IR8070 gray background after multiple copies

[majickmerlyn2]

Help!

I have a Canon IR8070 at a customer account that is giving me fits. When making multiple images, the copies start off crisp and white. After about 15 or so images, there starts to be a gray background image that looks like corona being turned up too high on a IR5000. When I first noticed this issue, I went for what I thought was obvious, I replaced the primary corona unit and when that did not fix it, I replaced the development unit. The problem went away for a few days, then returned. Second round, I replaced the cleaning blade, vaccumed out all the excess toner, recoated the cleaning roller with new toner, replaced the pre-transer corona, replaced the transfer corona, and polished the drum. The issue has returned to day and the law firm the copier belongs to is getting antsy... Copier only has 1.3 million copies on it. I believe that this copier is write to black, which I do not have much experience on.

Any suggestions would be appreciated.

Jeremy Sweeney
Master Technician
Ricoh-USA

[zoraldinho]

Do you have still a problem if you turn off a potencial sensor?
Do you have last firmware installed?

Post a picture please.

[vigour]

are they using genuine toner?

[charm5496]

He works for ricoh so I doubt that it is Canon OEM toner.

[Herrmann]

First at all, you have to sort out if it is a laser or a charging issue.
Tape the dust shield glass with black tape 1cm and do the multicopy again, what happens?

[majickmerlyn2]

Thanks to all who posted on this thread. I did isolate that it was a charge issue. Taping the shield glass did not change my issue. I also tried the to turn the sensor off, to no avail. After a new dev unit, new drum, and some other headaches later, I found that I put in another primary corona unit, and the issue was gone. The primary corona unit that I had installed previously was rebuilt.

Interesting thing that threw me on this model is that it is write to black. If the same issue were happening on an IR5000, you would have seen light areas not dark.

Cheers!