I have a Canon iR2570 which is producing prints with appalling quality. I've been through the service manual, but all of the print quality tests in there appear to be for very specific things (white lines in scanning direction, black marks at start of page etc). My problem is just that the print quality is terrible across the whole page. There are lines and smudges and various other things.
A scan of one of the configuration pages printed is available at http://dl.dropbox.com/u/315580/CanonIssue.pdf
I guess my question is really what to try first. I originally had an error to do with the patch image sensor, so took the printer apart to that area to clean that, and cleaned up a lot of other bits of toner lying around at the same time. I can't imagine that all of these problems are due to bits of toner lying around - it must be something more.
I have the same problem with all of the colours. I've taken out the drum during a print cycle and I can see the text of the page on the drum, but the drum is fairly dirty around the text. The text itself looks a lot sharper than it does on the page though.
A couple of questions:
1. I've tried to follow the instructions for taking out the drum unit, but both the instructions you gave me and the ones in the service manual I have talk about the ITB release lever, but my printer doesn't seem to have one of those! All it has is a small sort of spindle/axle sticking out, and then the black faceplate behind it (the one with two screws in it. It definitely doesn't look like the photo in F-7-54 in the PDF you gave me. I can provide a photo if that would help. I guess maybe the lever has broken off? If so, might that be part of the problem - if the spindle that should have the lever on it isn't in the right position?
2. Is there any way to view the ITB properly while printing? Again, my printer seems slightly different to the manual - I think there has been the addition of a finisher unit on the left hand side (its on a sort of rack-and-pinion system and moves up and down). I can't seem to find a sensible way to remove that, so the only way I've found to access the ITB is to take the scanner unit off the top, then remove the whole of the next unit down - and then I can see the ITB. Obviously, though, I can't do that while trying to print, as that involves removing the control panel and lots of other things! Is there a way to remove this finisher unit/tray thing?
You said you had an error code first and that you cleaned the sensor. which sensor was that that you cleaned. the one above the drum or the one behind the left cover. If the one above the drum and if this copy quality problem occurred after you cleaned the sensor, you might want to make sure you reengaged the itb release lever. Sounds like this might be your problem since you stated the image on the drum looks better than the one on paper.
Before you can slide the drum out You have to turn the ITB lever to move the belt out of the way. Once you put the drum back in you have to reengage it. If the drum gave you trouble coming out, you may have caused the primary roller to pop out of place or other damage.
From my point of view, the lever might be in a wrong position. It's in contact with the transfert belt. During a print cycle, the drum image seems to be ok but with dirt. This could be explained by the fact that the primary transfert is poor because the drum/ITB distance is "large". The dirt on the drum image is due to the contact between the lever and the ITB witch makes toner fall on the drum.
I think the lever was in the wrong place, and I've managed to get it back in the right place. From looking at it in more detail, I think the lever bit has actually broken off, but I managed to turn the spindle anti-clockwise with a pair of pliers, and it seems to have locked into position now.
The original sensor which I cleaned was the Patch Image Sensor, which was underneath the ITB, near the drum. Which sensor is under the left cover?
I've seen the video of the ITB elsewhere, but I can't seem to get access to the ITB as easily as it says in the manual, or as it shows in that video. The only way I've found to get access properly is by taking the whole scanner unit off the top, then taking the whole of the next layer down off (it slides forward to the front, and comes off with the tray on the left-hand side which moves up and down), and then I can get access to it.
I think what I have on the left is a finisher unit of some description - it moves up and down on some cogs as paper comes out on to it. However, the cog system that it moves up and down on seems pretty well fixed in to the rest of the assembly. Is there a way to remove this moving tray, so that I can get access to the ITB while the printer is working?
The image quality issue occurred before I removed the drum to clean the patch sensor, so I don't think it was me damaging the drum/internal components while taking things out.
Thanks for the link to that document - I managed to get the finisher off properly and get to see the ITB during machine operation. I think I've got a lot more information now that should help in diagnosing the problem.
Basically, the image is coming up on the ITB properly - almost perfectly. There are a few drop-outs here and there, and a few lines occasionally on the large expanses of colour on some of the test sheets. Things like the grid pattern (test sheet 6) come out very sharp on the ITB. However, they are still coming out very poorly on the paper.
It looks like the problem must be somewhere between the ITB and the finished print coming out of the machine. From my understanding of the service manual that means the fixer, or the secondary transfer roller. Does that sound correct? If so, how would you recommend checking the operation of these parts? Is there some way that I can get access to those bits while its printing and see at what stage it goes wrong? (I somehow doubt that, given that the fixer is at about 200 degrees!). Or alternatively, can I adjust the secondary transfer rollers somehow and see if that fixes it?
Thanks for all the help, I think we're getting somewhere now :-)