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bobdee
12-13-2021, 11:28 PM
I am using Konica Minolta Bizhub C45. The Machine works correctly until recently the yellow keep repeat image. I have tried the Transfer Belt in other machine and it works fine. When I swapped Yellow and Cyan Drum Units, the yellow Image still keep repeating itself whiles the Yellow Drum Unit Prints correctly at the Cyan Slot.

Attached is a copy of an envelope printed by the printer.

copier addict
12-13-2021, 11:44 PM
I am using Konica Minolta Bizhub C45. The Machine works correctly until recently the yellow keep repeat image. I have tried the Transfer Belt in other machine and it works fine. When I swapped Yellow and Cyan Drum Units, the yellow Image still keep repeating itself whiles the Yellow Drum Unit Prints correctly at the Cyan Slot.

Attached is a copy of an envelope printed by the printer.


How often does the fault repeat? Is it always the same shape?

adecanmin
12-13-2021, 11:45 PM
I am using Konica Minolta Bizhub C45. The Machine works correctly until recently the yellow keep repeat image. I have tried the Transfer Belt in other machine and it works fine. When I swapped Yellow and Cyan Drum Units, the yellow Image still keep repeating itself whiles the Yellow Drum Unit Prints correctly at the Cyan Slot.

Attached is a copy of an envelope printed by the printer.

OEM toner? You can up the heat in the fuser Thick 1?

bobdee
12-13-2021, 11:57 PM
How often does the fault repeat? Is it always the same shape?

Mostly the same shape and there is bit spread of yellow after the yellow image is repeated. You can check the image attached

bobdee
12-14-2021, 12:00 AM
OEM toner? You can up the heat in the fuser Thick 1?

Please this happens to only Yellow. When you swapped the yellow drum unit to either Magenta or Cyan, it prints correct without repeating image. But when you place any drum Unit at the yellow slot, it repeats the image even new drum unit.

blackcat4866
12-14-2021, 12:42 AM
If the yellow developer is overtoning you can see something like this.

Phil B.
12-14-2021, 12:46 AM
I am using Konica Minolta Bizhub C45. The Machine works correctly until recently the yellow keep repeat image. I have tried the Transfer Belt in other machine and it works fine. When I swapped Yellow and Cyan Drum Units, the yellow Image still keep repeating itself whiles the Yellow Drum Unit Prints correctly at the Cyan Slot.

Attached is a copy of an envelope printed by the printer.Ok.. missing something.
When you swap Y to C..it still has the defect on the c now Y drum?
So.. problem didn't move, what is the other part in image formation chain?
HINT yellow dev unit.
It did move with drum swap.. Drum


Sent from my SM-G960U using Tapatalk

Toxic
12-14-2021, 01:24 AM
I think erase lamp for yellow does not work.
Have that case on other machine series, unpluged connector for led erase lamp.

Woxner
12-14-2021, 02:53 AM
Does this happen on other color copies?

femaster
12-14-2021, 05:01 AM
Definitely check yellow development unit as others have suggested, but I was thinking along the same lines as Toxic, that there might by an issue with the yellow erase lamps.

TEST10
12-14-2021, 06:32 AM
Please this happens to only Yellow. When you swapped the yellow drum unit to either Magenta or Cyan, it prints correct without repeating image. But when you place any drum Unit at the yellow slot, it repeats the image even new drum unit.

When you say that you try other drum units on the yellow and you get the same problem of the repatted image, the yellow development unit remains? have you only tried cylinder unit?
Because I remember something similar once and it was moisture in the toner!

bobdee
12-14-2021, 07:41 AM
If the yellow developer is overtoning you can see something like this.

Please Thanks for your concern. If I may ask, what causes the developer to overtone??

bobdee
12-14-2021, 07:50 AM
When you say that you try other drum units on the yellow and you get the same problem of the repatted image, the yellow development unit remains? have you only tried cylinder unit?
Because I remember something similar once and it was moisture in the toner!

Please thanks for your support. Yes, I changed only the Yellow Drum Unit, whiles the Developer Unit remains in the machine. I have never tried changing the Developer Unit.

bobdee
12-14-2021, 08:13 AM
Ok.. missing something.
When you swap Y to C..it still has the defect on the c now Y drum?
So.. problem didn't move, what is the other part in image formation chain?
HINT yellow dev unit.
It did move with drum swap.. Drum


Sent from my SM-G960U using Tapatalk

Thanks. Yes, When I swapped C to Y, still the image repeated at yellow whiles printing with C drum there. Apart from the yellow repeats image, the printer prints fine.

bobdee
12-14-2021, 08:17 AM
I think erase lamp for yellow does not work.
Have that case on other machine series, unpluged connector for led erase lamp.

Thank you, I will try that.

bobdee
12-14-2021, 08:20 AM
Does this happen on other color copies?

