[CQ] bizub C284 - Developing unit Cyan malfunction?

[Laserbeam]

Hi,

the Cyan Colour (Halftone) shows a funny pattern. I renewed the developing unit cyan and all was fine.
After 4 weeks the same problem occured (see the attachment).
TCR-C value is 6,9%
What else could cause this error?

[Albonline]

Re: bizub C284 - Developing unit Cyan malfunction?

there are bulletins about hv shorts/leaks on this series, but most often this type of problem with cyan turns out to be related to the black image system being worn out, past life, and overdriving everything to make a decent image.

[copier tech]

Re: bizub C284 - Developing unit Cyan malfunction?

Hi,

the Cyan Colour (Halftone) shows a funny pattern. I renewed the developing unit cyan and all was fine.
After 4 weeks the same problem occured (see the attachment).
TCR-C value is 6,9%
What else could cause this error?

Failure of Image Unit or Developer Unit.pdf

While you are troubleshooting this issue you can use the old dev from a failed unit to save keep replacing a new one each time.

[Ashbell]

Re: bizub C284 - Developing unit Cyan malfunction?

Had an issue like this a while ago. Ours was on black though, it was caused by a stripped Dev, unsure if it is the same but the patterns look exactly the same. Unfortunately i dont have my sample pages any more or i would show them.

[Copier & Repair LLC]

Re: bizub C284 - Developing unit Cyan malfunction?

probably there is leaking in the developing unit, try to weight the developer and then add some from the replaced one if it missing some
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[Don N.]

Re: bizub C284 - Developing unit Cyan malfunction?

[ATTACH]38162[/ATTACH]

While you are troubleshooting this issue you can use the old dev from a failed unit to save keep replacing a new one each time.

How do you determine the right qty or level of dev to replenish? We've had several in the c220 series do this. I agree it's the HV/drum charge/rechipped drums mainly causing it and we've saved several dv units to top off the dev. Do you just fill until you get total mag roller coverage? If I had an extremely accurate scale, I would weigh a new dev unit.
Curious... Thanks

[allan]

Re: bizub C284 - Developing unit Cyan malfunction?

How do you determine the right qty or level of dev to replenish? We've had several in the c220 series do this. I agree it's the HV/drum charge/rechipped drums mainly causing it and we've saved several dv units to top off the dev. Do you just fill until you get total mag roller coverage? If I had an extremely accurate scale, I would weigh a new dev unit.
Curious... Thanks

There is a top port for excess developer to be discarded to the waste box so if you overfill it a little the extra dev will drop into the waste box, just don't fill it to where the gears wont turn freely.

[copier tech]

Re: bizub C284 - Developing unit Cyan malfunction?

There is a top port for excess developer to be discarded to the waste box so if you overfill it a little the extra dev will drop into the waste box, just don't fill it to where the gears wont turn freely.

[Hansoon]

Re: bizub C284 - Developing unit Cyan malfunction?

weighing say a magenta unit & topping up ur cyan until the same weight is a very good idea!

We have a fine scale in our workshop dedicated for that purpose and even do I carry a scale always in my car to test remaining amount of toner still left in machines when I go to our wholesaler to pick up machines. Easy to save a lot of money when sorting out toner bottles/cartridges.

Hans

[AjitN]

Re: bizub C284 - Developing unit Cyan malfunction?

There is a top port for excess developer to be discarded to the waste box so if you overfill it a little the extra dev will drop into the waste box, just don't fill it to where the gears wont turn freely.

When you turn mag roll in opposite direction the developer will not be seen for first turn, but in next turns it should be all over magnetic roll may be in same pattern what you have shown in sample BUT IT SHOULD BE ALL OVER MAGNETIC ROLL FROM BACK SIDE OF MACHINE( INBOARD TO OUT BOARD). We have done this in many cases without checking weight of developer, it's not needed. I am doing this since C252 Model.
I would request you to check on this forum for failure of cyan developer and toner.
Most of the time it is toner which is although looks like OEM but it is not.
Hope this helps
Ajit

[Laserbeam]

Re: bizub C284 - Developing unit Cyan malfunction?

Thank you very much for your contributions!

@ copier tech
I compared the values with those of this service bulletin. All values are in the normal range. All 4 drum-units were renewed in March and still have about 60% of life expectancy. The tranfer belt is overlife about 50K.

Today this problem occured again !!!!!!!!! Developer deficiency in the cyan unit. After about only 2000 copies / printouts. The display shows failure P-21, P-6, P-28 This time I renewed the transfer belt / roller, cleaned the 2 IDC sensors, run Stabilizer (Initialize + Image Stabilization) and performed Gradation Adjustment.

I think, that this issue is a result of a HV board failure and not a problem of overlife drum/developer/transfer belt units. I'm ordering a new one now.

[REGSIS]

Re: bizub C284 - Developing unit Cyan malfunction?

All 4 drum-units were renewed in March.......
This time I renewed the transfer belt / roller

I think, that this issue is a result of a HV board failure and not a problem of overlife drum/developer/transfer belt units. I'm ordering a new one now.

What do you mean by renewed? You put new OEM drum unit and ITB, or you put new compatible parts in old drum units???

You must be aware that drum itself (cylinder) is not the root cause of the developer depletion. In my experience it's the charge unit which is housed in drum unit (you can see black area on scorotron grid usually on front side)

In case of failure sparks appear on that spot and charge drum abnormally and that charge attracts developer and depletes it from developing unit.

In most cases leakage is just outside paper area and cannot be noticed until it's too late.

[Laserbeam]

Re: bizub C284 - Developing unit Cyan malfunction?

Yes, we only use original consumables from Konicaminolta, but you are right, REGSIS, I noticed the same thing when I looked closely at the scorotron grid of the cyan drum. The rear and the front side are contaminated with toner. After that I renewed this unit, but forgot to mention it in my last post. Sorry!

[REGSIS]

Re: bizub C284 - Developing unit Cyan malfunction?

We're not talking about same thing, you've got contamination at that point because developer is depleted at that point.
I'm talikng about some kind of "burning". Check black drum unit for burning. Cyan issue is mostly caused by black drum overlife. Is your transfer belt matted at that point? Someone smoking near the machine?

If I got you correctly with all 4 new OEM drum units and new transfer belt the issue is back?


P.S. Your feedback helps others to solve similar problem.

[copier tech]

Re: bizub C284 - Developing unit Cyan malfunction?

Thank you very much for your contributions!

@ copier tech
I compared the values with those of this service bulletin. All values are in the normal range. All 4 drum-units were renewed in March and still have about 60% of life expectancy. The tranfer belt is overlife about 50K.

Today this problem occured again !!!!!!!!! Developer deficiency in the cyan unit. After about only 2000 copies / printouts. The display shows failure P-21, P-6, P-28 This time I renewed the transfer belt / roller, cleaned the 2 IDC sensors, run Stabilizer (Initialize + Image Stabilization) and performed Gradation Adjustment.

I think, that this issue is a result of a HV board failure and not a problem of overlife drum/developer/transfer belt units. I'm ordering a new one now.