KM C258 offsetting issue

[JDR]

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 ?

[Phil B.]

Re: KM C258 offsetting issue

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 ?

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

[Copier Addict]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

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]

Re: KM C258 offsetting issue

When you replaced ITB did you replace transfer roller,just guess...

[Gift]

Re: KM C258 offsetting issue

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.]

Re: KM C258 offsetting issue

Any possibility of a power supply issue, as c220 series sometimes caused some fusing offset?