I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?

thanks,

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

In article ,
Jim Adney wrote:

I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?

If it's worth the effort, you can find spray cans of the photosensitive
material to refurbish it.

Google around.

Isaac

That one, I believe, is meant to be changed out every so many thousand
prints. If you do find a way to resurface it, make sure to empty the used
toner reservoir.

jak

"Isaac Wingfield" wrote in message
...
In article ,
Jim Adney wrote:

I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?

If it's worth the effort, you can find spray cans of the photosensitive
material to refurbish it.

Google around.

Isaac

"Jim Adney" wrote in message
...
I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?


Don't touch the drum with bare hands or use liquid on it. Get a piece of
silk (a silk handkerchief) and gently polish the drum surface.all over.
Make sure your work surface is free from dust etc as these could be
attracted to the drum as you polish.

On Mon, 27 Sep 2004 19:32:57 -0500 "jakdedert"
wrote:

That one, I believe, is meant to be changed out every so many thousand
prints. If you do find a way to resurface it, make sure to empty the used
toner reservoir.

Yes, and I even have some spares here, but this problem occurs with
few copies (1300) passed thru the copier, and we're not even close to
what the lifetime of the drum should be. The surface of the drum does
not appear to have any damage to it, and I can't see anything on it
that would indicate a problem.

Now, let me add a complication: The periodic "dirt" lets me calculate
the diameter of the culprit, assuming that the paper moves along the
rollers without slipping. The calculated diameter is 19mm, while the
drum is 30 mm. There is a 19mm magnetic roller that feeds toner to the
drum, but nothing I do to it seems to have any effect on the dirty
printout.

OTOH, swapping the drum with one from another printer, while still
using the same 19mm magnetic drum, fixes the problem. So the problem
is clearly with the drum assy. If this is the case, then it seems to
me that this should be a problem that others are familiar with, yet I
don't seem to get any response from anyone who claims to be familiar
with this problem.

Can anyone tell me what goes wrong with printer drums? I'd also like
to know what happens to them if they get too much light on them.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Can anyone tell me what goes wrong with printer drums? I'd also like
to know what happens to them if they get too much light on them.

Jim-

Some companies recommend that you keep your copiers and printers away from
windows, so there may be some detrimental effect from light. More likely it is
that light leakage will interfere with the copy/print process.

As I understand it, the drum is coated with a photo-sensitive material
(selenium) that is electrically charged. It is exposed to an image (laser
light in the case of a printer) that dissipates the charge in relation to the
brightness of the light. In other words, a blank sheet would be completely
discharged.

The drum is then exposed to toner, which is attracted to the charged areas. It
then "rolls" the toner onto a sheet of paper, which is then heated to fuse the
toner.

After the print is made, the drum is wiped clean of toner, recharged, and is
ready for the next print. This is where you may be having trouble. Could it
be that the toner is not being wiped clean? Is there a brush involved that is
spaced too far away from the drum? Is there a broken electrical connection to
a conductive brush?

Since you have cleaned your drum, you may have done some damage to its surface.
However, removal of the photosensitive coating would tend to cause lighter
prints, rather than dirty prints.

Fred

"Jim Adney" wrote in message
...
| I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
| actually have 2 of these and I have been able to determine that the
| "dirt" is caused by the photosensitive drum, by swapping drums between
| printers.
|
| Since I had little to lose, I have tried carefully cleaning the drum
| with alcohol. This had some effect, but not as good as I had hoped.
|
| Is there a better way to clean them? Or are they just totally
| non-servicable?

Sometimes there is a cleaning routine available via the control panel. Or,
you can run a special cleaning sheet through the printer. If it's still bad
you need a new/rebuilt/recoated drum.

N

Jim -

Isn't there a rubber blade of some kind - a squeegee in effect - that is
supposed to clean excess toner off the rotating drum after the image has
been transferred to the paper? If so, check for nicks, wrinkles, lumps,
hard spots, etc. Kind of like the edge of the rubber windshield wiper
on your car, where a small wear spot or defect can have a surprisingly
large effect.

Bill Jeffrey
============================

"jakdedert" wrote:

Yes, and I even have some spares here, but this problem occurs with
few copies (1300) passed thru the copier, and we're not even close to
what the lifetime of the drum should be. The surface of the drum does
not appear to have any damage to it, and I can't see anything on it
that would indicate a problem.

