LaserJet 4500 Print quality issue

[Steve Mackie]

Having trouble with my ColorLaserJet 4500N. When printing photographs, there
are horizontal lines through the picture. Almost looks like shade variation
lines. Toner is good, ITB is new.

Not sure how exactly to describe what the output looks like. The engine test
looks fine, the demo prints are better, but lines are still somewhat
noticeable. They are also noticeable on the config print.

The service manual is pointing to the drum unit, but there is 30% life left
on it.

Steve

 

[Tony]

Having trouble with my ColorLaserJet 4500N. When printing photographs, there
are horizontal lines through the picture. Almost looks like shade variation
lines. Toner is good, ITB is new.

Not sure how exactly to describe what the output looks like. The engine test
looks fine, the demo prints are better, but lines are still somewhat
noticeable. They are also noticeable on the config print.

The service manual is pointing to the drum unit, but there is 30% life left
on it.

Steve

Steve
Can you measure the distance between the lines precisely and let me know?
It will help determine the cause.
Tony

 

[Steve Mackie]

Having trouble with my ColorLaserJet 4500N. When printing photographs,
there

Steve
Can you measure the distance between the lines precisely and let me know?
It will help determine the cause.
Tony

In this case tony, they are equal to the scan lines. 1mm wide.

Steve

 

[Tony]

In this case tony, they are equal to the scan lines. 1mm wide.

Steve

Steve
Sorry for the delay in replying, I have been doing some research into what is
in my experience an unusual problem.
Firstly let's be sure we are both using the same terminology. These lines, are
they horizontal in the way that the paper leaves the printer, in other words
left to right on the paper as it emerges? If so then at first glance It does
not appear to be a drum problem but it is possible that the teeth on the drum
gear have worn and there is some rotational backlash that is causing the
problem. The other thing that I have discovered but not persoanlly seen is that
one of the gears in the drive train in the printer has worn teeth and is
causing the same problem.
Shade variations can be caused by one of the toner cartridges also with
backlash. Very hard to pick but you mention you have the service manual, there
is a section tha helps to diagnose toner cartridge issues.
The ITB can probably never cause this so I would expect that is not an issue
unless the problem started when you installed it???
Sorry, without sesing an image of the problem I can't offer any more ideas. Any
chance you could post one to something like http://rapidshare.de , it is free
and a good medium for this type of problem?
Tony

 

[Steve Mackie]

Sorry for the delay in replying, I have been doing some research into what
is

in my experience an unusual problem.
Firstly let's be sure we are both using the same terminology. These lines, are
they horizontal in the way that the paper leaves the printer, in other words
left to right on the paper as it emerges? If so then at first glance It does
not appear to be a drum problem but it is possible that the teeth on the drum
gear have worn and there is some rotational backlash that is causing the
problem. The other thing that I have discovered but not persoanlly seen is that
one of the gears in the drive train in the printer has worn teeth and is
causing the same problem.

Yes and I'll take a look for gear wear.

Shade variations can be caused by one of the toner cartridges also with
backlash. Very hard to pick but you mention you have the service manual, there
is a section tha helps to diagnose toner cartridge issues.
The ITB can probably never cause this so I would expect that is not an issue
unless the problem started when you installed it???

This issue was there before and after I installed a new ITB.

Sorry, without sesing an image of the problem I can't offer any more ideas. Any
chance you could post one to something like http://rapidshare.de , it is free
and a good medium for this type of problem?
Tony

Here's some pictures of a photo I printed:
http://users.eastlink.ca/~smackie/printer/IMG_0882.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0883.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0884.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0885.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0886.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0887.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0888.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0889.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0890.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0891.jpg

Steve

 

[Tony]

Yes and I'll take a look for gear wear.


This issue was there before and after I installed a new ITB.


Here's some pictures of a photo I printed:
http://users.eastlink.ca/~smackie/printer/IMG_0882.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0883.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0884.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0885.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0886.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0887.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0888.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0889.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0890.jpg
http://users.eastlink.ca/~smackie/printer/IMG_0891.jpg

Steve

Steve i have looked at all of these and am struggling to see any printer
related problems, can you provide a scan of the internal demo page?
Tony

 

[Steve Mackie]

Steve i have looked at all of these and am struggling to see any printer

related problems, can you provide a scan of the internal demo page?
Tony

Never thought of firing up my scanner. Damnit.

