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Makinbacon
02-02-2015, 04:11 PM
I was wondering if anyone has seen this before. This is a repeating pattern that looks to be digital not mechanical. We have replaced the following:
Image Transfer Unit
All Drum and Developer units
Laser unit
KMBS said to replaced the power supply... we did.
Next they say to do the memory. I personally do not think it's a memory issue. I have been wrong before...
Hopefully you can see the spots on the images attached. You may have to zoom in on the image to see them.

allan
02-02-2015, 05:22 PM
Does this appear on copies too?

Makinbacon
02-02-2015, 07:36 PM
Does this appear on copies too?

Yes. I forgot to mention that it only happens on color prints and copies. If a bw job is run its fine. It only has about 12k color on the counter. It feels like a symptom of something else. Like, if you do not run through the setup procedures it leaves lines on color copies. But this is copies and prints.

allan
02-02-2015, 07:58 PM
It does look like noise, are those spots black or dark grey are they raised? If i would change something to test it would be the MFPB. I give up that is too unreal.

allan
02-02-2015, 08:03 PM
Argg that does not make sense. Take a very high res image with a camera with plenty of megapixel.

allan
02-02-2015, 08:08 PM
Blank of all the other lasers slits with black insulation tape and run the same test. If its still there you can rule out any processing problem. unless they come out magenta ???

Makinbacon
02-02-2015, 10:51 PM
Blank of all the other lasers slits with black insulation tape and run the same test. If its still there you can rule out any processing problem. unless they come out magenta ???

We assume that the machine is putting the spots there. We also assume they are coming from the black drum because the machine is writing them there. But we replaced all of them. We did run yellow and cyan prints and got the same result with the spots. We removed the surge protector and it did not help. I scanned these images in on a C452. I tried different resolutions. I wanted a clear enough picture to see the spots but was worried about file size.

blackcat4866
02-03-2015, 02:00 AM
I know that you already replaced the drums, but the repetitive nature of the problem points back at the drum. what is the interval on the repeat? =^..^=

wseyller
02-03-2015, 04:26 AM
You say it doesn't happen with black only prints which makes me think the black drum itself is not the cause. I think the black primary transfer is engaged at all times. I bet the laser is writing this pattern to the drum. What Allan suggested is a troubleshooting method to help determine if that is true. If it is coming from the laser then you can eliminate half the machine. Because then you are looking are the laser unit, ribbon cable, prcb and MFP.board. You would eliminate everything involving the electrostatic process and fixing.

yianni
02-03-2015, 05:42 AM
I've noticed two interesting issues.
1.. In the first photo the blue area doesn't have this noise.
2.. It seems there is a repetitive pattern. The two areas marked as black rectangles, -in the second photo in magnification-, someone could see the same pattern of dots. Almost all color copiers use a method for identifying the serial number -in every color page- using yellow dots that are not visible with bare eyes. It seems, -in your case- like the yellow dots are replaced with black dots. I suggest to scan only a small area (e.g. 3x3 cm, 1x1 in) in the higher resolution, like 2400 dpi.

Foxhound
02-03-2015, 06:36 AM
A good look under a loop would help clarify what exact colors are being layed on the image. Check filters are good and start checking transfer voltages. also i have seen toner/dust coat the boards in the back layering on process chips causing unexplained quality issues.

Makinbacon
02-03-2015, 06:00 PM
A good look under a loop would help clarify what exact colors are being layed on the image. Check filters are good and start checking transfer voltages. also i have seen toner/dust coat the boards in the back layering on process chips causing unexplained quality issues.

We have replaced the MFP(Main) board already. I think I forgot to list that. I am inclined to agree with you that a loop may be out of adjustment. KMBS said to replace the Memory Module so that is next as it arrived yesterday. I suggested a factory reset. At least its under warranty and we get all these non consumables for free. I am posting for another tech at my company. I still think it is software/firmware related. Such as a setting or adjustment out of spec or tolerance.

Thanks for all the replies. Still open to suggestions.

EarthKmTech
02-04-2015, 09:10 AM
Id be considering replacement of the ssd module and a factory reset and reconfigure.

it looks a hell of a lot to me like its overlaying the serial number in the wrong colour in colour prints, it is supposed to be yellow so as to not be visible.

Makinbacon
02-04-2015, 05:03 PM
The tech did cover the black laser window and still got the dots. So The grey dots are a mix of CMY. Could this be caused by line noise? He has moved the machine to a different outlet on a different circuit and copy quality got worse. Black prints got blurry.

yianni
02-04-2015, 05:39 PM
The tech did cover the black laser window and still got the dots. So The grey dots are a mix of CMY. Could this be caused by line noise? He has moved the machine to a different outlet on a different circuit and copy quality got worse. Black prints got blurry.My english is not very well, and may I haven't explained it correctly. It seems it's the serial number used to printed with not visible yellow dots. It seems it's this https://w2.eff.org/Privacy/printers/docucolor/ .

