Kyocera 3051ci white lines Dev units going bad?

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

... I know this has been discussed already, but I'm wondering why this is happening? Is the developer just worn inside the unit? Has the develper simply lost it's magnetic properties for whatever reason?

In other words, by changing the settings that you're talking about, is this just compensating for worn developer?

I know you said something about machines with low usage, but in my case this is a high usage machine.

The developer doesn't lose it's magnetic properties, it loses it's tribo-electric effect ... that is static electrical properties ... when the resin wears off of the individual developer particles. If it lost it's magnetic properties it would just fall off of the developing roller, piling up in the bottom of the machine.

If quality is restored by a stir, it still can produce the tribo-electric effect, so in my opinion, not compensating for worn developer.

I don't have an adequate explanation for a high volume machine performing in this way. Perhaps they do long runs of K only, leaving the colors un-stirred?

... Edit: I know from back in the day that one way I used to compensate for worn DV to is increase the target value @ toner sensor. When the developer became worn, adding more toner to the DV unit would compensate for this. To, be honest, it always concerns me to run these new machines out of specs. Maybe it's just best to replace the DV units in question??

I'll agree on this. Increasing toner density just makes the machine run even dirtier.

Back when Mita developer came in bottles, not units, spiking the developer (adding a scoop extra) replaced some of the developer lost during normal usage, but typically did not gain you much time. Replacing that developer is the better choice.

No, when you select DV refresh, there's no option to select a single color. You can forcibly add toner to one color via simulation but I'd be careful with that as you have no way of knowing exactly how much to add and it could become way over-toned.

Correct. =^..^=

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

The developer doesn't lose it's magnetic properties, it loses it's tribo-electric effect ... that is static electrical properties ... when the resin wears off of the individual developer particles. If it lost it's magnetic properties it would just fall off of the developing roller, piling up in the bottom of the machine.

If quality is restored by a stir, it still can produce the tribo-electric effect, so in my opinion, not compensating for worn developer.

I don't have an adequate explanation for a high volume machine performing in this way. Perhaps they do long runs of K only, leaving the colors un-stirred?



I'll agree on this. Increasing toner density just makes the machine run even dirtier.

Back when Mita developer came in bottles, not units, spiking the developer (adding a scoop extra) replaced some of the developer lost during normal usage, but typically did not gain you much time. Replacing that developer is the better choice.



Correct. =^..^=

blackcat,

I enjoy our conversations and learn a lot. When I said, lost "magnetic" property, I wasn't talking about losing it entirely...only becoming weaker. I never heard the term: triboelectric effect but I looked it up and you're right. The developer isn't losing any of it's magnetic properties, it's losing charge because the the DV hasn't been stirred in a while. Correct me if I'm wrong.


However, calibration does much more than simply stir the developer so I'm unsure if a good stir is what's actually correcting the under toning problem.


PS - I buy machines from wholesalers and I assume they've been sitting in a warehouse for long periods of time without use and when I test them out, they don't have the undertone problem.

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

blackcat,

... When I said, lost "magnetic" property, I wasn't talking about losing it entirely...only becoming weaker. I never heard the term: triboelectric effect but I looked it up and you're right. The developer isn't losing any of it's magnetic properties, it's losing charge because the the DV hasn't been stirred in a while. Correct me if I'm wrong...

Correct. Tribo-electric effect only happens when stirred for a minimum amount of time, and quickly dissipates when not stirred.

... However, calibration does much more than simply stir the developer so I'm unsure if a good stir is what's actually correcting the under toning problem...

I'm sure calibration helps, but its the stirring that does the trick, however you have to get it to happen.

I started a thread not too long ago about a Konica Minolta PRESS C1060 that gave magenta developer high density errors two days after a developer change. It turned out that the enduser ran 30K black only prints and not a single color image. The cure comes from an unexpected quarter. In situations that the enduser runs high volumes of low density fill the primary transfer blade can wear prematurely for lack of lubrication. KM has a function to create an "exit toner band", that is, every 50 pages the machine puts down a 1.5% fill band of each color onto the belt to lubricate the primary transfer belt blade. A unexpected side effect of making this exit band, is that it must stir the color developers a little, every 50 pages. Just what I needed!

PRESS C1060 with errors

... PS - I buy machines from wholesalers and I assume they've been sitting in a warehouse for long periods of time without use and when I test them out, they don't have the undertone problem.

If I was a wholesaler and I knew anything about copiers, just prior to delivery I would plug in the machine and run a quick 50 pages to get the developer agitated. I don't know that's what they do ... but I would. =^..^=

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

Here would be my counter argument:


If a simple stir of the DV unit is correcting the problem, why does calibration need to be run? You could simply print 20 pages (or pick a number) and the DV would get a good stir and the problem would correct itself?

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

Yes it would work, but that would mean that the enduser would have to make a conscious effort to make a certain percentage of color images in-between the black ones. I can't imagine that happening. =^..^=

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

Yes it would work, but that would mean that the enduser would have to make a conscious effort to make a certain percentage of color images in-between the black ones. I can't imagine that happening. =^..^=

I see what you're saying, but have you ever tried to run some color copies to see if it actually clears up the under-toning problem? You have more experience than me with this problem. I'd really like to know if the problem is an idle color DV unit or is calibration compensating for some other problem.