This is a partial scan of the same picture:

http://users.eastlink.ca/~smackie/printer/scan0006.jpg

You can defiantly see the horizontal lines.

Steve

 

[Tony]

Never thought of firing up my scanner. Damnit.

This is a partial scan of the same picture:

http://users.eastlink.ca/~smackie/printer/scan0006.jpg

You can defiantly see the horizontal lines.

Steve

Steve
Got to be honest I have no idea what that could be, in many years of printer
work (mainly laser) I have not seen anything like this, but I'm intrigued.
My guess, and it is only a guess, is gear backlash (worn teeth, the wear might
be very slight and hard to see).
But first, having said that, there is a slight indication of a repetitive
defect in the scan but the subject matter of the photo makes it hard to be sure.
If you want to do a bit more work I am happy to see what I can come up with.
Try generating two documents.
A portrait (must be portrait) A4 or letter document (using word, excel or
similar) with five vertical bands about 1/2 inch wide the full height of the
page. The bands should be Black, mid gray, Cyan, Magenta and Yellow.
And a portrait light gray page, full width and full length (or near enough).
If you can print, scan and post them I think they might tell a story. The
higher definition the scan is the better. But I will need to see the whole
page. The distances between repetitive defects is of paramount importance with
lasers hence the need to scan the whole page.
Tony

 

[Steve Mackie]

Try generating two documents.

A portrait (must be portrait) A4 or letter document (using word, excel or
similar) with five vertical bands about 1/2 inch wide the full height of the
page. The bands should be Black, mid gray, Cyan, Magenta and Yellow.
And a portrait light gray page, full width and full length (or near enough).
If you can print, scan and post them I think they might tell a story. The
higher definition the scan is the better. But I will need to see the whole
page. The distances between repetitive defects is of paramount importance with
lasers hence the need to scan the whole page.

I printed those two pages. The one with the bands has the same horizontal
stripes, however, no stripe in the black or the yellow (or at least they
aren't noticeable in the yellow). The grey, cyan and magenta strips have the
stripes, not as noticeable in the magenta.

The full page light grey really tells a story. There is a faint black
vertical stripe where the black and grey strips were on the previous print.
One of the full page ghosting causes is a worn drum unit.

Also, there is a repetitive defect that appears between 37mm and 40mm. More
so at 40mm. This, according to the service manual, points to the charge
roller or the ITB cleaning roller. Now, the ITB is brand spankin' new and
the drum is old. I ordered a new drum earlier today, should be here in a
week.

Also, the full grey page seems darker on the right, or is it left? Can't
remember which way it came out.

I'm satisfied at waiting to see what a new drum does. Is there anything else
you can think of? I'll scan the pages tomorrow and post them.

Steve

 

[Tony]

I printed those two pages. The one with the bands has the same horizontal
stripes, however, no stripe in the black or the yellow (or at least they
aren't noticeable in the yellow). The grey, cyan and magenta strips have the
stripes, not as noticeable in the magenta.

The full page light grey really tells a story. There is a faint black
vertical stripe where the black and grey strips were on the previous print.
One of the full page ghosting causes is a worn drum unit.

Also, there is a repetitive defect that appears between 37mm and 40mm. More
so at 40mm. This, according to the service manual, points to the charge
roller or the ITB cleaning roller. Now, the ITB is brand spankin' new and
the drum is old. I ordered a new drum earlier today, should be here in a
week.

Also, the full grey page seems darker on the right, or is it left? Can't
remember which way it came out.

I'm satisfied at waiting to see what a new drum does. Is there anything else
you can think of? I'll scan the pages tomorrow and post them.

Steve

OK steve, if you post the images I will see if I can add any value to your
diagnosis pending the arrival of a drum kit.
Tony

 

[Steve Mackie]

OK steve, if you post the images I will see if I can add any value to your

diagnosis pending the arrival of a drum kit.

Here's the best I could do:

http://www.apicalconveyorsystems.com/scan0007.jpg
http://www.apicalconveyorsystems.com/scan0008.jpg

You should download them and view the whole page at the same time. Panning
in IE you can't really make anything out.

Steve

 

[Steve Mackie]

Tony,

Do a Google search for color laser printer banding. Apparently, it's a
function of the printer.

Steve

 

[Tony]

Hmmm yes that is possibly true, especially for 600 DPI printers like the 4500
but I have several customers with this printer that can produce images that
don't have this issue.
Let's see what the new drum does, it should at least remove the vertical band
(probable wiper blade failure).
Tony