On Mon, 27 Sep 2004 21:52:51 -0500 Jim Adney
wrote:

On Mon, 27 Sep 2004 19:32:57 -0500 "jakdedert"
wrote:

That one, I believe, is meant to be changed out every so many thousand
prints. If you do find a way to resurface it, make sure to empty the used
toner reservoir.

Yes, and I even have some spares here, but this problem occurs with
few copies (1300) passed thru the copier, and we're not even close to
what the lifetime of the drum should be. The surface of the drum does
not appear to have any damage to it, and I can't see anything on it
that would indicate a problem.

Now, let me add a complication: The periodic "dirt" lets me calculate
the diameter of the culprit, assuming that the paper moves along the
rollers without slipping. The calculated diameter is 19mm, while the
drum is 30 mm. There is a 19mm magnetic roller that feeds toner to the
drum, but nothing I do to it seems to have any effect on the dirty
printout.

Correction: The periodic dirt predicted a 30mm source roller and the
drum is 30mm, so this is the source.

The drum LOOKS perfect, no scratches, none of the green photosensitive
surface appears to have been removed by cleaning (no green on the
cleaning wipes.)

I took the drum assy apart this evening and cleaned everything I could
get at. This included the "cleaning blade" which scrapes excess toner
off the drum, and the auger which moves waste toner down to the catch
tank at one end. The corona wire is clean, as is the grid in front of
it.

I finished by wiping off the drum itself with a sterile medical
alcohol prep wipe.

The initial result was an extremely dirty output page, but it's slowly
improving, I assume as the occasional bits of tramp toner get caught
up and carried out of the paper path. It's also possible that the drum
is slowly recovering from exposure to light and that this will just
slowly go away, to some extent.

Nevertheless, it seems to be headed back to exactly the same place
where it started before I did the very thorough cleaning.

One person suggested wiping carefully with a dry silk cloth. What
would be the purpose of this? My guess is that it would serve just to
wipe off the surface without scratching or leaving anything behind.

Now I'm wondering if I should just try soap and water, on the off
chance that the problem is due to oil from the fingers getting on the
drum.

Yes, I realize that this is all a lot of trouble, but it's become a
challenge and I'd really like to get to an understanding of what goes
wrong here.

Thanks for all the suggestions so far.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Sun, 26 Sep 2004 21:18:27 -0500, Jim Adney
wrote:

I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?

thanks,

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------


I was having the same problem with a hp laserjet III. It would work
ok after cleaning, but get dirty within a few pages. Eventually I
gave up on trying to get any of my old toner cartridges working. I
think the rubber cleaning blades had all started to fail from age.
They are designed to have a limited life and not be servicable.
Andy Cuffe

On Sun, 26 Sep 2004 21:18:27 -0500, Jim Adney
wrote:

I have a Panasonic KX-P4400 printer that puts out "dirty" output. I
actually have 2 of these and I have been able to determine that the
"dirt" is caused by the photosensitive drum, by swapping drums between
printers.

Since I had little to lose, I have tried carefully cleaning the drum
with alcohol. This had some effect, but not as good as I had hoped.

Is there a better way to clean them? Or are they just totally
non-servicable?

thanks,

We have one of these that we used once upon a time.(it shelved now as
inkjet got cheaper and more reliable and we got tired of having to
replace print drums and fusion rollers every so often.)
We used to buy from an online source that offered refurbished
drums/rollers at a lower than oem price. Can't remember the url as
it's been four years or so since we last used our kx-p.
They do functionally die after so many thousand prints though.
If you can't google it up give me a shout and I'll dig through our
records and see if I can find the receipts from our supplier.
-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On 28 Sep 2004 11:00:06 GMT (Fred McKenzie) wrote:

As I understand it, the drum is coated with a photo-sensitive material
(selenium) that is electrically charged. It is exposed to an image (laser
light in the case of a printer) that dissipates the charge in relation to the
brightness of the light. In other words, a blank sheet would be completely
discharged.

I've done a lot of web searching and I've picked up a few facts:
Selenium USED to be used, but it's not so common anymore. This drum,
and most modern drums are coated with Organic PhotoConductive (OPC)
material. The OPC material is green.

