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kombo2
05-01-2021, 09:32 PM
Since some time there are white dots in the prints, even visible when text is printed. Even more visible is this in grey prints. Additionally there are some lines visible, especially in grey areas. Does anyone know what the cause of these problems might be? Is it a cleaning issue or is there a part that has to be replaced? The device is used very little (~5000 pages printed). Attached scans of grey, black and cyan prints.

blackcat4866
05-02-2021, 12:13 AM
Were I to guess, I'd say that you've got label adhesive on the black drum. How it got transferred from the primary transfer belt without leaving it on the belt ... I don't know.

The photoconductor or "drum" is an optical device. Light exposes the imaged (dark) areas of the drum, and anything stuck on the surface acts like a filter, leaving white anomalies at 96mm intervals. The lighter lines in the feed direction are probably just a dirty black laser slit glass.

If it were me, I'd remove the imaging units, and use the wand to clean the laser slit glasses. I would then re-install the C/M/Y imaging units. Then I would clean whatever is stuck to the black drum. This is the tricky part, since the drum is inside the imaging unit, and you can only see a small part of it at a time. I would would use paraffin lamp oil to clean a small area with a cotton pad and gently wipe only (don't scrub). Then rinse with alcohol on a cotton pad. Rotate 1/10th of a rotation and repeat, until you get all the way around the drum.

There will be residue on the drum, so you'll see a pattern that repeats at 96mm over the next 50 to 100 prints, until the drum wiper has squeegee'd off the residue.

=^..^=

copier tech
05-02-2021, 09:47 AM
Since some time there are white dots in the prints, even visible when text is printed. Even more visible is this in grey prints. Additionally there are some lines visible, especially in grey areas. Does anyone know what the cause of these problems might be? Is it a cleaning issue or is there a part that has to be replaced? The device is used very little (~5000 pages printed). Attached scans of grey, black and cyan prints.


From your samples it looks like you need to replace the image unit. These can be replaced by the end user (you)

From personal experience attempting to clean the unit only makes the issue worse.


Konica Minolta IUP22K Black Imaging Unit A3GP01D

tsbservice
05-02-2021, 12:43 PM
Agree with other guys. First remove black imaging unit and clear laser slit glass if images aren't improving replace black IU.

kombo2
05-03-2021, 08:06 AM
Thank you for your answers and ideas!

I have tried cleaning the black opc drum with alcohol and a cotton cloth as a first step, because on inspection the white spots were visible as clots of toner that were stuck to the drum. Result is that the white spots are gone : ). If they come back after some time then i will probably replace the black imaging unit.

Unfortunately the vertical lines are still there, in the grey prints very visible, in the cyan only very faint (see attached scans). I have wiped what i think is the laser slit glas but that looks clean, see attached photo. I was thinking that maybe the vertical lines do not originate from the opc drum, but maybe from the transfer belt? I think at some point i read that these devices are known for damagin transfer belts. I have attached a photo of the transfer belt, there are some lines visible, but i am not sure if they are responsible for what is visible in the prints. What do you think?

blackcat4866
05-03-2021, 06:14 PM
That is the laser glass that you have photographed. It's unlikely that the inside of the black laser is dirty, and the inside of the color lasers are all clean.

It's possible that it's a developing issue ... requiring replacing the black imaging unit. =^..^=

tsbservice
05-03-2021, 07:42 PM
It's not hard to remove all toners, WTB all IUs and ITB itself. Then post a picture of whole belt.

kombo2
05-03-2021, 10:34 PM
Here are 2 photos of the transfer belt. Can you identify if this looks normal or not?

blackcat4866
05-04-2021, 12:07 AM
Here are 2 photos of the transfer belt. Can you identify if this looks normal or not?

From what I can see, the primary transfer belt looks fine. It would affect all colors equally. =^..^=

kombo2
05-04-2021, 06:53 PM
I think you are right, the faint vertical lines in the color prints are probably more imagination than really there. I will try and replace the black imaging unit, after that i hope the quality will improve significantly. I will give feedback after the replacement if that fixed the problem.

Thank you for your help!!

tsbservice
05-04-2021, 07:22 PM
I think you are right, the faint vertical lines in the color prints are probably more imagination than really there. I will try and replace the black imaging unit, after that i hope the quality will improve significantly. I will give feedback after the replacement if that fixed the problem.

Thank you for your help!!

From memories black imaging unit for this model is relatively cheap.

kombo2
05-06-2021, 11:17 AM
It costs about 100 € around here. I wouldn't have called that cheap, but i guess it could be worse ^^

By the way, does someone have a recommendation for a good lint-free cleaning cloth that is available in Europe?

kombo2
05-08-2021, 12:07 PM
The black imaging unit replacement has arrived and i have exchanged it. Your suggestions were correct, now the vertical lines in black prints are gone (see attached scan).
49124

I had some problems at first where the grey prints with new imaging unit showed some white spots. Also when i opened the packaging of the imaging unit, it looked like there was yellow toner on the drum, is that normal for a brand new imaging unit?
49126


After gently wiping the drum the spots that appeared in the first prints disappeared, but on a horizontal line on the drum it looked like there are small dots of black toner stuck to it (see picture of drum). I could not remove those by gently wiping the drum. So at the moment there are some tiny white spots in the grey prints, almost invisible, but i fear those will get bigger over time and maybe even the lines will reappear. Do you have any idea what these small dots on the drum might be or what the cause for this might be?
49125

blackcat4866
05-08-2021, 02:23 PM
Yes, it's normal for all drum blades to be primed with yellow toner, on all manufacturers, all models.

The small defects you see are on the drum surface. The will not get worse, and they won't go away. You're only recourse is to order another drum (or live with it). Do not try to polish or remove the defects, you will make it worse. =^..^=

kombo2
05-08-2021, 09:43 PM
That about the yellow toner is good to know, thanks!

Any idea what might cause these defects, i think similar ones were on the old drum. I am not sure if those defects have already been there when i got the imaging unit, i suspect my printer is causing those.

blackcat4866
05-08-2021, 11:12 PM
Maybe somebody here knows more about the manufacture of organic photoconductors ... but I suspect that it's a defect in the outer clear-coat on the drum. I've seen such things before. They usually do not affect image quality. =^..^=

kombo2
05-13-2021, 03:34 PM
Ok, i will observe if the small white dots get bigger or more over time and for now hope they won't.

Thanks a lot!

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