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occus
09-19-2014, 03:57 PM
Hi, have someone a idea how to fix this problem?
Have a look on the jpg. Format A3

There are stripes every 5mm... on black print, on half tone. I mean the tiny darker stripes not in feed direction.

What i have done to fix...
New Drum, DV black, transferbelt, transferroller, clean the laserunit (disasembled and cleaned), played around with the voltages... clean the contacts from drum, dv and trans-belt-roller.
Nothing helps.

After switching back the old units, the first print was better, after the stripes come back darker.


Can it be a mechanical problem from the drive?
or should i try to change the boards? the prcb or the HV?

picture on external hoster
http://s28.postimg.org/l89z0sdex/Stripes.jpg (http://postimg.org/image/l89z0sdex/)


hostet from copytechnet (slow)
26492

minimerlin
09-19-2014, 08:44 PM
Looks like pitch lines from drive gears/motors of the image unit. Have a check of these areas.

miguell
09-30-2014, 10:42 AM
Hi, have someone a idea how to fix this problem?
Have a look on the jpg. Format A3

There are stripes every 5mm... on black print, on half tone. I mean the tiny darker stripes not in feed direction.

What i have done to fix...
New Drum, DV black, transferbelt, transferroller, clean the laserunit (disasembled and cleaned), played around with the voltages... clean the contacts from drum, dv and trans-belt-roller.
Nothing helps.

After switching back the old units, the first print was better, after the stripes come back darker.


Can it be a mechanical problem from the drive?
or should i try to change the boards? the prcb or the HV?

picture on external hoster
http://s28.postimg.org/l89z0sdex/Stripes.jpg (http://postimg.org/image/l89z0sdex/)


hostet from copytechnet (slow)
26492

I saw on some forum that will best compatible toner

BennyAU
10-02-2014, 04:37 AM
looks like the laser unit itself causing those 5mm lines, I have seen this on quite a few models and it always looks the same

thankfully most people don't even notice.

Phrag
10-02-2014, 07:43 AM
What Benny said.

Every tiny imperfection on the Drum and Mag Roller surface comes out on those 128 halftones. But I've never had any ring about them.

They aren't distinguishable on black text, and unless your printing large blocks of K only Gray, they won't be noticed.

pgramolini
10-03-2014, 12:26 AM
Quite possibly the print head... Let me know how it works out.

occus
10-13-2014, 11:34 AM
thanks all for feedback!

I talked with a other technician who had this problem too. He told me he changed all the electrical boards and the problem persists.
But this lucky guy changed the machine (rent after 4.5 years)... i can't change, it sould be run for a year again.

@miguell
we use never compatible toner.

Yes, next step is to change M18 drive motor black drum or the PH-Unit.

EarthKmTech
10-13-2014, 11:55 AM
make sure the fusing loop sensor isnt snapped off or the fusing unit will run too fast and tug on the paper and upset the speed of the transfer belt.

occus
10-14-2014, 11:49 AM
thanks for your hint @EarthKmTech

But should i see the problem on the other colors too if it's the fuser?
The other colors are ok...

The fuser is changed anyway, broken surface of roller.

occus
10-30-2014, 01:31 PM
It is not the Laser... tested

Picko63
12-08-2014, 07:32 AM
Hey Occus,

Did you happen to get this sorted? Have a similar issue - the bands only really show up on halftones.

Any tips greatly appreciated.

Cheers,

Bruce.

occus
12-08-2014, 04:29 PM
Sorry i have no solution...
I think it is the drive...

SteppK3
01-21-2015, 11:03 PM
Hey occus or anyone else, im having the same issue. in my particular case black halftones show the worst, then cyan, then magenta, and yellow is indistinguishable. ive changed the transfer belt unit and 2nd transfer roller but the problem persists or worsens. Also, ive noticed that the issue is more noticeable the lower the Density on the halftone. Any updates to this issue would be greatly appreciated? thanks

allan
01-22-2015, 01:06 AM
sure this is only on black? on what gradation is that printed looks like 125. A C364 would do this because of the developer eating away at the waste box making it jumpy. If it is the motor or encoder you would get P-14 P-21 on this machine.

imihm
01-22-2015, 08:30 AM
Hi, have someone a idea how to fix this problem?
Have a look on the jpg. Format A3

There are stripes every 5mm... on black print, on half tone. I mean the tiny darker stripes not in feed direction.

What i have done to fix...
New Drum, DV black, transferbelt, transferroller, clean the laserunit (disasembled and cleaned), played around with the voltages... clean the contacts from drum, dv and trans-belt-roller.
Nothing helps.

After switching back the old units, the first print was better, after the stripes come back darker.


Can it be a mechanical problem from the drive?
or should i try to change the boards? the prcb or the HV?

picture on external hoster
http://s28.postimg.org/l89z0sdex/Stripes.jpg (http://postimg.org/image/l89z0sdex/)


hostet from copytechnet (slow)
26492

Hi there

Replace the CCD assy
Thanks

JDR
10-06-2015, 12:52 PM
Same issue there.

30851


I would have bet on HV PWB 1 but a previous message said bad fix.

Mr. Joshua
10-17-2015, 06:23 PM
Hi there

Replace the CCD assy
Thanks

For the less educated on here, this is nonsense. I can't stand watching time/effort wasted going down the wrong road.

Mally
10-17-2016, 02:29 PM
Howzit guys. Pitch lines is very difficult to correct and in all cases I've seen it never totally went away. But u can improve the lines drastically. The problem is caused because the k drum is engaged when making a greyscale print, which in test mode halftone is 1PC black. But u will notice a 4PC black is much better because all drums are engaged. In a 1PC print, the transfer belt is too loose because of the 1 drum only and it causes pitch lines. Therefore when all 4 drums are used the print looks better because the transfer belt is tighter. To improve this,choose 2 colour on your printer driver using black and blue. Pls note this will now be considered a colour print, so advise customer. Cool

habik
10-18-2016, 10:16 PM
Howzit guys. Pitch lines is very difficult to correct and in all cases I've seen it never totally went away. But u can improve the lines drastically. The problem is caused because the k drum is engaged when making a greyscale print, which in test mode halftone is 1PC black. But u will notice a 4PC black is much better because all drums are engaged. In a 1PC print, the transfer belt is too loose because of the 1 drum only and it causes pitch lines. Therefore when all 4 drums are used the print looks better because the transfer belt is tighter. To improve this,choose 2 colour on your printer driver using black and blue. Pls note this will now be considered a colour print, so advise customer. Cool

Well done.

Now wouldn't it be possible to adjust the slack on the paper loop so there is minimal drag like EarthKmTech suggessted?

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