bad cartridge wiper blade, LJ III

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Tom

Help someone,
my HP laserjet III started giving me pages that have a wide dark band
from top to bottom. it turned out the wiper blade inside the cartridge
wasn't wipping all the way across the drum.
so i openned up the cartridge and checked out the wiper. it looks OK to
the naked eye but i know it's not wiping properly.
anybody know how to clean the wiper and what kind of grease to coat it
with?

thanx, louie
 
Sometimes the wiper becomes slightly distorted from heat or some paper
fibers getting caught between it and the drum. Sometimes the wiper gets
damaged over time, and the edge gets worn down.

I have had problems with wipers on a number of cartridges. I can
usually (with extreme care) take a business card and gently get it
between the drum and the wiper, and then run it gently from one side of
the wiper to the other (the full width). This sometimes will reposition
it, or clean some paper fibers away. Be careful, because if you are
rough about it, you can scratch the drum. Also, the drum is light
sensitive so do not expose it to bright light for any length of time).

There is no grease on the wiper. It uses a bit of the toner powder to
lubricate it. Make sure you only turn the drum in the correct
direction, or you can damage it or the wiper or further distort the wiper.

There are other sources of a dark band down the page, such as dirty
Corona wires, or dirty "windows" near the erase light source. Make sure
the Corona Wires are clean, and any other area where toner might build
up. Also, a scratched or abraded drum can also cause a dark band, and
that can be caused by a distorted wiper, but even if the wiper is
repaired, the dark area my continue to occur due to damage to the drum
from it.

Art
 
Arthur said:
Sometimes the wiper becomes slightly distorted from heat or some paper
fibers getting caught between it and the drum. Sometimes the wiper gets
damaged over time, and the edge gets worn down.
Click to expand...

well i removed the wiper and it looked OK but when i tried printing
again the dark band was still there. there's no visible sign of damage
or excess wear on that part of the drum. no sign of dirt or wear on the
corona wire. i don't think there's any problem with the laser because
the print image is fine, even on the part where the band is. text on the
page is perfectly readable and it looks as though the band is
superinposed over the print image at that part of the page.
what i can't figure out is where the excess toner is comming from in the
first place. the band starts at the top edge of the page and continues
to the bottom edge. how does the excess toner get deposited on the drum
in the first place?
this model does not have a light to erase the drum. first it passes the
wiper, then the corona wire, then the laser, then the
depositor/developer whatever-ya-call-it. where in that process does the
band get deposited on the drum?
i know its not the fuser because i can pull back the shutter and see the
band on the drum.
and the strangest thing of all is that when i pull back the shutter and
turn the drum with my thumb, it comes around spotless every time. so the
wiper must be wiping. but then i closed it up and print again and the
band is there again every time.
i inspected the surface of the drum with a magnifying glass. the only
sign of wear is the minute streaking- that i assume comes with normal
use- that is only visible in reflected light. it is uniform across the
whole length of the drum, with no visible irregularity where the band
is.

this is really a tough one.

Louie
 
and the strangest thing of all is that when i pull back the shutter and
turn the drum with my thumb, it comes around spotless every time. so the
wiper must be wiping. but then i closed it up and print again and the
band is there again every time.
Click to expand...

Your problem can also be caused by a scrap of paper left over from
some Really Bad paper jam getting caught on some Very Strange Place.

With the cartridge *out*, turn the machine first onto on side, then
onto the other -- shaking it lightly in each position.
See if the dark band moves....

(I know... It ain't exactly as light as a LJ 4L.)

HTH
Jonesy
 
I would not have suggested taking the waste toner and placing it in the
cartridge for reuse without cleaning it fully (by sifting it). Waste
toner often has contaminants in it that will cause prioblems with the
magnetic roller/ wiper (not the waste toner wiper, BTW).

Anyway, you need to figure out where the problems are starting in terms
of the toner transfer.

Be careful about using other toners, some have different specs and
polarities, and will produce no print out or even a negative image.

Art

Tom wrote:
 
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