After the print is made, the drum is wiped clean of toner, recharged, and is
ready for the next print. This is where you may be having trouble. Could it
be that the toner is not being wiped clean? Is there a brush involved that is
spaced too far away from the drum? Is there a broken electrical connection to
a conductive brush?

On this printer, there is a string of 5 LEDs which erases the whole
width of the drum, then a corona wire which recharges it afresh. Since
the "dirt" pattern on the printout repeats EXACTLY, every
circumference of the drum, there must be something wrong with the
surface of the drum in this pattern.

On THIS printer, the image is represented by the grounded area of the
OPC. (Not all printers work this way, but many, including this one,
do.)

Since you have cleaned your drum, you may have done some damage to its surface.
However, removal of the photosensitive coating would tend to cause lighter
prints, rather than dirty prints.

I can't see any visible damage to the drum surface anywhere. There are
a couple of new features to the "dirt" pattern that have started since
I first started this quest, but none of them seem to have anything to
do with my cleaning process. There is one place that looks like the
tip of a thumbprint on the right margin, right where I might have
touched it carelessly at one point.

OTOH, I have scrubbed it with 2 kinds of alcohol and also water in
both linear and helical patterns. Neither of these patterns show up in
the "dirt." Except for the possible fingerprint, the original "dirt"
pattern remains.

Next I'm going to try soap and water (gently) to see if the problem
might be oil or salt from the hands.

It's possible that the OPC material just reacts with something (oil or
salt from my hands...?) in an irreversible way, but that seems
unlikely. There are a couple of web sites out there which even
describe recoating these OPC drums, and even they don't warn you of a
problem like this. They do recommend washing with isopropyl. I may
have to try that.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Wed, 29 Sep 2004 01:10:51 GMT Bill Jeffrey
wrote:

Isn't there a rubber blade of some kind - a squeegee in effect - that is
supposed to clean excess toner off the rotating drum after the image has
been transferred to the paper? If so, check for nicks, wrinkles, lumps,
hard spots, etc.

Yes, it's called the cleaner blade. It's there and it appears to be in
perfect condition. It's just vaguely possible that the drum might be
very subtly out of round such that the drum pulled away from the blade
and didn't get cleaned at the same areas each revolution, but the dirt
patterns look to me to be much too subtle to be explained this way.

Plus, when I had everything apart, I moved the cleaner blade around
quite a bit. I'd think that if it was this close to lifting off the
surface my meddling should have changed the pattern significantly. It
didn't.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On 27 Sep 2004 16:28:01 GMT (Fred McKenzie) wrote:

Check with an office supply store. Some printers and copiers have drums that
are maintenance items, intended to be changed after so many thousand prints.

Yes, I even have some of these here as spares. I'd just like to
understand the problem before I give up and replace it. If I could
look at it and see that it was clearly worn out in some way, that
would be completely different.

My old Xerox XC-830 copier made some lines on copies after having been stored
in a humid environment for several weeks. I carefully cleaned the lines off of
the drum with Kensington "Lint Free Wipes" (plus a little saliva for a stubborn
spot), and it has been making perfect copies for over four years now.

Really? Are you sure this was the photosensitive drum? You actually
touched it with saliva and a finger and it survived without damage?

On these printers there is a magnetic roller that gets all "fuzzed up"
with toner and then brushes up against the drum, feeding toner to the
image portions of the drum. Toner can get clogged up on this magnetic
roller and the standard fix for this is to rub it free with a finger.
This does not appear to harm anything, but this is a different roller.
Still, if oil or sweat from a finger was a problem on the drum you'd
think it would eventually get there from the magnetic roller and
eventually cause a problem.

Of course my copier isn't heavily used. After about six years, it is still on
the second toner cartridge. Even so, the drum is available at the office
supply store for roughly the price of a toner cartridge.

Your usage is about the same as mine. Toner cartridges for this
printer are about $10, but drum assemblies are about $50. Store retail
prices for each are about 50% higher. THIS printer is still on its
FIRST toner cartridge, less than 1400 pages. I just picked this one up
for free, because it was the same model as the one I've had for years.
From the smell, the PO was a heavy smoker. I cleaned a lot of brown
material off the fuser roller, but on the OPC drum there was just a
bit of toner on the ends, which all cleaned off rather easily.

