Image "repeat"

[kingarthur]

Hi

We've got a C750i Accurio, which they are doing heavy solids. The "white" image, is being repeated. We're using all genuine KM consumables, C count is 50K, K count is 44K. I've turned HR temperature up and down, I've turned off "Smart Fusing Control". Because it's a print from the PC, I can't print in single colours, apart from grayscale. I've printed in grayscale, it's not as bad. would've liked to have printed it in Magenta, Yellow and Cyan. I've now got this image on my USB, and have tried it in several machines, and it does it on every single one.

Hopefully I've managed to attach the image.

[tulintron]

It could say the size of the sheet or the distance at which the image is repeated. It would help a lot.


But, analyzing the image, I would shoot in drum unit.

[tsbservice]

Anytime I hear image/fault repeat the following question pops up - what's the distance?

[blackcat4866]

I would make a wild ass guess that that is a drum interval: ~96mm". I would suspect poor charge cleaning on one of the drums. Maybe poor drum ground.

It would be informative to make digital samples in Yellow, Magenta, Cyan, and Black Only. If you narrow it down to a specific color CMY, you can swap around drums to narrow down which one is the cause. Is it 96mm? =^..^=

[kingarthur]

I would make a wild ass guess that that is a drum interval: ~96mm". I would suspect poor charge cleaning on one of the drums. Maybe poor drum ground.

It would be informative to make digital samples in Yellow, Magenta, Cyan, and Black Only. If you narrow it down to a specific color CMY, you can swap around drums to narrow down which one is the cause. Is it 96mm? =^..^=


Yep 96mm. unfortunately, I can't pin it down to a specific colour, it's a print file, and my only options for printing are "Autocolour", "Greyscale" or "2 colour". I've put it onto my USB, and again, only have options of "Autocolour" or "Greyscale".
my 1st thought was drum, then fuser, as I had no way of eliminating the drums, I thought I'd have a go at the fuser adjustments anyway. This seems to be a recurring problem on Bizhubs, even on new machines, it would appear that they can't clean/discharge the drum quick enough, when you have heavy solids and a white script

[raplma]

Looking at this from a printers perspective rather than a pro tech perspective... so could be barking up the wrong tree here...

I assume in the image shown it was printed left to right (SEF), and I am not commenting on the quality of the solid colour, simply a thought on the ghosting, which in my mind is due in part to the logo being white on a deep solid colour, and the machines not being able to deal with this sharp contrast in their current condition. In effect the toner from the white patch is being deposited second rotation round.

Seeing you mention that it does it on every machine you have tried it on, what I would try is rotating the image 180 degrees, so that the logo apsect is printed last. Either rotate the artwork, or you may have an option to rotate image depending on how you send the file to the printer. That may get the file printed without the repeat, while the quality issue gets sorted by a tech.

Another trick I have tried in the cases of some halftone printing that has drum related artefacts, is although the image is simplex, run the job duplex, so send the artwork through as two pages one being blank. You then print the job duplex, with either the first page being the image or the second page being the image, the non-printing pass gives the machine time to balance before the next image. Don't ask me why this can work but it does sometimes, this is just one of the many "tricks" you pick up from 20 years of being a printer.

Just a thought...

[Gift]

+1 for the drum unit, probably a limitation since it's produceable on other units - seems a little more charge remains on the unused drum surface after the erasing phase. Changing the image rotation is a good tip or try and use and set up a thicker paper type (= lowering the process speed). I'm surprised that none of my customers called this in yet (probable tomorrow because now I conjured it up lol).

Does it also happen on the lower speed i-series models? From my understanding the C650i/750i ist just a highly bred office engine since KM decided against further developing the C754e/C758/C759 branch.

[Drivee]

Hi, that is called ghosting. All printers have that, some of them less and some more. OPC unit cause this, this is very difficult job for every printer.
Try to print this page on any printer and yyou will se... G letter on different gray scale. Use A4 pritner. If anyone need A3, I will provide.


50513

[blackcat4866]

Looking at this from a printers perspective rather than a pro tech perspective... so could be barking up the wrong tree here...

Seeing you mention that it does it on every machine you have tried it on, what I would try is rotating the image 180 degrees, so that the logo aspect is printed last. Either rotate the artwork, or you may have an option to rotate image depending on how you send the file to the printer. That may get the file printed without the repeat, while the quality issue gets sorted by a tech.

