KM C6500 Problem with Black Shades and Gradation

[ITHPP]

Hi folks....
I am a newbie and not a tech...but a very determined end user. I am looking for a wise sage of a copy technician to lead me in the way.

I have a KM Bizhub Pro C6500 with almost 7 mil clicks. I have been doing all my own tech work. I run a small monthly community newsletter. I usually can make things work but I am stuck with my current issue. A few weeks ago my Black had problems with shading and gradations. The Black lays down an image that is dark, pixelated, with no shading, gradation or flow.
I did a full PM a few months ago and everything was going fine. After this issue started with the black, I replaced black drum, corona, developer, TCR sensor, and even tried swapping out the black laser write unit with one I know to be working but it still does not fix the issue. I have cleaned the PGC sensor, done auto gamma adjustments and just about everything else I know. I assume it is something in my settings. I just can't figure it out. I occasionally get a c-2804 code and I can clear that by going into I/O check mode and bringing the 54-09 parameter down to 135.
But no matter what I do, the black still looks the same. If I go to Quality Adj. and change any parameters on black it still looks the same.46659
Any thoughts or ways to search out this issue?

I am so thankful for the incredible folks in this forum. It has been so so helpful on many issues.

I am attaching a few pictures to show the issue. I have on there the original file, a photo of the file printed on an HP M880 and a photo of the problematic black on the KM C6500.

Thank you!!!

[Toxic]

I would try this

"Service Mode Menu screen"
Press [01 Machine Adjustment].
2. "Machine Adjustment Menu screen"
Press [01 Printer Adjustment].
3. "Printer Adjustment Menu screen"
Press [14 Recall Standard Data].
4. "Recall Standard Data screen"
Press [Installation Initial Data].

[ITHPP]

I would try this

"Service Mode Menu screen"
Press [01 Machine Adjustment].
2. "Machine Adjustment Menu screen"
Press [01 Printer Adjustment].
3. "Printer Adjustment Menu screen"
Press [14 Recall Standard Data].
4. "Recall Standard Data screen"
Press [Installation Initial Data].


Thank you for the input.
Tried it but it it did not change anything. Blacks still look just the same. Does anyone know if perhaps bad toner would do that? I have been getting what is said to be Genuine Konica Toner.

[BillyCarpenter]

Thank you for the input.
Tried it but it it did not change anything. Blacks still look just the same. Does anyone know if perhaps bad toner would do that? I have been getting what is said to be Genuine Konica Toner.

Bad toner can cause all kinds of problems. If you suspect bad toner, clean the old toner out and install a known good toner.

[Phil B.]

Hi folks....
I am a newbie and not a tech...but a very determined end user. I am looking for a wise sage of a copy technician to lead me in the way.

I have a KM Bizhub Pro C6500 with almost 7 mil clicks. I have been doing all my own tech work. I run a small monthly community newsletter. I usually can make things work but I am stuck with my current issue. A few weeks ago my Black had problems with shading and gradations. The Black lays down an image that is dark, pixelated, with no shading, gradation or flow.
I did a full PM a few months ago and everything was going fine. After this issue started with the black, I replaced black drum, corona, developer, TCR sensor, and even tried swapping out the black laser write unit with one I know to be working but it still does not fix the issue. I have cleaned the PGC sensor, done auto gamma adjustments and just about everything else I know. I assume it is something in my settings. I just can't figure it out. I occasionally get a c-2804 code and I can clear that by going into I/O check mode and bringing the 54-09 parameter down to 135.
But no matter what I do, the black still looks the same. If I go to Quality Adj. and change any parameters on black it still looks the same.46659
Any thoughts or ways to search out this issue?

I am so thankful for the incredible folks in this forum. It has been so so helpful on many issues.

I am attaching a few pictures to show the issue. I have on there the original file, a photo of the file printed on an HP M880 and a photo of the problematic black on the KM C6500.

Thank you!!!


when you 'replaced' dev unit did you INIT the new/used unit in SM?

are you using genuine OEM KM toner or are you using crap 3rd party toner?

have you seen this video? how to change developer in konica minolta C 6000 7000 | how to change developers in konica minolta - YouTube (https://youtu.be/5g3O5vgX0Ac)

does the mag roller have a thick complete 'brush' on it?

Phil B. ' The Dentist '

[Toxic]

What controller you have with this machine?
Post some color photo sample

[telip]

It seems to me like something is going on with your controller.You can try and do a color calibration,see how that goes.I am guessing that's a Creo..

[ITHPP]

It seems to me like something is going on with your controller.You can try and do a color calibration,see how that goes.I am guessing that's a Creo..


Thanks to all for your responses.
My server is a Fiery. I have tried doing color calibration. Didn't work. I did not replace the whole developer unit, only refresh of the developer powder. But it does look like there is an even mag roller "brush" line on the developer.

I have been buying toner off ebay that says it is Genuine Konica Toner, coming in Konica boxes but perhaps I got some low grade refill. I have not tried to replace all the toner yet. How can I get the toner out of the machine? Obviously pull out the toner bottle but then how can I clear out the hopper and what is in the machine?

Again...all the input is very very much appreciated!

[ITHPP]

Hello all who are following this thread.... It does seem like bad toner was the issue! I cleared out the toner hopper and replaced the toner bottle, ran a small run of sacrificial flyers to clear out the remaining old toner.... and it seems like the new toner bottle did the trick. I am very grateful for all the responses.... By the end of this machines life, I might just be a tech too!