Remanufacturing the Brother HL 6050 Toner Cartridges
(TN-670 in North America, TN-4100 in Europe)
0349
Released in May 2004, the Brother HL-6050 printer
engine is based on a new 25ppm, 1200 DPI laser engine. This is the
latest engine based on the Brother HL-1240 (TN-460) engine. The
TN-670 cartridge is one of the larger cartridges in this series we
have seen to date. Only the HL-7050 (TN-700) is larger. In addition
to the toner being different, the cartridge is built differently as
well. The stated yield on these cartridges is 7500 pages at 5%
coverage. Because of the higher print speed and yield, the cartridge
is built more robustly.
These cartridges also have a gear driven reset lever
that actuates another lever inside the printer. This gear driven
lever must be set correctly for the printer to accept the cartridge
as new. Figures 1 & 2 show the proper reset position of the lever.
Figures 3 shows the reset lever inside the machine
The first section of this article covers the theory
behind these cartridges. If you are already familiar with the
pitfalls of the HL-1240 cartridges, there is nothing new in the
theory here. If you are not however, it would be best to read
through this section. It may save you a few very frustrating hours.
As of the time of this writing, (June 2004) only
three machines have been released using this engine:
HL-6050
HL-6050D
HL-6050DN
Unlike most of the other Brother engines, only one
high yield cartridge has been released to date. The standard, TN-670
(TN-4100 Europe) holds 220g and is rated for 7,500 pages. The drum
unit is new as well, Part # DR-600 (DR-4000 Europe). It will be
covered in a future article.
As with all brother cartridges in this series, these
cartridges routinely leave as much as 90 grams of toner in the
supply chamber, all the while showing toner out and refusing to
print! Shaking the cartridge at this point will only get you another
25-30 pages at the most before the printer shuts down again.
The remaining toner (90g or so!), MUST be completely
removed from the supply chamber before adding new toner. Failure to
do this will cause back grounding. In addition to contaminating the
toner cartridge, this will also contaminate the cleaning section of
the drum cartridge, which in turn will contaminate the toner
cartridge again. A vicious cycle!
The cleaning section of the drum cartridge consists
of a "cleaning brush" and a recovery blade. The cleaning brush has
two opposite charges placed on it during the print cycle. The first
attracts any remaining toner off the drum. The second repels the
toner off the brush back onto the drum where it then transfers back
into the toner cartridge. This is all done in a timing sequence that
does not interfere with the printing process. If the cleaning brush
becomes contaminated with bad toner that will not charge, the brush
will not be able to clean itself, and back grounding will occur. It
seems to be the nature of contaminated toner that it will accept
most of the charge to be cleaned off the drum, but it will not
accept the charge that would allow the brush to clean itself off at
all. A properly working cleaning brush will at any given time have
only a small amount of toner on it. Once contaminated, toner will
accumulate, which will only cause the problems to get worse.
Since the developer roller actually contacts the
drum, some toner is transferred back into the supply of the toner
cartridge. Once you print with a bad toner cartridge, the drum unit
will become contaminated. Even when you change out the toner with a
good properly recycled or new OEM cartridge, the drum unit will
transfer some of the bad toner back into the good toner cartridge,
which will again cause back grounding. Both cartridges will be
contaminated again.
The remaining 90g or so of "toner" in the toner
cartridge is just below the bare minimum that can maintain the
proper charge level. When the change toner light comes on, the toner
will not charge up to the proper level and will cause the back
grounding. As the toner cartridge reaches the end of it's useful
life, the printer senses the low charge level in the toner supply
and will try to keep the charge level up. This constant charging
keeps an almost "empty" cartridge from back grounding. Once the
printer cannot get the remaining toner up to the minimum charge, the
change toner light comes on. The cartridge at this point will still
be printing properly. If you were to take that same cartridge out of
the machine for a few days, and then put it back in the printer with
out doing anything to it, the cartridge will background. This will
happen because the charge level that the printer was trying so hard
to keep up has dissipated out and the materials left can no longer
accept a proper charge.
What does this all mean?
1) Make sure that your cartridge technicians
thoroughly clean out the supply chamber of the toner cartridge.
2) In the event that they forget, and you have a
shading cartridge. The toner must be completely cleaned out again.
(Do not use the toner over!!), and NEW fresh toner MUST be
installed.
3) The drum unit at that point has to be taken apart
and cleaned out with emphasis on the cleaning brush area. This is a
very simple process but very necessary once contaminated.
How to run test pages, as well as common cartridge
problems will be covered at the end of this article.
Figures 1 & 2
show the proper reset position of the lever. Figures 3 shows the
reset lever inside the machine
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Figure 1 |
Figure 2 |
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Figure 3 |
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1) Remove the fill plug from the toner cartridge.