Thanks. Yes, it does to colour Text and images and it's only Yellow that causes that

bobdee
12-14-2021, 08:23 AM
Definitely check yellow development unit as others have suggested, but I was thinking along the same lines as Toxic, that there might by an issue with the yellow erase lamps.

Ok, I will check both developer unit and the erase lamp of the Yellow.

tsbservice
12-14-2021, 01:20 PM
Please Thanks for your concern. If I may ask, what causes the developer to overtone??
Old developer material and compatible toner(I suppose without added developer in it).
As for erase leds(lamp) you can trick the machine with front door open and WTB removed and whatch for it.

bobdee
12-14-2021, 07:00 PM
Old developer material and compatible toner(I suppose without added developer in it).
As for erase leds(lamp) you can trick the machine with front door open and WTB removed and whatch for it.

Thanks, I i will check and see

romario
12-18-2021, 02:50 AM
I am using Konica Minolta Bizhub C45. The Machine works correctly until recently the yellow keep repeat image. I have tried the Transfer Belt in other machine and it works fine. When I swapped Yellow and Cyan Drum Units, the yellow Image still keep repeating itself whiles the Yellow Drum Unit Prints correctly at the Cyan Slot.

Attached is a copy of an envelope printed by the printer.


if you change the drum unit Y to the C and the fault remains in the Y. Just change the development unit Y. or developer And that has to solve your problem

blackcat4866
12-18-2021, 02:27 PM
... If I may ask, what causes the developer to overtone??

That's a great question. And there are a lot of answers:

1) Underuse: If you're running 95% monochrome/5% color, the color developers are just sitting there unstirred for long periods of time. The toner settles out of the developer mix. When you do decide to make a color print, it takes a while to get the developer particles charged back up and all the toner stirred back in. During that process, the machine is adding more toner.

2) Generic toner: Electrically, generic toner does not always respond exactly the same as genuine toner. So when the correct amount of generic toner is mixed into the developer, it doesn't always respond to the toner sensor the same way, so it just keeps adding toner to try to get the toner sensor up to 6%.

3) Contamination: Basically the same effect as generic toner. Endusers that use a very poor quality of paper (very high dust content), or in an environment that has a very high level of airborne contamination (like a grindstone manufacturing plant or an iron foundry), that airborne contamination ends up in the developing unit. And if that contamination has magnetic or electrical properties it changes the way the toner sensor reads. Paper dust does not have magnetic or electrical properties, but displaces toner, and leaves light areas (paper dust won't make up a visible latent image).

4) Developer is worn out: When the manufacturer calculates the developer yield it's based on ~4% image fill of each color, and so many color pages. If your color pages are, say 20%, you'll make 1/5th the number of pages. You probably do not know the exact image fill of every color page that you've printed.

In the end though this is all just interesting conversation. Knowing it does not change the need to order a yellow developing unit. =^..^=

BillyCarpenter
12-18-2021, 02:52 PM
That's a great question. And there are a lot of answers:

1) Underuse: If you're running 95% monochrome/5% color, the color developers are just sitting there unstirred for long periods of time. The toner settles out of the developer mix. When you do decide to make a color print, it takes a while to get the developer particles charged back up and all the toner stirred back in. During that process, the machine is adding more toner.

2) Generic toner: Electrically, generic toner does not always respond exactly the same as genuine toner. So when the correct amount of generic toner is mixed into the developer, it doesn't always respond to the toner sensor the same way, so it just keeps adding toner to try to get the toner sensor up to 6%.

3) Contamination: Basically the same effect as generic toner. Endusers that use a very poor quality of paper (very high dust content), or in an environment that has a very high level of airborne contamination (like a grindstone manufacturing plant or an iron foundry), that airborne contamination ends up in the developing unit. And if that contamination has magnetic or electrical properties it changes the way the toner sensor reads. Paper dust does not have magnetic or electrical properties, but displaces toner, and leaves light areas (paper dust won't make up a visible latent image).

4) Developer is worn out: When the manufacturer calculates the developer yield it's based on ~4% image fill of each color, and so many color pages. If your color pages are, say 20%, you'll make 1/5th the number of pages. You probably do not know the exact image fill of every color page that you've printed.

In the end though this is all just interesting conversation. Knowing it does not change the need to order a yellow developing unit. =^..^=


That's a very detailed explanation. I enjoyed reading it.

JasonSBE
02-26-2023, 10:56 PM
I had a very similar issue on a C658 recently. I diagnosed it by swapping drums first, then testing the developer, then swapping the erasure lamp between the color affected(in my case cyan) and another color. None of those things took care of it, so I replaced the FRB board. Apparently the connector wasn't powering the erasure lamp for cyan because that fixed it.

edit:

Just realized that this was a thread from a couple years ago. I'll leave my reply in case it's helpful for someone down the road.

Hansoon
02-26-2023, 11:34 PM
And I just had it these days. Also with yellow. Resetting the yellow DevUnit cured it for the moment until I make a fresh unit next week.

Reread Cat's explanation and am impressed once again....., as always......

Hans

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