Another trick I have tried in the cases of some halftone printing that has drum related artifacts, is although the image is simplex, run the job duplex, so send the artwork through as two pages one being blank. You then print the job duplex, with either the first page being the image or the second page being the image, the non-printing pass gives the machine time to balance before the next image. Don't ask me why this can work but it does sometimes, this is just one of the many "tricks" you pick up from 20 years of being a printer.

Just a thought...

Both sound like great workarounds! Unfortunately the typical MFP enduser cannot understand that machines have limitations, and may not be able to make a perfect reproduction of every possible image. Take for example, using neon RGB colors in the electronic original, then attempting to print them on a CMYK printer. We often hear: "... just fix it!", when the task is outside the capabilities of the device.

I do like to hear from printers on these topics. They bring a different perspective, and usually do understand that all things may not be possible.


+1 for the drum unit, probably a limitation since it's produceable on other units - seems a little more charge remains on the unused drum surface after the erasing phase. Changing the image rotation is a good tip or try and use and set up a thicker paper type (= lowering the process speed). I'm surprised that none of my customers called this in yet (probable tomorrow because now I conjured it up lol).

Does it also happen on the lower speed i-series models? From my understanding the C650i/750i ist just a highly bred office engine since KM decided against further developing the C754e/C758/C759 branch.

I like the idea of using Thick media type to slow the drum rotation ... perhaps allowing more time for the drum to discharge. I haven't seen this issue either ... but most of my machines are the slower speed. I don't have any of the C750i's. =^..^=

[kingarthur]

I tried setting the paper to Thick 3,to slow it down, it still did it, however, rotating it 180, seems to have solved it, it's happening on all models, fast and slow

Sorry if I'm seeming a bit "thick" at the mo....and asking stupid questions....been a bad year, re depression etc...now getting divorced because of it....my head is up my arse up a bit, and sometimes finding it difficult to think logically....

Thank you everyone for your suggestions :)

[blackcat4866]

Try these:

=^..^=

[Zesti]

Though never noticed such in KOnicaMinolta, I happen to be working on a Ricoh Press C751 and customer took some printouts and I noticed same thing on prints with Dark Cyan background. There was same image repeat thing of white writing at one portion of print only. It was 13x19 sheets with multiple same images and it happening at starting images only. The operator of the machine mentioned to me that it if file problem not printer....:confused:

[raplma]

Both sound like great workarounds! Unfortunately the typical MFP enduser cannot understand that machines have limitations, and may not be able to make a perfect reproduction of every possible image. Take for example, using neon RGB colors in the electronic original, then attempting to print them on a CMYK printer. We often hear: "... just fix it!", when the task is outside the capabilities of the device.

...don't get me going on this one, I've probably have this conversation at least once a week since changing to digital from Litho. Back in the day we had four B1 Litho presses, as our market has changed so have we and today have two KM presses and one MFP (because you can chuck any junk through it!) With the public I don't mind the, "it looked different on my screen"... it's the professional designers who have done work for a customer and it's not CMYK colourspace who say it looked far better on my mac, and you go along the lines... does additive and subtractive colour rendering ring any bells, what standard is your screen calibrated too... and they look at you as if you're the dunce. And then it's our Litho friends who we do work for because it's not economically worth while doing the job Litho, and the artwork is 20 years old and created for film, so it's all tints of a spot PMS colour. Why can't you match the spot colour...why is the tint not looking right... here we go again. Of course there are all kinds of tricks to get the best you can, modern digital presses are far better at colour rendering and I always like a good challenge! :cool:

[raplma]

I said you shouldn't have got me started...
I've just had come to mind an opposite example.
We do a lot of wedding stationery and a young lady dropped in with an invite she'd done, with a beautiful line drawing. She'd bought some textured board and finding her printer couldn't feed well dropped in. I printed a couple off and had the, it doesn't look the same, comparing what her printer had done compared to ours. I said you're asking me to get our £100k printer to match the quality (poor) of your £100 printer... Yes she said...

[tsbservice]

I said you shouldn't have got me started...
I've just had come to mind an opposite example.
We do a lot of wedding stationery and a young lady dropped in with an invite she'd done, with a beautiful line drawing. She'd bought some textured board and finding her printer couldn't feed well dropped in. I printed a couple off and had the, it doesn't look the same, comparing what her printer had done compared to ours. I said you're asking me to get our £100k printer to match the quality (poor) of your £100 printer... Yes she said...

I almost spit my sip on that. How funny :cool: