Help. Konica Minolta Bizhub C759 double/ghost prints on 11x17 only.

[RUSORIZO]

Hello Everyone,

We have a Konica Minolta Bizhub C759 and having a problems with the print outs, with red/magenta shadows double/ghost prints. The problems only appears when we print on a 11x17" size paper but for a 8x11" the prints are good. You can print one at a time and they will all look good. But print like 10 or more and the first few will look good and then the rest will start to double/ghost. Please see below for sample prints:

45343 45342


The KM Bizhub C759: 2 years old
Total Counter: 86,730
The fusing unit is new
the 3 imaging units and drum are new CMYK

Did perform the Image Stabilization Only, Image + Stabilization, Print Skew Reset, and Color Registration Adjust but to no avail.

I appreciate the help.

[copyman]

Hello Everyone,

We have a Konica Minolta Bizhub C759 and having a problems with the print outs, with red/magenta shadows double/ghost prints. The problems only appears when we print on a 11x17" size paper but for a 8x11" the prints are good. You can print one at a time and they will all look good. But print like 10 or more and the first few will look good and then the rest will start to double/ghost. Please see below for sample prints:

45343 45342


The KM Bizhub C759: 2 years old
Total Counter: 86,730
The fusing unit is new
the 3 imaging units and drum are new CMYK

Did perform the Image Stabilization Only, Image + Stabilization, Print Skew Reset, and Color Registration Adjust but to no avail.

I appreciate the help.

Sorry don't know that model but with my Kon/Min experience just a few things come to mind.

When you are saying the IU's, Drum and fuser are new why would you have had to replace them with only 86K clicks? If it didn't have such a low meter I would say you had a bad magenat IU / drum. or possibly transfer belt! I've seen that on other Kon/Mins and it was dirty IDC sensors under trans belt. Usually with P codes.

You probably already have the attached from service manual but just in case.

[RUSORIZO]

Sorry don't know that model but with my Kon/Min experience just a few things come to mind.

When you are saying the IU's, Drum and fuser are new why would you have had to replace them with only 86K clicks? If it didn't have such a low meter I would say you had a bad magenat IU / drum. or possibly transfer belt! I've seen that on other Kon/Mins and it was dirty IDC sensors under trans belt. Usually with P codes.

You probably already have the attached from service manual but just in case.


Our techs replaced for a new IU's, Drum and fuser to check if the problem will be solve but still same problem occurred with no P codes showing. Our techs is having hard time to figure out the problem.

[tech51]

Our techs replaced for a new IU's, Drum and fuser to check if the problem will be solve but still same problem occurred with no P codes showing. Our techs is having hard time to figure out the problem.
I would definitely clean the idc sensors before doing any any other adjustments.

I have had a similar fault to this which only affected a3 size paper and adjusting the fuser speed cured it.

[occus]

Had this on a c552 long time ago. Skew reset twice and after a initialisation/stabilisation was a temp. solution. There was a tech bulletin to replace all IU's and the black drum also.

But check the IDC first. Its special that you doesn't have p codes.

[blackcat4866]

I can't remember where I've seen this before, but I have.

The color registration starts at the leading edge of the page correctly, but gets worse the longer the page runs. Notice that the yellow registration is the worst, magenta not quite as bad (but more visible because it's magenta), and cyan the least affected.

I suspect that you'll find some bind or drive failure in the primary transfer drive, slowing the belt slightly.
=^..^=

After checking the database, I've seen variations of color registration on the KM color presses because of worn 2nd transfer or worn registration roller.

[man in havana]

what thickness paper are you using and what are tray settings

have you tried cutting down paper to a4 size as it may be the stock

have you stopped copy process and looked at image on belt is that disformed

[tsbservice]

Check fusing loop sensors actuator springs and registration sensor springs. Reform or replace if necessary.

[man in havana]

on the old c552 c452 the sensor under the fuser plate snapped and caused same fault after about half the page as fuser went into a slower drive speed

[RUSORIZO]

I appreciate all of your advise. Our techs will try each every one of you guys suggestions. I will let you know the outcome.
Again, thank you so much for the help.

[Synaux]

what thickness paper are you using and what are tray settings

I have seen this happen on older series with thick paper only.

[RUSORIZO]

Does someone have a Konica Minolta Bizhub C759 Service Manual? Thank you.

[Oystercopy]

I don't think anyone mentioned this, but what kind of TONER are you using? OEM or Generic (like Katun garbage)? I know you're only seeing the problem on 11x17, but its possible its not showing up until the transfer belt has rotated longer... KMs rarely have image quality problems, especially with such a low mileage machine. And I'm with one of the other posts that asked why you replaced so many IUs if the machine only has 80K or so?
OC

[RUSORIZO]

I don't think anyone mentioned this, but what kind of TONER are you using? OEM or Generic (like Katun garbage)? I know you're only seeing the problem on 11x17, but its possible its not showing up until the transfer belt has rotated longer... KMs rarely have image quality problems, especially with such a low mileage machine. And I'm with one of the other posts that asked why you replaced so many IUs if the machine only has 80K or so?
OC


We are using OEM. Our Techs replaced the IUs to check if the problem will be fixed.
Yesterday, our Techs tried to install a new ITB but still same problem.

[Woxner]

go into service mode and see what the idc readings are. this just looks like color alignment problem. clean the sensors then do int. and reset then gradation.

[copiers01]

Hello Everyone,

We have a Konica Minolta Bizhub C759 and having a problems with the print outs, with red/magenta shadows double/ghost prints. The problems only appears when we print on a 11x17" size paper but for a 8x11" the prints are good. You can print one at a time and they will all look good. But print like 10 or more and the first few will look good and then the rest will start to double/ghost. Please see below for sample prints:

45343 45342


The KM Bizhub C759: 2 years old
Total Counter: 86,730
The fusing unit is new
the 3 imaging units and drum are new CMYK

Did perform the Image Stabilization Only, Image + Stabilization, Print Skew Reset, and Color Registration Adjust but to no avail.

I appreciate the help.

Hi,
I had a similar problem with the C458 e, I replaced the print head and the problem was solved.

[Seijinie]

Does anyone have any solution for this?
I replace almost all part of C759 machine but still confuse what is the reason for this.
MFP board, Transfer belt, idc, supply board...

[t85ster]

Are your guys trained/experienced on the Bizhubs?
1. Remove the Transfer Belt Unit and clean the two color registration sensors properly.
2. Make sure to use only OEM Toner!

[Phil B.]

Does someone have a Konica Minolta Bizhub C759 Service Manual? Thank you.

https://www.copytechnet.com/forums/service-manual-requests/ ALL manual requests are to be placed in that forum per forum rules.