Shading on a Canon IR3570

[CopierChick]

I have shading or smudging on a canon IR3570 copier but it's sporadic! The customer only seems to notice it mainly when printing checks on the copier. I have been able to make the copier reproduce the issue when printing the font list in the reports section and it's very minimal but still there. Any suggestions?
Fyi-
it's in an office with nice AC running
also had the fuser replaced about 25k copies and less than a year ago
had a new drum

[dan7777]

Re: Shading on a Canon IR3570

I have shading or smudging on a canon IR3570 copier but it's sporadic! The customer only seems to notice it mainly when printing checks on the copier. I have been able to make the copier reproduce the issue when printing the font list in the reports section and it's very minimal but still there. Any suggestions?
Fyi-
it's in an office with nice AC running
also had the fuser replaced about 25k copies and less than a year ago
had a new drum

Make sure they are using Canon toner. If they are look at the developer. Maybe magnet roller is caked up in spots. Looks like it is charge/developer/toner related to me.

[CopierChick]

Re: Shading on a Canon IR3570

Make sure they are using Canon toner. If they are look at the developer. Maybe magnet roller is caked up in spots. Looks like it is charge/developer/toner related to me.

I thought about bout the same thing but what's crazy is that I can run 10 pages with no problem and then run another set of ten and it shows up on 1 or 2 pages. Is also not on the entire page it's mainly down the right side. (It' messes up the area where the page numbers are when you run the ps font list from the reports page internally)

also so when I went out the first time they had it all over the paper just about & u could feel the toner was raised on the paper and not fused well. So I tried new paper first and the later seemed fine except for the right side that showed up smudged sporadically. So I adjusted for humidity and that seemed to help and make it less noticeable but I didn't want to adjust too much considering the issue is mainly in this one area and not the entire page.
Thanks

[blackcat4866]

Re: Shading on a Canon IR3570

I would take my meter and check the drum ground. With the drum unit installed, meter the metal edge of the drum to the frame ground. You should get ~0 ohms.

On the machine I worked on. when you removed the drum from the drum unit, you could see the blackened area where the drum ground had been arcing inside the drum. On this machine I pried off the rear drum cap. The brass drum ground was blackened and mostly gone. I formed a large paperclip into a five pointed star, with the tips touching the drum core, and the center touching the drum shaft. I applied a small dab of conductive grease to the center of the star, then glued the drum cap back on. After that it metered 0 ohms to frame ground, and lasted full yield.

=^..^=

[CopierChick]

Re: Shading on a Canon IR3570

I would take my meter and check the drum ground. With the drum unit installed, meter the metal edge of the drum to the frame ground. You should get ~0 ohms.

On the machine I worked on. when you removed the drum from the drum unit, you could see the blackened area where the drum ground had been arcing inside the drum. On this machine I pried off the rear drum cap. The brass drum ground was blackened and mostly gone. I formed a large paperclip into a five pointed star, with the tips touching the drum core, and the center touching the drum shaft. I applied a small dab of conductive grease to the center of the star, then glued the drum cap back on. After that it metered 0 ohms to frame ground, and lasted full yield.

=^..^=

This is another example from this morning. They can run 10 checks with no problem and then the next check will have this blurry area only in one area of the page.
Thanks

[charm5496]

Re: Shading on a Canon IR3570

which way is paper feed in relation to the text that is smudging?
Have you looked at the fuser unit and the cleaning roller? I know you stated it was only 25K, but if that cleaning roller is caked with toner or the film is an off brand I would inspect it.

[CopierChick]

Re: Shading on a Canon IR3570

which way is paper feed in relation to the text that is smudging?
Have you looked at the fuser unit and the cleaning roller? I know you stated it was only 25K, but if that cleaning roller is caked with toner or the film is an off brand I would inspect it.

I was able to replicate the issue when printing the font list under the reports section and that comes out from the tray set to LTR. I also took the good pages I had and ran them thru the doc feeder LTR direction and was able to replicate the issue. So it does it on copies & prints.

One of the first things I replaced when I went for the issue the first time was the silver cleaning (heat sink) roller on the fuser.
Thanks

[charm5496]

Re: Shading on a Canon IR3570

the other thing I remember from this model was the developer leaking due to poor seals on top of it where the hopper connects. There just is not enough foam up there. It is possible yours has never been upgraded and has been leaking all these years into the HVT for your developer and primary/transfer rollers. Also the cylinder on your developer unit could just be old and not hold the toner very well in that area.

[CopierChick]

Re: Shading on a Canon IR3570

Well went back to the customer and replaced the entire drum unit & the entire fuser unit and no change in quality. Checked the developer unit and Dev roller and saw no signs of unusual wear. Also wanted to note that the issue is on the trailing edge of the paper and at the back section of the machine.


In case it makes a difference this only happens when the paper is coming out LTR and does not show up on legal size or LTR-R, so clearly it's coming from something at the back section of the machine since legal and LTR-R don't use the back of the drum & other items.


Now here is where it gets weird, I hadn't noticed any issue before on the old fuser (and still have the same quality issue) but happened to notice that the new fuser didn't seem to engage completely so I checked the door and found that I could make the quality issue go away if I bent the hook holder latch on the door. I kept messing with it and found that I could make the quality issue come and go depending on the location of that latch...


I have included some more samples for reference
image.jpgimage.jpgimage.jpg

[blackcat4866]

Re: Shading on a Canon IR3570

Those doors do tend to sag, and the latch engages poorly, and even breaks or screws strip out. When I was rebuilding those fusers, there is a plastic piece that wears that's part of the latching mechanism. I personally have never noticed a quality issue associated with it. The enduser just says that the door opens up all by itself, or is difficult to close.

Congratulations on an interesting find. I suspect that there was some additional space, or reduced spring pressure at the transfer roller, that caused the image to scatter during transfer. =^..^=

[AHHANIFA]

Re: Shading on a Canon IR3570

Hi friends,

i am also having the same issue in my canon ir3570 machine. while i rubbing the print copy its getting erased. kindly help on this

[blackcat4866]

Re: Shading on a Canon IR3570

That's poor fusing. Have you examined the fuser? What media type are you using? =^..^=

[CopierChick]