Bizhub C350 - foggy strip on color prints

[com_flyer]

Hi everyone,

I have an old Konica-Minolta Bizhub C350, which is perfectly working with one exception: a foggy strip running from top to bottom appears on the trailing edge of every color copy or print (see attachment). It does not appear on black copies or prints. The width of the strip varies from time to time with no appearent reason. It has always the same black/magenta/brown color, not depending of the printed color.

Fuser and transfer belt do have about 27000 copies, imaging units and 2nd transfer roller less than 10000.

Could someone tell me please, where it does come from and what to do? This problem is not described in the service manual ...

Kind regards

Pierre20201226_140639.jpg

[copier tech]

Re: Bizhub C350 - foggy strip on color prints

Hi everyone,

I have an old Konica-Minolta Bizhub C350, which is perfectly working with one exception: a foggy strip running from top to bottom appears on the trailing edge of every color copy or print (see attachment). It does not appear on black copies or prints. The width of the strip varies from time to time with no appearent reason. It has always the same black/magenta/brown color, not depending of the printed color.

Fuser and transfer belt do have about 27000 copies, imaging units and 2nd transfer roller less than 10000.

Could someone tell me please, where it does come from and what to do? This problem is not described in the service manual ...

Kind regards

Pierre[ATTACH=CONFIG]48070[/ATTACH]

This is such an old model could be caused by a number of units.

However since this happens on multiple colours & from looking at your print sample I'd say your issue us caused by the transfer unit.

You can remove strip & clean this part but if is preferable to fit a new one.

[com_flyer]

Re: Bizhub C350 - foggy strip on color prints

Hi,

Thanks for your quick reply.

I can't figure out where the color printing process differs from the black printing process, making the strip to appear only in the first case. The transfer process is exactly the same when printing monochrome or color. How could it be the transfer unit then?

I know, it's an old machine, but it has only 450'000 prints and its construction is much more solid than thmany newer machines. And, tell me, where can you find a fusing unit for USD 27 and imaging units for USD 50 for recent MFPs? This machine costs me virtually nothing.

Kind regards

[BillyCarpenter]

Re: Bizhub C350 - foggy strip on color prints

Hi,

Thanks for your quick reply.

I can't figure out where the color printing process differs from the black printing process, making the strip to appear only in the first case. The transfer process is exactly the same when printing monochrome or color. How could it be the transfer unit then?

I know, it's an old machine, but it has only 450'000 prints and its construction is much more solid than thmany newer machines. And, tell me, where can you find a fusing unit for USD 27 and imaging units for USD 50 for recent MFPs? This machine costs me virtually nothing.

Kind regards

When the same problem appears on multiple colors, that's big indication that the problem lies with the transfer unit. I'm a little confused from your test print. You say no problem occurs on black but you only posted a black test print? And I'm not exactly sure of what I'm looking at. Not sure of the paper direction. Always a good idea to draw an arrow that indicates paper direction.

PS - Post test prints for all colors, please.

[tsbservice]

Re: Bizhub C350 - foggy strip on color prints

Billy please re-read. From author description it is clear what problem he experience. Foggy band on trailing edge perpendicular to feeding direction. No band in black only print though.

[BillyCarpenter]

Re: Bizhub C350 - foggy strip on color prints

Billy please re-read. From author description it is clear what problem he experience. Foggy band on trailing edge perpendicular to feeding direction. No band in black only print though.

I read it about 4 times and I'm still not clear.

He says:



"top to bottom appears on the trailing edge of every color copy or print."


How can the band run from top to bottom but only @ trailing edge? Maybe I'm just reading it wrong. I dunno. And why not post all the colors? He says the problem only appears on color. Maybe I didn't get enough sleep.

[com_flyer]

Re: Bizhub C350 - foggy strip on color prints

Sorry if I'm not clear (english is not my mothertongue) ...

The shown picture is a "zoom in" detail of a color A4 portrait test-print which includes a black part; it does not show the entire page. Paper direction is from right (leading edge not shown) to left (trailing edge shown on picture). The foggy strip is shown on the left, near the trailing edge of the paper.

As said:
- the strip appears on color copies ONLY. Black only copies are just perfect.
- the strip has always the same black-brown-magenta color, regardless of what color is printed. It has this color even on a yellow only test-page.
- the strip runs from top to bottom of the paper. It has a width of about 4-6 mm and is located about 3-4 mm away from the trailing edge of the paper.

Hard to believe that the transfer unit could be faulty, when black prints are perfect and only color printouts are affected, isn't it?

The shitty color of the strip looks more or less like waste toner. But if it is waste toner, how can it get there and only on color copies?

[BillyCarpenter]

Re: Bizhub C350 - foggy strip on color prints

Sorry if I'm not clear (english is not my mothertongue) ...

The shown picture is a "zoom in" detail of a color A4 portrait test-print which includes a black part; it does not show the entire page. Paper direction is from right (leading edge not shown) to left (trailing edge shown on picture). The foggy strip is shown on the left, near the trailing edge of the paper.

As said:
- the strip appears on color copies ONLY. Black only copies are just perfect.
- the strip has always the same black-brown-magenta color, regardless of what color is printed. It has this color even on a yellow only test-page.
- the strip runs from top to bottom of the paper. It has a width of about 4-6 mm and is located about 3-4 mm away from the trailing edge of the paper.

Hard to believe that the transfer unit could be faulty, when black prints are perfect and only color printouts are affected, isn't it?

The shitty color of the strip looks more or less like waste toner. But if it is waste toner, how can it get there and only on color copies?

Everyone but me seemed to have understood what you were saying so the misunderstanding would lie with me it appears.


Try cleaning the transfer belt as copier tech suggested. It may have trash accumulated somewhere.

[allan]

Re: Bizhub C350 - foggy strip on color prints

Please post some half-tones at 125 of 255.
That should give a better idea of the quality of the colors.

[com_flyer]

Re: Bizhub C350 - foggy strip on color prints

Well, it's not as easy as that to make the foggy strip visible on a scanned copy. I did my best and you can find a magenta testprint in appendix.

The picture shows the paper direction and the strip on the left. On the picture, it look as if the strip was magenta also, but it is not. Its color is black-brown.

[tsbservice]

Re: Bizhub C350 - foggy strip on color prints

Well, it's not as easy as that to make the foggy strip visible on a scanned copy. I did my best and you can find a magenta testprint in appendix.

The picture shows the paper direction and the strip on the left. On the picture, it look as if the strip was magenta also, but it is not. Its color is black-brown.

Hmm, that is not trail edge but Lead!

[com_flyer]

Re: Bizhub C350 - foggy strip on color prints

The drawn arrow shows the way the paper is printed : tail of arrow comes out first, tip of arrow comes out last. The dirty strip is definitely on the trailing edge.

I now tried what I generally hate to do: play with the image settings. And to slow down the second transfer roller did help. So it seems to be a syncronising problem between the speed of the transfer belt and the 2nd transfer roller. Let's see of it holds ... I will keep you updated.

Have a nice weekend