I'm not a smoker, but the printer I've had for years also has a few
"dirt" spots that repeat in exactly the same way. I don't know what I
might have done to cause this, but I'm looking at this as an
opportunity to figure it out, and hopefully find a solution.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Jim Adney wrote:

After the print is made, the drum is wiped clean of toner, recharged, and is
ready for the next print. This is where you may be having trouble. Could it
be that the toner is not being wiped clean? Is there a brush involved that is
spaced too far away from the drum? Is there a broken electrical connection to
a conductive brush?


On this printer, there is a string of 5 LEDs which erases the whole
width of the drum, then a corona wire which recharges it afresh. Since
the "dirt" pattern on the printout repeats EXACTLY, every
circumference of the drum, there must be something wrong with the
surface of the drum in this pattern.

The part of the equation that you are missing is what happens when the drum
sits idle. In that condition, the wiper blade is parked on part of the surface
of the drum with a small pile of toner on its leading side That pile becomes
sort of bonded as all its particles settle into each other. When the drum
starts to rotate as it begins its print cycle, the small pile of toner goes under
the wiper blade and appears as a smudge on the final print.

I have chased this problem on old printer cartridges for years. I have found that
it seems to occur more in cartridges that are used in moist areas, such as
basements and nonairconditioned houses. I first ran into the problem, after
years of never having seen it, when I temporarily moved my office into a
basement. I have never been able to repair a cartridge once this problem occurs,
I have replaced the drums, and wiperblades (with drums and wiperblades from other
cartridges) to no effect. This leads me to think that it isn't a mechanical
problem at all, but rather, a problem with the toner. To that end, I have baked
the cartridges dry, but the problem still remains. So, I think the toner is
permenantly damaged.

-Chuck Harris

Jim Adney wrote:
On 27 Sep 2004 16:28:01 GMT (Fred McKenzie) wrote:


My old Xerox XC-830 copier made some lines on copies after having been stored
in a humid environment for several weeks. I carefully cleaned the lines off of
the drum with Kensington "Lint Free Wipes" (plus a little saliva for a stubborn
spot), and it has been making perfect copies for over four years now.


Really? Are you sure this was the photosensitive drum? You actually
touched it with saliva and a finger and it survived without damage?

I have a manual from an old Mita copier. They recommend repairing a
scratched drum by using automotive rubbing compound. The Mita has a
selenium drum, though.


Of course my copier isn't heavily used.

This is the real problem ^^^^^^^^^^^^^^^

The toner is picking up moisture and mold spores from the air, and
becoming something that nolonger flows freely. The grains of toner
get clumpy. This clumpy toner can ride under the wiperblade when the
drum first starts turning. There, it prints on the paper just like
any other toner would.

There is a reason the cartridges are stored in sealed mylar packages
with silica gel dessicators.

-Chuck Harris

On Thu, 30 Sep 2004 09:12:27 -0400 Chuck Harris
wrote:

The part of the equation that you are missing is what happens when the drum
sits idle. In that condition, the wiper blade is parked on part of the surface
of the drum with a small pile of toner on its leading side That pile becomes
sort of bonded as all its particles settle into each other. When the drum
starts to rotate as it begins its print cycle, the small pile of toner goes under
the wiper blade and appears as a smudge on the final print.

I have to admit that this is interesting, but it doesn't fit my
symptoms. My problem happens on every printout, not just the first
after sitting, and it didn't go away or change when I cleaned out the
waste toner and the drum surface.

The dirt pattern I see is not a simple line and it repeats itself over
and over again down the page and onto consecutive pages. It does not
always start at the same point on the page, as you might expect if it
had something to do with how the toner was sitting there.

It went away when I swapped drum assys (fed by the same toner,) but
that could still be your stagnant toner on top of the drum hypothesis.

I appreciate your suggestion, but I don't think we're there yet.

I haven't had a chance to try the soap & water yet, but I've pretty
much given up on being able to fix this. I'm about to admit that
there's some chemistry that happens between the OPC and something from
the hands that is irreversible.

