Good morning, it's a Konica Bizhub C452. Although it's a somewhat old machine, it only has 43,000 prints. The yellow stains appear only in the yellow color, as if the drum wasn't completely erased. The cleaning blade on that unit has already been replaced. Any ideas? Thanks for your time.
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No disrespect, I have to ask are you a new technician?
First thing is you should change the "complete" drum unit not just blade. You can rebuild drum units with aftermarket parts but you also install new drum along with cleaning blade. Plus you need to change chip so machine will stabilize and calibrate. Bottom line is you need new yellow drum. -
You should be able to swap the yellow drum unit with the magenta or cyan drum unit to see if the problem follows to the swapped color. If it does, there must still be an issue with the drum unit. FWIW, swapping in a whole new unit will avoid a few more issues than just doing a complete drum unit rebuild as copyman mentioned.
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Okay, I'll change the drum units. I'll keep you posted. Thanks for your valuable feedback.Comment
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I replaced the yellow drum with a cyan one, and the problem persisted. The problem was the yellow erase lamp. I replaced it, and the problem was solved. Thanks again for your time.Comment
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I printed three images and the problem returned. The yellow spots persist. I replaced the drum, cleaning blade, and eraser lamp in the imaging unit. It's as if the yellow drum is still loaded with the yellow part of the image, as if the eraser lamp's power isn't enough to erase it.Comment
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KMFLT is correct the C452 uses imaging units. I missed that is was a C452. Thought it was a C454. I would NOT try and rebuild image units. I've done it before but with little success. Since that is an older model you should be able to find good prices online for genuine Kon/Min IU's.
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What I did to see where the problem really was, was to remove the drum from the cyan unit, and place it in the yellow image unit, and I put the yellow drum in the cyan unit. I also changed the erase lamps, the ones that come in the lower part where the drum-developer unit goes, and there the problem with the yellow spots continues, it seems that the erase lamp does not "erase" the image from the yellow drum in its entirety.Comment
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Replace Your Drum And Blade , Or If U Don't Want To Replace Your Drum. And Blade ! Increase Image Background Adj =
{Call the Service Mode to the screen} {Imaging Process Adjustment} -> [Image Background Adj}Use the [+] key For Y Color to change the setting valueTo 5 ] - And Go Back To Imaging Process Adjustment And Touch Start Button To complete. You JobComment
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Are you using Original Konica toner or a compatible?Larhal
Retired
If all else fails read the Service Manual!
If that fails, meet me at the pub and we will discuss it.Comment
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Graham is that you mate?Comment
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I was also thinking of the 4-series in my head, my apologies for the dubious advice! Glad you solved the issue.Comment
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The last thing I did was move it and set the value from 7 in service mode - image adjustment process - transfer voltage fine adjust - to 7, and the yellow spots disappeared. I know I need to replace the drums. Even though this machine is old, it doesn't print many copies. The strange thing is that the imaging units are very worn, and almost all of them need developer powder. The TCR value averages 8 - 8.9 for color and 12.5 for black. Therefore, the print quality is lacking.You do not have permission to view this gallery.
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Developer in old even not over used units suffers from deterioration and losses its ability to attract toner.A tree is known by its fruit, a man by his deeds. A good deed is never lost, he who sows courtesy, reaps friendship, and he who plants kindness gathers love.
Blessed are they who can laugh at themselves, for they shall never cease to be amused.Comment
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