty much stuck as to why we had problems also… as you say, if technical support from the supplier cant help then its maybe worth a gamble.
i remember another thing, different scenario though.
similar to what you said, nozzles all firing perfectly in print tests but ink starvation.
i took off the damper and had a very close look. on I think two dampers i had what i can only describe as ink that had "gel’d / solidified" and was sticking to the little filter in places on the damper. so plenty ink was getting through when the print tests were being made but when the machine was running prints and needing a fast supply of ink it was bottlenecking going through the filter as parts of the filter on the ]damper was clogged.
this required new dampers at £15 each which is nothing in caparison to what would have happened if that ink clot had got to the head.maybe worth having a closer look at those dampers out the machine to see if you have any grime on the dampers filter.
For low-cost dampers and the like try here digiprint-supplies.com
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I’m a big user of digi print supplies, I’ve also found a company called tech8 which supplies them in the UK at £540.00 which enables me to claim back VAT which if this is any use for anyone.
Russ
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also the is masses of suppliers in china selling them for 350 usd has anyone ever tried to purchase from any of these. I know it can be very dodgy buying for these sellars as 90% of them are scammers but was wondering if anyone had actually tried and found a reputable sellar.
Russ
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I doubt if replacing the heads will cure the problem if you don’t have a problem with a nozzle check. This is more to do with not enough ink reaching the heads. I would be looking for some sort of blockage or possibly a restriction in the tubing caused by something like a kink.
I don’t own a printer so can’t speak from experience but I do have a background as an engineer, have you done anything lately that may have caused this problem such as replacing parts ? -
The only thing that was changed was the inks and it had a complete flush out when i moved from itl ink over to eco sol ink tec inks. It printed fine for about 5 weeks which equated to approx 250 linear metres then this started to happen.
could dampers get blocked in 5 weeks. i have 3 dampers here so think i’m gonna change the magenta dampers to see if it makes any difference.Russ
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a damper can be clogged instantly, its what is being passed through it that dictates how long it will take.
a flush is flushing your existing ink out the system. your then feeding in new ink. but let’s say that the new ink has alien bodies in it that cant be filtered through your damper, then it will clog it. the clogging may not stop all the ink getting through, so print tests are fine. but may slow down the flow of ink when in full print mode.
i would check your manifold pins. check one or more hasn’t cracked.
this can happen when new dampers are being fitted because the solvent can deteriorate or make plastic brittle over time. -
I’m guessing that air could also get dragged into the system as well which would reduce ink flow, don’t know how you would check for it. If Robert says it is possible for the plastics to crack or split then this is something else that could start at any time.
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It sounds to me like everyone has pointed you in the right direction. But here are my thoughts:
Did you replace the o rings when replacing the dampers? This is a MUST in my opinion and I do that on every damper I replace in every machine.
Dampers can get blocked quite easily, particularly if two different ink types have been used, they can sometimes react with each other and create a horrible kind of sludge in the filter within the damper. It’s quite easy to tell by just looking closely.
There are also filters inside the head manifold which are not so easy to check. This fairly unlikely though if the lines were flushed out correctly.
Have you had any work done on the heads? I’ve seen JV3’s with 4 brand new genuine heads that print terribly. This can all be put down to head calibration not being done properly. The slant and unit adjust is critical on these machines so it has to be done properly with a minimum 25x loupe.
Try and get some samples up on here and we can form a more definite opinion as to what you need. At this stage, I would say that the print heads don’t need replacing.
Stafford
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