Konica c70hc - wrong color

[Love Konica]

Hi all,

Customer 's machine prints with yellow color on every print sheets, please see the upload image. I have changed drum and corona but nothing changes.
c70hc-1.jpg
when I print test page, every thing is ok
c70hc.jpg

Please help me, thank you.

[methogod]

Re: Konica c70hc - wrong color

looks like your printing black and white in color...

make sure rich black is not turned on in the advanced setting.

IF you have rich black on in a grey scale photo you may get some fine registration marks off base....

also Konica use yellow for color registration.

are you printing from a computer, or right from the rip using a pdf workflow???

[Love Konica]

Re: Konica c70hc - wrong color

Thank methogod, my file is not B&W, yellow approximate 15-20%, even when I print color file the yellow still appears.

I print directly from a computer (to rip), not using workflow.

Thank you.

[Love Konica]

Re: Konica c70hc - wrong color

Any more ideas, help me please. Thanks in advance.

[KM1Amsterdam]

Re: Konica c70hc - wrong color

Toner from the developing cylinder is actually touching the Y drum. Increase the space between the drum and developing unit. Decrease the size of the developing brush, adjust the skimming blades gap.

[KM1Amsterdam]

Re: Konica c70hc - wrong color

U could try to increase the gap, by putting some tape around the 2 wheels left en right of the developer roll. It pushes the drum a tenth of a mm away.

[Love Konica]

Re: Konica c70hc - wrong color

U could try to increase the gap, by putting some tape around the 2 wheels left en right of the developer roll. It pushes the drum a tenth of a mm away.

Thank you, I have tried your way. It take a good results. Thanks all, especially KM1Amsterdam.
Hope everyone who has this case can read this thread.