EarthKmTech said: it looks a hell of a lot to me like its overlaying the serial number in the wrong colour in colour prints, it is supposed to be yellow so as to not be visible.

bigwul
02-04-2015, 05:52 PM
We have replaced the MFP(Main) board already. I think I forgot to list that. I am inclined to agree with you that a loop may be out of adjustment. KMBS said to replace the Memory Module so that is next as it arrived yesterday. I suggested a factory reset. At least its under warranty and we get all these non consumables for free. I am posting for another tech at my company. I still think it is software/firmware related. Such as a setting or adjustment out of spec or tolerance.

Thanks for all the replies. Still open to suggestions.

When he says loop - I think he means EYE LOUPE - magnifier so that you can check for repeat patterns.....not an adjustment loop.....just saying.....

Makinbacon
02-05-2015, 03:29 PM
My english is not very well, and may I haven't explained it correctly. It seems it's the serial number used to printed with not visible yellow dots. It seems it's this https://w2.eff.org/Privacy/printers/docucolor/ .

EarthKmTech said: it looks a hell of a lot to me like its overlaying the serial number in the wrong colour in colour prints, it is supposed to be yellow so as to not be visible.

That does look like what is happening. If that is what is happening why is it using all of the colors and how do we stop it? Maybe just roll it off a cliff. It won't print spots after that... lol

yianni
02-05-2015, 04:46 PM
That does look like what is happening. If that is what is happening why is it using all of the colors and how do we stop it? Maybe just roll it off a cliff. It won't print spots after that... lolYou are right, I don't know. I'm not a copier technician. Does the yellow printed well? Especially the light shades (0-20%).
I suggest to scan a very small portion in high resolution, you will see the exact colors and you will confirm it's the serial number. 2400dpi is like a eye loop magnifier. The attached photo is a 1 x 0.5 cm (about 1/2 x 0.2 in) of 16 points cyan letters.

minoltaed
02-05-2015, 06:04 PM
I would start with the memory. Some of the older color boxes would do some weird stuff. Memory always fixed the issues. Sounds like some things I have seen in the past.

Makinbacon
02-09-2015, 08:14 PM
I would start with the memory. Some of the older color boxes would do some weird stuff. Memory always fixed the issues. Sounds like some things I have seen in the past.

We replaced the memory. The tech is hesitant to do a factory reset for some reason. We are going to test the power outlet for noise. To see if that could be the cause of the problem. The damage is done so what ever part is cooked is what we need to find. We're hoping we can find the cause so the solution will present itself. If not we may have to have a KMBS rep look at it.

Makinbacon
03-10-2015, 07:28 PM
Update. We are replacing the SSD board today. If that does not fix it then they will have the KMBS rep come out so we can look into getting the unit replaced. I was hoping for a resolution to post but we will have to wait and see. I still think he should do a factory reset. I will mention it again.

Makinbacon
03-17-2015, 04:23 PM
Another update... SSD did not fix. The KMBS rep thinks someone is trying to copy currency on the machine. Or the machine thinks that. It will get worse each time an attempt to copy currency is made. There is a special way to reset it and only KMBS seems to know at this point. Our rep doesn't even know. I treating thought is that the repeating patter may contain info as to what the problem is. As if it is a code.

Makinbacon
03-18-2015, 04:06 PM
Well, we sent the samples to KMBS and they confirmed that is what it was. The customer tripped the copy protection. They are stating that the F.B.I. may get involved and the machine may be confiscated and an investigation may take place. Don't copy currency on a Konica Minolta, not even for educational purposes. This machine is at a college. I assume with digital rights management progressing in digital systems that copyrighted material may be the next thing to trip copy protection. As of now I assume it is only affected by currency. KMBS Tech support did not even know or if they did, didn't tell us what was going on. As a service tech this info is vital so we can address it A.S.A.P. So if you are servicing a Konica Minolta and see something like this that boards cannot fix, call your rep.

Thanks for your help!

Makinbacon
04-03-2015, 08:51 PM
Update....again. KMBS has come back to us and said they no longer think that this issue is due to copy protect. They are investigating further. Our tech has to go do a data retrieval. I will keep this thread updated because I want the right info for the next person who has the issue... sorry.

Blizzoo
04-04-2015, 11:26 AM
I just converted a Bk IU into Y one on a C252 a few weeks ago (lot cheaper than buying a Y unit ) and had those patterns in color mode but not in bw mode, until bk toner depleted from Y unit. Thanks to this thread i was sure that those patterns had to be visible and to not worry about them. This is first time doing this modification.

In your case I will be curious the results swapping the Y dev unit with M or another color to see if the dots changes in color.Before doing that i think is better seal the toner supply holes and disable New Release Detection mode, steps are in theory section in the manual.

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