Bizhub C350 - Printing quality problem - Gaussian blur and fade out

Le Wins

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Somebody from another forum mentioned a test which I will to try out.
Basically he suggests intentionally interrupting the printing process. The toner stays on the drums and belt, this way I can (hopefully) check where the blur occurs.
By the way yesterday I finally figured out how to remove the belt unit (but I don’t want to talk about it…) so now I can do this test. (Also I cleaned it, but it doesn’t help)
Anyway…
If I measure the time between the intake of the paper (from the side feeder) and the output of finished print, the procedure lasts 10-11 seconds, so I will try to cut out the power somewhere in the middle.
I’ll be back.
 

The Hat

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By the way yesterday I finally figured out how to remove the belt unit (but I don’t want to talk about it…) so now I can do this test. (Also I cleaned it, but it doesn’t help)
The belt, drum and ink carts are all disposable, they are replaceable consumables and therefore cheaper to replace than to repair, it doesn’t make any economic sense for a printer of that size and quality to be unreliable.. (It becomes a liability).

That’s the way the Laser printer industry operate.. They have no time for problematic printers, it makes for bad business practice.. Unless you spend quite a lot of money or sign a new contract, this printer will not work properly again..
 

Le Wins

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The interrupt test results:
The blur is already present on the drums. So, does it can mean that the drums worn out simultaneously? Or something even before that can cause this? What do you think?
 

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Le Wins

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The belt, drum and ink carts are all disposable, they are replaceable consumables and therefore cheaper to replace than to repair, it doesn’t make any economic sense for a printer of that size and quality to be unreliable.. (It becomes a liability).
Yeah I get it. That is the reason why I want to narrow down the possible cause.
If it a replaceable thing, well hurray! Getting a new part can make it a full all-purpose printer for our home (it is not intended to be a business printer, I forgot to say that)
If it is a part which affects from now the whole unit and can’t be fixed or changed then this will stay just as a… supplementary until the toners runs out. After that… maybe I let it go.
P.S.: This is more like a hobby for me, not a business issue.
 

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Getting a new part can make it a full all-purpose printer for our home
This problem is most likely, to be associated with the belt, but even if it is, you may not be able to get the parts from KONICA MINOLTA yourself, they maybe only available to the commercial trade..
100 marks for persistence..:thumbsup
 

Le Wins

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an additional thing

I was not convinced about interchangeability between the drums of the different colors so I tried it out.
The dimensions are the same so I changed the yellow drum with the black and in the end it still works. And it seems that it has no effects on the quality of the prints.
Also the fact that no error message appeared after I turned on tells me that the drums are not under the supervision of the control chips (which I guessed after I disassembled the imaging units).
And I guess the same applies to the belt in the image transfer unit.
 

Le Wins

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You gonna… smear your… underwear! (or make a facepalm)
Because I found the problem and also the solution!

I was searching for parts for imaging units to order one set to sort out the possible problem.
I made a list but before the order I decided to make every possible maintenance what is written on the troubleshoot pages and every maintenance on the web, which mentions blur and applies for my unit.
I done two things:
1. I cleaned the LED assy lens.
This maintenance is actually mentioned in the service manual and in this YT video. So I did it according them.
2. I cleaned the electrostatic charger wire (At least I think so):
In the previously mentioned video the lady also fiddles with the some white plastic sticks under the toners.
I did the same on my unit. I am not sure that they are the same thing in my case because the sticks in my unit haves different shape, color and they are a part of the imaging units.
The service manual didn’t mention any “electrostatic charger wire” only some “charge corona” so I dint know about it.

I don’t know which of these helped but the blur almost totally disappeared! Just the cyan makes still a little blur, so I give him another two cleaning strokes but that didn’t help anymore.

I never did this cleanings before. Firstly because I didn’t know about them, secondly because even after I uploaded the troubleshoot pages which ones mentioned blur, nobody suggested that possibility and thirdly… I never imagined that the previous owner would miss a simple thing, such as a non-invasive cleaning process.

Probably I will have to repair/change the LED for the cyan in LPH assy (or the charger wire/corona) in the future but for now, I am fine with it!

The blur was present from the beginning. I bought this unit this way in the hope that I will figure out how to repair it (just like with every used broken electronic I bought). The last owner told me (as he remembered) it slowly developed the blur, and then they lost the patience to maintain it further and put it in the heated archive/storage where it stayed 2 years.

I got some items along with it when I bought it:
1 used waste toner bottle
1 used paper dust remover (I think)
1 new ozone filter
1 used deodorant filter (I think)
1 nearly empty yellow cartridge
2 full/new black cartridges

I checked the local markets for compatible used/broken unit selling for parts. No interesting listing currently.

Hopefully I can squeeze out of it 100000-150000 pages before I will have to replace something (probably the first things will be ozone filter, dust remover or transfer roller) but before that I will probably change the LED or wire of cyan color after all, if any of those causing the remaining blur and if can find any compatible parts. Sadly I didn’t find any replacements for those so far.
So far found replacement for drums here an here as a 5 piece bundle, chips, belts (which I am not sure about the compatibility currently). Also found an image transfer unit for 280 but I like the idea more where I have to replace just the belt. Just have find a compatible one or figure out which models using the same belt.

Anyway, the mystery of the blur is solved for now. I hope this topic will helpful for others also. Probably I will return to this topic time to time.

Thank you guy for all the help/time you spent for helping me. If you visit our county says hi! I pay a round :D
 

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