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

I see what you're saying, but have you ever tried to run some color copies to see if it actually clears up the under-toning problem? You have more experience than me with this problem. I'd really like to know if the problem is an idle color DV unit or is calibration compensating for some other problem.

If you walk up to the machine and manually do ONLY a developer refresh, than make some prints (and the issue is resolved), then your developer refresh solved the issue.

If you do a color calibration, the machine automatically does a developer refresh, among other things.

Does it really matter how you get the desired effect? I guess I don't know where you're going with this. The purpose of color calibration is to continually compensate for variables like developer density, drum wear, transfer belt wear, charge roller wear, among other things. It's perfectly OK to compensate. That's what calibration is for. =^..^=

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

If you walk up to the machine and manually do ONLY a developer refresh, than make some prints (and the issue is resolved), then your developer refresh solved the issue.

If you do a color calibration, the machine automatically does a developer refresh, among other things.

Does it really matter how you get the desired effect? I guess I don't know where you're going with this. =^..^=

Here's where I'm going and I could be totally off-base. If the problem isn't a simple stir of the DV unit and we're making the machine run calibration more often than it's set from the factory, what effect is this having? Calibration can increase the DV bias, toner ratio and other things. Is it causing the machine to run dirtier? I don't know. It may not cause any undesired effects. Just thinking out loud.

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

Here's where I'm going and I could be totally off-base. If the problem isn't a simple stir of the DV unit and we're making the machine run calibration more often than it's set from the factory, what effect is this having? Calibration can increase the DV bias, toner ratio and other things. Is it causing the machine to run dirtier? I don't know. It may not cause any undesired effects. Just thinking out loud.

All those consumables will have to get changed eventually. I like that the machine has the ability to compensate for these variables. Otherwise we would be back in the analog days where every 20K images we'd be tweaking lamp intensity, developer bias, and primary charge to maintain image quality. It's pretty nice that the machine can do this all by itself. =^..^=

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

All those consumables will have to get changed eventually. I like that the machine has the ability to compensate for these variables. Otherwise we would be back in the analog days where every 20K images we'd be tweaking lamp intensity, developer bias, and primary charge to maintain image quality. It's pretty nice that the machine can do this all by itself. =^..^=

I suppose you're right. Sorry for being a pain in ass. I was more curious than anything.

[blackcat4866]

Re: Kyocera 3051ci white lines Dev units going bad?

I suppose you're right. Sorry for being a pain in ass. I was more curious than anything.

You're making my brain hurt. I don't usually get to think this much. LOL =^..^=

[tsbservice]

Re: Kyocera 3051ci white lines Dev units going bad?

If you walk up to the machine and manually do ONLY a developer refresh, than make some prints (and the issue is resolved), then your developer refresh solved the issue.

If you do a color calibration, the machine automatically does a developer refresh, among other things.

Does it really matter how you get the desired effect? I guess I don't know where you're going with this. The purpose of color calibration is to continually compensate for variables like developer density, drum wear, transfer belt wear, charge roller wear, among other things. It's perfectly OK to compensate. That's what calibration is for. =^..^=

Off topic I know.

We have some KM bizhub C224e doing a tons of BW printing and zero color output. And yes I know it's wrong model for this customer. The point is that, every time I check the machine - bird page coming great, solid halftones CMYK are great, no developer stirring here as you know machine has only basic calibrations and that's all. Brilliant engineering job they made with this model!

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

One last thing.


My problem machine has a different problem than the one blackcat describes and it's bugging me because I can't wrap my mind around the problem.

This customer prints color every day. And a lot of it. Yet, the colors looked washed out @ Magenta and Cyan. I can run DV refresh and calibration and it clears the problem right up. But it returns days later. The customer doesn't even realize the problem because all they print is "spot" color. But I know the problem is there.

I'm not gonna change the calibration rate on the customer's machine. I'm gonna change both DV units and bring the problem DV units back to the shop and install in my test machine. These DV units only have about 100k on them. If I find anything, I'll let everyone know.

[BillyCarpenter]

Re: Kyocera 3051ci white lines Dev units going bad?

You're making my brain hurt. I don't usually get to think this much. LOL =^..^=

You'll have to overlook me, I drive everyone crazy with a bunch of questions. Just ask slim and Ken. I must have asked them a million questions about networking. I don't mean anything by it. Just my way of learning and you've been a huge help. In fact, with everything I've learned from you about the color machines, I'm starting to feel like a real copier tech again.

[Samanator]

Re: Kyocera 3051ci white lines Dev units going bad?

In my technical life, I have always gone with the attitude that there are no stupid questions, just sometimes mean or wiseass answers. Or sometimes answers that unknowingly had the wrong facts.

For years I have fearlessly and without remorse asked what some others might think was a stupid or obvious question.

It has served me well as I have learned a lot.