Luminous Landscape Forum
Raw & Post Processing, Printing => Printing: Printers, Papers and Inks => Topic started by: NackJich on October 02, 2023, 10:26:38 am
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Hello again..
I recently changed the belt on this printer, and the issue I have coincides with the procedure. On the left of my image is a somewhat crumpled copy of the pre belt change printer diagnostic sheet. To the right is a good example of the situation now where yellow is not coming through. There are no gaps in the assessment area, but the colour is way off. The central image with a magenta stripe down the middle should be "pure yellow." Is it the print head? I'm puzzled. I had expected the large coloured area to be solid, but half way down it breaks up into partly printed lines which makes me think printer head?
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NackJich,
I have experienced sudden color derangement (for lack of a better word) as the result of a foreign object blocking the drop sensor.
In my case it was a single very fine filament of cotton across the top of the sensor. Without a light and very close inspection it was not noticeable.
It happened after doing a routine internal cleaning and removal of excess ink build up on the service station wipers using tightly wrapped cotton swabs.
In case you need some direction; the drop sensor is the opening between the service station and the printing area.
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Thanks Charles. I'll take a look. The service station was filthy, was going to go back in and sort that out at some point..
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Something came back to me just now, and I think your advice is correct. As the printer booted up following the belt change, an error message appeared: Cleaning process needed. See clean the printhead drop detector in the user guide. I tried to understand it at the time, but the detector just appeared to be a narrow slot with nothing much to clean?
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The drop detector is just a small slot, with the sensor out of sight. It sometimes gets a bit of lint or a hair around the aperture that can cause problems. I don't think a color shift seems like a likely outcome, however. I'd be more likely to believe it is a faulty printhead. I've had a handful fail on me over the years, contaminating the colors. I'd clean the drop detector for good measure, but expect that you will need to do a head replacement if it is what I describe.
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+1 yellow is contaminated by Magenta its neighbour.
It happens.
Just replaced my GE/gray printhead for gray contaminated the Gloss
a New printhead will solve the issue.
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Yes it was the printhead. I have not come across the mixing phenomenon before! Yellow and Magenta are printing fine now. During the printhead installation there was the message Y and M ink cartridges need to be re-seated. Interestingly looking at the printer test sheet PG & LG seem remarkably similar. Wonder if that printhead is also bad (!?)
Thanks for your help. I'd be lost without this forum..
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Hi,
got the same issue but no solution. Changing printhead helps only couple of days.
https://forum.luminous-landscape.com/index.php?topic=125809.msg1055347#msg1055347
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My suggestion:
- take off the right side
- power off the printer (hard way) when the printhead moves to the left and the servicestation opens
- carefully clean the sponges and the rubber lips (attentention: this is messy)
- if this helps you should consider swapping the service station (watch https://www.youtube.com/watch?v=xUmtcqU3SEI)
cu
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My suggestion:
- take off the right side
- power off the printer (hard way) when the printhead moves to the left and the servicestation opens
- carefully clean the sponges and the rubber lips (attentention: this is messy)
- if this helps you should consider swapping the service station (watch https://www.youtube.com/watch?v=xUmtcqU3SEI)
cu
My thoughts too. When in maintenance or head cleaning mode the nozzles of both colors are squirting into the sponge, the inks should be pumped away through the sponge by the peristaltic pump in the maintenance station. If for some reason no underpressure is created (bad fit of the head on the sponge pad rubber, blocked tube to the pump, etc) then the ink can not get away and will enter the head side with the least pressure. Right now my backup Z3200 has that issue with the heads at both ends of the heads row. Which fits the theory of a reduced pumping capacity.
In a few cases heads can have an internal leak between the two color chambers. The difference shows when you print large areas with the two inks, after say two square meters, 22 square feet, the externally caused contamination (pump etc) will be reduced to an acceptable level. Not so with an internal leak.
Ernst, op de lei getypt.
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This problem with heads leaking ink from one chamber to the other is more obvious with M-Y than with par example- EG in Gray or Blue-Green especially when it is a subtle beginning leak.
At the moment i have a Blue- green head problem where green is contaminated with Blue.
