[CQ] Konica c308 photo shows printing issue

[Scarekrow]

Hello,

So the machine is printing light at one side as shown, changed K drum b4 I realized it also did the same on colour, then changed transfer belt.

Sstill the same, thinking forward from the process the 2nd transfer roller all seemed ok but then if problem was that it would show good on the belt, so would I be right into thinking , it has to be the laser unit?

[JasonSBE]

Re: Konica c308 photo shows printing issue

The print head is a possibility. What firmware version are you using, or have you flashed it? I've seen some weird image issues come up that were fixed with firmware on the 8 series.

[femaster]

Re: Konica c308 photo shows printing issue

It does resemble a laser issue. If you haven't already, try stopping the machine in the middle of the job and see if the image on the drum surface looks the same.

[4Toon]

Re: Konica c308 photo shows printing issue

Defiantly the laser head clean all the mirrors in the laser unit. The main reason for that issue will be your rotating polygon mirror There will be dust or dirt on it. Clean and be carful not to scratch

[Toxic]

Re: Konica c308 photo shows printing issue

I have seen and done a lot of dirty poligon motor mirror on 4 and 8 series but never seen pattern like this.
Dirty poligon motor mirror ussualy have effect on top of the paper about few cm to do down and it have gradual change in density.
On this photo there is exact transition and too big area but you can try to clean laser anyway.

[Scarekrow]

Re: Konica c308 photo shows printing issue

It does resemble a laser issue. If you haven't already, try stopping the machine in the middle of the job and see if the image on the drum surface looks the same.

That would suggest the fault happens between the drum and the transfer belt, as both col and b/w drums did the same and I changed the belt, can I not say the fault is already on both drums and the only thing before that is the LSU?

[Scarekrow]

Re: Konica c308 photo shows printing issue

I have seen and done a lot of dirty poligon motor mirror on 4 and 8 series but never seen pattern like this.
Dirty poligon motor mirror ussualy have effect on top of the paper about few cm to do down and it have gradual change in density.
On this photo there is exact transition and too big area but you can try to clean laser anyway.

I will go back on Monday with a spare LUS and do some more checks, the machine is only 18 months old and not in a dusty office so I would be supprised, especially since they are sealed units.

[4Toon]

Re: Konica c308 photo shows printing issue

I will go back on Monday with a spare LUS and do some more checks, the machine is only 18 months old and not in a dusty office so I would be supprised, especially since they are sealed units.

Probably not a dirty Laser unit but wondering if its still not a laser issue in general. That is where i would start if you have a used one bring one with you when you go there.

[femaster]

Re: Konica c308 photo shows printing issue

That would suggest the fault happens between the drum and the transfer belt, as both col and b/w drums did the same and I changed the belt, can I not say the fault is already on both drums and the only thing before that is the LSU?

I was just wondering if the pattern was showing up on the drums as well. My thought was that if the drum pattern looked the same, that it would point even more to an issue with the laser. We have replaced a number of laser units on these 36ppm and under color 8-series for weird defects that cause issues similar to what you are seeing. We've had a defective laser unit create distorted images to the entire page on all colors, all the way to at least one case where it only affected 1 color. The issues seem random, but end up being resolved with laser unit replacement.

[Scarekrow]

Re: Konica c308 photo shows printing issue

I was just wondering if the pattern was showing up on the drums as well. My thought was that if the drum pattern looked the same, that it would point even more to an issue with the laser. We have replaced a number of laser units on these 36ppm and under color 8-series for weird defects that cause issues similar to what you are seeing. We've had a defective laser unit create distorted images to the entire page on all colors, all the way to at least one case where it only affected 1 color. The issues seem random, but end up being resolved with laser unit replacement.

Thanks, I will do another check today before I feel the need to swap the LSU, I will check the image on the drum if I can catch it in time,

[Scarekrow]

Re: Konica c308 photo shows printing issue

Thanks, I will do another check today before I feel the need to swap the LSU, I will check the image on the drum if I can catch it in time,

Solved, went in yesterday to do more tests and the print patterns were all ok, I think what threw me off was checking for coverage when copy from the glass, this seems to over whelm the ccd and cause blanching giving a false impression of fading, when I later emailed the customer to ask if the same happened on printing he said yes, however he was maybe seeing something that might have been due to one of the IDC sensors reading low, so cleaned that and all seemed ok.

[Scarekrow]

Re: Konica c308 photo shows printing issue

2nd update, Customer rang back with same issue, which I have isolated to the scanner as its ok on print, so I cleaned all the optics and checked the mirrors, all seemed ok, but the images were still faded at one end of the copy, so I did a copy in landscape to see if that eliminated the issue but no, it was still faded down one side, even in land scape, I tried to do a graduation adjust but the machine came up with "pattern NG" does this move the problem then into the CCD ?

[Scarekrow]

Re: Konica c308 photo shows printing issue

PS I also did a FW update using X4 version.

[Synthohol]

Re: Konica c308 photo shows printing issue

if you dont mind, just for shits and giggles, lift heavily on the front left corner of the scanner and make a full size color copy.
ive seen scanner beds bent or trapazoided causing that image you first posted.
just a hunch.

[Scarekrow]

Re: Konica c308 photo shows printing issue

if you dont mind, just for shits and giggles, lift heavily on the front left corner of the scanner and make a full size color copy.
ive seen scanner beds bent or trapazoided causing that image you first posted.
just a hunch.

There is no sign of any damage, the prints that are produced in the area thats faded are perfectly in focus.