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Black background with white haze around the text.

I have tryed replacing the main charge unit, transfer/sep unit, pre transfer unit and the drum. adjusted main charge bias up to max and down to min with no effect. please help me if you can.

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  • koma1971 Jan 16, 2009

    it is a canon imagrunner 7095. and it has close to 4 mil copies on it.

  • Mike May 11, 2010

    what model and make machine



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The prevailing thought at this time is that electrical noise caused by dust in the clutch, CL8, is the culprit.

As this investigation has progressed, a minor modification was made to a few sample DC Controllers to attempt to eliminate the electrical noise. Upon realization that the dust in the clutch is the cause, we no longer believe the resolution is a modified controller. Additionally, there were only a few of these controllers created to use in a few beta sights to evaluate the results. No more modified DC Controllers exist.

Although cleaning the clutch may resolve your immediate problem, we need sample paper feed assemblies to continue to investigate the cause. We would greatly appreciate anyone who can supply a paper feed assembly. Please call the TSC, and refer to me and / or this forum post and we will try to


Clutch was replaced first. No change,still black copies. Replaced unit and problem went away until now

Hopefully, this will help shed some more light on all of the trouble and speculation regarding this particular CQ issue.
The revision 120 DCC seems to have been taking care of the black copies with halo CQ issue.
The new and/or modified DCC is capable of filtering out the electrical noise that is caused by the stray metallic dust that accumulates inside some of the clutches.
Therefore the HVT circuit on the revision 120 DCC's should not be affected by this anymore.
Hope this helps someone save on time continuing to look for the answer,
... it appears as though this one probably took input from several different sources to get to the bottom of this issue. When facts are coupled with well thought out theories, this forum can be a great tool for all

Canon USA's and CINC's (Canon Inc., Japan) investigation had led to the belief that replacement of the clutch would be the resolution to this problem. In an effort to bring the latest information to the field, we decided to post what we knew at that time. However, the investigation was not complete. New information, gathered from our investigation, has yielded a greater depth of understanding which has led us to the following update to this problem. Please note the following:

We looked closely at how many machines use this clutch and also at examples of the same model number at different locations. Based on the results of this analysis, we determined that the most effective and quickest way to resolve this symptom is to update the DC Controller PCBs. This was mentioned earlier as a possible remedy, but was not, at that time, a definitive resolution. Beta testing was being done concurrently at the time of Bill's posting. We now feel this will be an effective solution to this problem. You can expect to see an update program to start soon

All of this is from the Canon forum, Such a wierd problem I read up on it. I would replace the dc controler and the paper deck one feed assembly if you can or at least the clutch. Good luck! You need that revision dc controler, You could contact Nation-wide repair and see if they can update or exchange for yours.

Posted on Jan 17, 2009


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