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JDR
09-05-2018, 06:04 PM
Hi guys,
I encountered an issue with a KM C258 arround 100k (40k black)
Looks like an black eraser assembly issue but not sure (monochromy in cyan, magenta and yellow ok).
First half of the sheet, everything is fine but the second half has an offsetting issue.
Had tried a new black drum and transfer belt but still happening.
Any idea before i disassemble that innocent machine ? :D

Phil B.
09-05-2018, 09:04 PM
Hi guys,
I encountered an issue with a KM C258 arround 100k (40k black)
Looks like an black eraser assembly issue but not sure (monochromy in cyan, magenta and yellow ok).
First half of the sheet, everything is fine but the second half has an offsetting issue.
Had tried a new black drum and transfer belt but still happening.
Any idea before i disassemble that innocent machine ? :D

could be a LSU. Seen that on Ricoh and Color HPs

copier addict
09-05-2018, 09:52 PM
Have you tried using a thick paper setting? Even if it isn't thick paper the density of the toner could be causing the problem. Just a thought.

Synthohol
09-05-2018, 11:14 PM
does look like an erase lamp failure, but it may be fuser?
if fuser has the offset image there is this advice...
Error
Image is offset during fusing.

Root Cause
Firmware requires updating.

Workaround/Fix
Install special firmware GC2-E1 and set newly created Engine FW DipSW 13 by performing the following procedure.
1. Enter Service Mode
2. Utility/Stop/00/Stop/01
3. Enter Enhanced Security
4. Stop/0/Clear
5. Engine FW DipSw
6. Highlight Engine FW DipSw 13
7. Back out of Service Mode and Turn OFFMain Power Switch

blackcat4866
09-06-2018, 02:37 AM
96mm interval is most certainly a drum. The laser is responsible for drum cleaning and imaging, so if you have one you must necessarily have the other. But there might be a drum grounding or drum memory issue. Almost certainly the black drum will solve your issue. =^..^=

tsbservice
09-06-2018, 09:53 AM
In fact topic starter said he replaced black drum. As fusing pressure roller and drums have same pitch interval of 94mm, i would stay with Synthohol on this one.

JDR
09-06-2018, 11:27 AM
thanks guys for all your replies.
I have already replaced drum and transfer belt and tried with another fuser (just in case).
I though about erase led but LSU seems to be a good idea.
I gonna try this out.

JDR
09-13-2018, 04:17 PM
Here what i can report to you :
I have tried to replace erase LED, LSU, ITB, Black drum, black developper, fuser, FRB... and the issue still occurs.
Even tried a self check diag where everything is OK (except 2nd dimm error).
Dunno what to do realy except a data clear...

Synthohol
09-13-2018, 07:40 PM
Not for nothing, I have seen issues like this when the file has layers and is not flattened properly and the underlying image still shows up.
Does it do it with every job or just this one?
Print the built in demo page a few times. Lots of black there and let's see if it repeats like your attachment.

darry1322
09-13-2018, 08:04 PM
The odd thing to me is that it appears that the white lettering (paper surface) is what is being shadowed with toner later on the page. It's not like it's a toner repeat. It's more of a negative shadow. I can't figure a good explanation for this one.

copier addict
09-14-2018, 12:31 AM
The odd thing to me is that it appears that the white lettering (paper surface) is what is being shadowed with toner later on the page. It's not like it's a toner repeat. It's more of a negative shadow. I can't figure a good explanation for this one.

Have you stopped during print cycle to see the same image is on the transfer belt?

JDR
09-14-2018, 08:46 AM
Well that issue occures only with high coverage prints.
If i print the bird demo, the work is perfect.

After a print, i removed the belt to check : the issue was on the sheet but not visible on the belt.

And i'm agree with darry, looks like negative shadows...

Toxic
09-14-2018, 09:30 AM
When you replaced ITB did you replace transfer roller,just guess...

Gift
09-14-2018, 09:41 AM
This ghosting image looks like the charge or grounding isn't evenly spreaded among the surface after the erasing so the OPC surface isn't properly prepared for processing, that's why you noticed ghosting from frevious drum rotation with hard contrast image parts. Perhaps you can try and improve the drum grounding with conductive grease and you also might test the same file on a different C258 / xx8 to see if this might be (more or less) reproduceable there as well. You might also try and swap or re-seat the HV board or try some sp mode fiddling first (I'm not so familiar wih KM but there's probably some charge related settings you can mess around with^^).

Don N.
09-14-2018, 02:26 PM
Any possibility of a power supply issue, as c220 series sometimes caused some fusing offset?

UKTeam
09-14-2018, 02:30 PM
Well its been a while since I posted here, but I still read most weekdays.

I want to jump in on this thread because I have had exactly this, although it was a C224e.
Don't ask me why, because the MFP was in a standard office, not too hot, not too cold, not too humid...etc.
And the issue as you say, shows on the fuller fills.

You are seeing the remnants of a latent Drum image which is not fully discharged.

I managed to cure this by reducing the PRIMARY transfer voltage. (Not secondary..!)

Service Mode - Image Process Adjust - Trans Voltage Fine Adj.
Start by setting all colours to minimum (-8) and gradually bring them back up a step at a time until the image issue re-occurs.
Then simply drop back one step until you are happy.
I believe mine was a mix of -4 and -5.

It will be interesting to know if this helps you, particularly since this is a C258 Direct contact Charge Drum Unit as opposed to the C224e Air charging...

regards,
Mark

JDR
09-18-2018, 09:09 AM
Well its been a while since I posted here, but I still read most weekdays.

I want to jump in on this thread because I have had exactly this, although it was a C224e.
Don't ask me why, because the MFP was in a standard office, not too hot, not too cold, not too humid...etc.
And the issue as you say, shows on the fuller fills.

You are seeing the remnants of a latent Drum image which is not fully discharged.

I managed to cure this by reducing the PRIMARY transfer voltage. (Not secondary..!)

Service Mode - Image Process Adjust - Trans Voltage Fine Adj.
Start by setting all colours to minimum (-8) and gradually bring them back up a step at a time until the image issue re-occurs.
Then simply drop back one step until you are happy.
I believe mine was a mix of -4 and -5.

It will be interesting to know if this helps you, particularly since this is a C258 Direct contact Charge Drum Unit as opposed to the C224e Air charging...

regards,
Mark

Looks like you got it !
I had to set all values to -6 to fix this issue.
Does it mean HV board is faulty ?

UKTeam
09-24-2018, 02:59 PM
Sorry JDR, had a week off work and missed this...

Firstly, I'm glad this works for you too, and thanks for the feedback.

As for the question "Is the HV PCB faulty", no I don't think so.
Its just some undefined environment issue.
My 224e is just as happy now as it was a couple of years ago when I changed these settings.
Don't worry anymore about it..!

Mark

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