I'd still like to understand what that is, however.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Thu, 30 Sep 2004 09:22:46 -0400 Chuck Harris
wrote:

The toner is picking up moisture and mold spores from the air, and
becoming something that nolonger flows freely. The grains of toner
get clumpy. This clumpy toner can ride under the wiperblade when the
drum first starts turning. There, it prints on the paper just like
any other toner would.

I can test this as it gets colder outside and our inside humidity
takes a nosedive. It's worth considering. If cold dry weather makes
things better that's a pretty good sign.

However, I think it would be hard to explain why this should produce a
pattern that repeats itself exactly, over and over again, despite any
kind of cleaning and disturbing of the drum.

Yes, when I cleaned out the waste toner chamber above the cleaner
blade there was lots of stuff up there that was stiff and clumped. A
lot of it even seemed to be mixed with something fibrous, but I'm not
sure about that; it was probably just paper dust packed in there. I
felt SURE that cleaning all this out would make SOME difference, but
it didn't....

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

Jim Adney wrote:

The dirt pattern I see is not a simple line and it repeats itself over
and over again down the page and onto consecutive pages. It does not
always start at the same point on the page, as you might expect if it
had something to do with how the toner was sitting there.


If your dirt pattern repeats several times on a page, and doesn't start
at exactly the same spot each time, it is definitely a damaged spot on
your drum. The printer is designed in such a way that where a page starts
on the drum changes each time you print. This keeps ghost patterns from
being "burned" onto the drum.

With selenium drums, you could polish the surface and restore its activity.
This was typically done with a rebranded form of automotive rubbing
compound (with no wax!).

The organic films are quite a bit more delicate... both physically, and
optically. The only reason they were used is because they produce
negative images. This allows the laser to come on only during the black
parts of the page. Kind of important to the short lived early laser diodes.

Since your drum is bad anyway, and this has moved to the purely experimental
stage, give rubbing compound a try. Use a bit of damp chamois, rather
than cloth or paper. Light pressure would be in order.

-Chuck

On Tue, 28 Sep 2004 20:41:55 -0500 Jim Adney
wrote:

Now I'm wondering if I should just try soap and water, on the off
chance that the problem is due to oil from the fingers getting on the
drum.

Okay, I've now tried that and the main thing I can report is that it
didn't hurt anything. It looks as though some of the original dirt
pattern has been lightened, but the pattern along one margin, where it
looks like there might be a thumbprint, does not appear to have
changed.

I washed with Ajax dish detergent diluted with tap water, rinsed with
tap water, then with distilled water, and finally wiped with a 70%
isopropanol-soaked medical prep wipe.

I did this while wearing surgical gloves to assure that I didn't get
any additional contamination from my skin onto the drum. So at least
now I know that detergent, water, and isopropanol don't attack the OPC
coating.

I may try this again, to see if I can get more improvement. I'll have
to try to scrub the right margin area more thoroughly.

This is becoming a terrific time-waster!

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Tue, 28 Sep 2004 20:41:55 -0500 Jim Adney
wrote:

Now I'm wondering if I should just try soap and water, on the off
chance that the problem is due to oil from the fingers getting on the
drum.

Okay, I've now tried that and the main thing I can report is that it
didn't hurt anything. It looks as though some of the original dirt
pattern has been lightened, but the pattern along one margin, where it
looks like there might be a thumbprint, does not appear to have
changed.

I washed with Ajax dish detergent diluted with tap water, rinsed with
tap water, then with distilled water, and finally wiped with a 70%
isopropanol-soaked medical prep wipe.

I did this while wearing surgical gloves to assure that I didn't get
any additional contamination from my skin onto the drum. So at least
now I know that detergent, water, and isopropanol don't attack the OPC
coating.

I may try this again, to see if I can get more improvement. I'll have
to try to scrub the right margin area more thoroughly.

This is becoming a terrific time-waster!

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------


You don't have much to loose....try additional solvents...acetone, MEK
(methy-ethytl-keytone), ethyl alcohol, WD-40 (do this one first), all the
"ozone unfriendly...(hahahahaha)" fluids, etc.

Use Kodak lens tissue to wipe the drum...NEVER any kind of paper tissue (which
is loaded with abrasive material)...or freshly-washed microfiber lens cloth.



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