At some point it is clear. a remedy can be printing lots of green to clean the green, but now that even does not help ( fast enough) anymore- so have to buy a new head. It helps to save old calibration targets to have a reference of what the colours should be.
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Please kers, report if the issue is coming back with a new head after some days printer in idle.
Thank you so much, Jaq
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Hi @NackJich, I realize this is an older thread but in case you encounter it again, or for anyone else having similar issue, first thing to do is weigh the head. A full head weighs 60 grams. Anything less than that has air in it, with say 57g and lower being "too much" air. Actually I recommend everyone weigh their heads periodically regardless of how well they seem to be printing, as a good health check.
In your case I suspect the Y side of the head was basically empty. Then during the printer's maintenance cycles or during headclean cycles, my current working theory is that ink from the M side gets into the Y side through the nozzles while it's on the capping station. Since it's flowing through the nozzles only a relatively small amount of M ink gets siphoned into the Y side, which is why the Y side isn't completely M-coloured. And of course it eventually runs dry during your test print because the Y side is mostly air and the ink delivery system can't cope.
Replacing the head is of course one option, but the reason it works is because the new head has no air. If however your printer has air in the ink tubes, then that may not last long! Recommend purging any air from the ink tubes at the carriage and adding new head seals (LPS's video and their purge and seal kit worked for me on 2 printers).
https://www.youtube.com/watch?v=bsZ1Dqye_Lo
It's also possible to also purge air from the heads and re-prime them with ink to work again (assuming the head isn't failed by now). I've posted recently on one way to do that.
Having examined the inside of these heads (see empty HP 70 MK-R photo attached) I'm not convinced that "leaks" between the 2 ink compartments is likely, although I know we're all inclined to speculate that could be happening. I assumed that was the case for years, too. But seeing how they are put together, I think it would actually require the head to be physically damaged with cracks in the plastic for ink to migrate between compartments. The more likely path of cross-contamination (path of least resistance) is from outside the head via the nozzles, as suggested above.
A good question is once a head has cross-contamination, is original print quality still achievable? I'm chipping away at that topic... I recently air-purged and ink-primed my Z3100 and heads and will be going thru print tests etc to find out. Certainly the attached MK-R photo shows some MK staining at the bottom of the R compartment. But whether that still results in "mixed" colours, and for how long, remains to be seen. I suspect it will work itself out fairly quickly since the volume of fresh ink now being delivered by the head greatly exceeds any residual from the earlier contamination. My plan is exercise the printer to see that the output looks stable, and then do fresh cal/profile.
I realize the "quick/easy fix" is just buy new heads (plus printer air purge), but that was much easier in the days long before HP started discontinuing products (HP 70 MK-R and R ink in particular) and rising costs + supply shortages for HP 70/73. And it's really frustrating (and silly) to be tossing a head with only a few prints from it because it got air into it. I'm fast becoming convinced that air really is the primary source of printhead woes/replacements, and by learning how to manage any air before it becomes a problem could make our heads last "practically forever".
Cheers
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Very promising! Thank you. As soon I have the time I will check it.
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Please kers, report if the issue is coming back with a new head after some days printer in idle.
Thank you so much, Jaq
no it did not came back:
my service station is clean...
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Thanks Kyle. Sorry I had not spotted your reply until today. It's an interesting theory. I've been weighing my cartridges for some time now. I'm more inclined just to change the printer head but they are creeping up price wise! However, If the problem occurs again within a short time frame I'll definitely have a go at the ink/air purge..
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Hi @NackJich , yes completely understandable to want to replace the head for sure, it's certainly easier. The key point tho is if there is still air in the printer ink tubes, then some may eventually find its way into the new printhead, and now your new printhead has the exact same problem as the one it replaced. In other words, replacing the printhead might only treat the symptoms (temporarily) without addressing the actual problem (air).
You might want to hold onto your old heads just in case, because HP is already discontinuing some (the HP 70 MK-R, and the HP 70 R ink, for the Z3100 are already gone, and I imagine the rest of the HP 70 / 73 line will not be far off). I suggest put the orange caps back on them and store them in a sealed bag.
Cheers