bizhub 951 - vertical grey blurry lines

**zivv85** · 04-11-2021

There is a problem with our bizhub 951. It prints with blurry grey vertical lines which appear in random place of the sheet and repeat every 315 мм (approx.) This refers to the drum (which diameter is about 100 мм). Lines appear on both sides of the sheet (duplex printing) on all sorts of paper. After starting printing machine prints 3-5 minutes very well, then that lines begin to appear from very light (barely visible) to what you see on the included image.
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I found that if I vacuum the interior space between the drum and developer roller which is usually (in my case) uneven covered with toner - the problem is solved for a while. I also vacuumed the developer filter (with is located to the right of the developer unit). This helped even more. However, despite this, after a while (about 30-60 minutes of printing) lines come back and I have to disassemble the machine and vacuum it again and again.
The machine was run in 2014. It has only 560 thousand prints now. Nothing has changed in it till this moment. The previous 150 thousand prints (in the past three months) were good.

If my understanding correctly if I say that the developer is worn out and it can't hold the toner on the developer roller well? Toner spills down on the drum surface and that lines appear. Does it make sense? Or the problem can be with the damaged (worn) drum surface?

**blackcat4866** · 04-11-2021

Originally Posted by zivv85

1399d38f-4854-4b55-8538-36f5458ab487.jpg

If I am understanding correctly if I say that the developer is worn out and it can't hold the toner on the developer roller well? Toner spills down on the drum surface and that lines appear. Does it make sense? Or the problem can be with the damaged (worn) drum surface?

I'd put my money on the developer, yes. After 7 years, the developer may very well have degraded.

Do you know how to do a developer change? =^..^=