Replaced K Imaging Unit - Still Print Quality Issues Bizhub C550

[jeremyb503]

Hey folks, thanks again for the great advice in the past, I have another one for you here :D

We are having a print quality issue, as you can see in the image below. I have replaced the K imaging unit and the 2nd transfer assembly. Any thoughts?

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[tech51]

Hey folks, thanks again for the great advice in the past, I have another one for you here :D

We are having a print quality issue, as you can see in the image below. I have replaced the K imaging unit and the 2nd transfer assembly. Any thoughts?

19895
Looks like a HV problem to me.

[jeremyb503]

Looks like a HV problem to me.

Not to be too stupid here, but is there are troubleshooting process for this?

[jeremyb503]

Is there anyone that could help me out with some troubleshooting steps here?

Thanks.

[blackcat4866]

For starters I'd try printing something internal, like a status page, configuration page, it doesn't matter what.
Do you see any image, or is it resolved? Scanner problem.

Next I'd start printing single color output pages, either by selecting the specific single color from the op panel, or by printing sample documents of Cyan, Magenta, Yellow, and Black. What colors are affected? If all, look at primary or secondary transfer. If only a single color primary transfer or the specific color imaging unit.

You got to narrow it down. Make more samples: copies black, copies color, prints black, prints in single color, etc, then post them. =^..^=

[jeremyb503]

Thank you very much for your reply!

I have attached a photo below. I used the Utility mode and generated test pages, so they are coming from the machines memory not from the scanner or from a computer. The issue appears on all of the CMYK test pages.

We replaced the second transfer assembly about 2 months ago and the K imaging unit a few weeks ago.

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[jeremyb503]

I should also note that the end of the sheet with the problems is the one that is closer to the operators side of the machine.

[blackcat4866]

Next, I'd emergency stop the machine with a full color image on the primary transfer belt. Look at the developed image. If it shows the image problem then you can rule out secondary transfer. The image hasn't made it there yet, leaving only primary transfer.

If the image is good on the belt, it's a secondary transfer problem. Look for a problem with the contacts, the fit of the door, the pressure springs, or just a damaged secondary transfer roller. =^..^=

[tech51]

The next step here is to generate a test print like the ones you have but stop the machine as the print is exiting. Then remove the transfer belt and see if the image is formed properly on that. If it is then its a second transfer problem. If not you may have a faulty belt unit. By the way make sure the machine is level front to back, just in case. Hells bells, just as I hit the submit button blackcat got in before me!! Still, good to see both sides of the pond are thinking the same way

[blackcat4866]

It's good to see that we're thinking along similar lines. =^..^=

[jeremyb503]

Not to ask to dumb a question here, but how do I do an emergency stop?

And by the way, thanks a million, I really appreciate the reply's.

[blackcat4866]

When you hear the machine start up, pop open one of the doors. It may take a few tries to figure out how long to wait before stopping it. I usually count in my head: one one thousand, two one thousand, three one thousand, ... like that. =^..^=

[jeremyb503]

Well you were right. I remembered that we still had the old second transfer assembly that we replaced a few months ago, I put it back in and viola the machine prints perfectly. kind of annoying considering that it was an OEM part.

Thanks for all the adivice looks like this problem is solved.

On another note I need some new rollers for the machine, you folks have any leads on where I should get them?

[blackcat4866]

If your not a dealer, we usually use Printer Toner Cartridges - Copier Toner Cartridges - Printer Parts & Copier Parts (http://www.precisionroller.com) for other brand parts. They have good selection. =^..^=

[jeremyb503]

Thanks again!

[anhlinh78]

Dear Friends,
I had problem similar to your situation. But I just had for Magenta unit. When I print from file test (4 colors), only have magenta unit print full magenta on the sheet.
So how should I do to resolove that?
Thank you very much and hope to hear you soon.
Linh Anh.