Dump the remaining toner and vacuum/blow out the cartridge. Make
sure that the gear area is clean. Leaving any toner in the teeth of
the gears may cause a tooth to be damaged and cause a clicking
noise. We have found it best to use compressed air to clean them
out, but to also keep one hand over the gears to protect them. See
Figure 4
2) On the NON GEAR side of the developer roller, pry
off the white spring loaded plastic axle. See Figure 5
3) Remove the two screws and two tabs on the
developer roller end plate and pry off. See Figures 6, 7, & 8
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Figure 4 |
Figure 5 |
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Figure 6 |
Figure 7 |
4) On the GEAR SIDE, remove the three screws and
cover plate. See Figure 9
5) Remove the reset lever and gears. Make sure not to
get any toner on them. See Figures 10 & 11
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Figure 8 |
Figure 9 |
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Figure 10 |
Figure 11 |
6) Remove the black axle. See Figure 12
7) Remove the E-Ring, and small gear. See Figure 13
8) On the doctor blade side of the developer roller,
there is another small plate that is located on the end of the
roller and inside the plastic wall of the cartridge. From the
outside of the wall locate a small round hole. Press in the round
tab located inside the hole. While pressing in turn the plate up so
that the plate and roller are free. See Figure's 14 & 15
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Figure 12 |
Figure 13 |
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Figure 14 |
Figure 15 |
9) Remove the developer roller assembly. See Figure
16
10) Vacuum the doctor blade and foam feed roller
clean. We do not recommend that the doctor blade be removed or the
developer roller felt seals be disturbed. Once a new blade is
available, great care will have to be taken not to tear the seals,
causing a leak. The doctor blade can be easily cleaned by blowing
the excess toner off, and wiping down with a lint free cloth. Be
very careful not to leave any lint behind! Do NOT use any chemicals
of this blade. Brother toner is very touchy, and will most probably
react with whatever is used. See Figure 17
11) Inspect the magnetic roller felts. If they are
compressed, (shiny) rough them up with a small screwdriver. See
Figure 18
12) Clean the developer roller. If there is any type
of white or blue coating on the roller, clean it off with a
dedicated Brother developer roller cleaner. Do not use just any
chemical to clean these rollers as it may react with either the
roller sleeve, or the toner. Only a tested dedicated cleaner should
be used. See Figure 19
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Figure 16 |
Figure 17 |
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Figure 18 |
Figure 19 |
13) Re-install the developer roller, inside end plate
first. Turn the inside plate so that it locks in place. See Figure
20
14) Install the developer roller gear, E-ring, and
black axle. See Figure 21
15) Clean the gears, making sure that the fine
toothed gears have no toner on them. This is a good time to also
check the gear shafts to make sure there is enough grease. If the
shafts appear dry, or the grease is contaminated with toner, clean
the shaft and inside of the gear. Replace the grease with white
lithium grease.
16) Install the gears and the reset lever in its
proper position. Make sure all the gears are meshing properly. See
Figure 22
17) Install the gear cover plate, and three screws.
See Figure 23
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Figure 20 |
Figure 21 |
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Figure 22 |
Figure 23 |
18) Make sure that the reset lever is in the proper
position. See Figure 24
19) On the non gear side, install the developer
roller end cap and two screws. Make sure that the tabs lock into
place. See Figure 25
20) Install the spring-loaded white axle. See Figure
26
21) Fill the cartridge with Brother 6050 Black Toner.
See Figure 27
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Figure 24 |
Figure 25 |
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Figure 26 |
Figure 27 |
22) Replace the fill plug. See Figure 28
23) Wipe the cartridge down to remove any remaining
toner dust.
24) Install the protective developer roller cover.
See Figure 29
25) The back handle can be released by removing the
three screws. This seems to be an easier and cheaper way to make
different cartridges for other printer manufacturers. While none
have been released to date (June 2004) with this modification, there
is a good chance that there will be. See Figures 30 & 31
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Figure 28 |
Figure 29 |
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Figure 30 |
Figure 31 |
There are a series of
test pages that can be run from the printer control panel.
With the printer in the
READY state, Press the “+ ARROW” one time until INFORMATION appears on the
display.
Press “ENTER”
Press the “+ ARROW” two
times for the Print Test page
Three times for the Demo
Page,
Four times for the Print
File page,
Or five times for the
Print Font Page.
Press “ENTER” once you
have selected the page you wish to print.
To change the density of the machine, press the “+
ARROW” three times until QUALITY appears on the display.
Press “ENTER”
Press the “+ ARROW” four times for the DENSITY
setting. “0” is the mid factory standard setting. The range is from
+6 for the darkest to -6 for then lightest.
As with many machines these days, the error messages
are in text, and for the most part are self-explanatory.
As some problems can be caused by both the toner
cartridge as well as the drum cartridge, we have listed both here.
“Toner Life End” message does not go away:
Make sure reset gear lever is in the proper position.
Back-grounding: Toner cartridge and Drum cartridge; by far the most common problem with
these cartridges, there are three major common causes.
1) The first is
contaminated toner. If the old toner in the toner cartridge was not
fully cleaned out, a shaded background will result usually over the
entire page. This can also be caused by a contaminated cleaning
brush in the drum cartridge, which is directly related to a bad
toner cartridge. (See cartridge theory at the beginning of this
article).
2) If the developer
roller in the toner cartridge is worn, it will tend to pull too much
toner, and back-grounding will result. This normally happens only on
cartridges that have been recycled a few times. A normal roller will
have a somewhat mottled look, and the texture should be smooth. If
the roller has lines, small cracks, or just doesn’t look right,
don’t use it.
A dirty developer
roller can also cause this. If the roller has a white or bluish
coating, it must be cleaned. Be sure to use only a dedicated Brother
developer roller cleaner. Any other type of cleaner will probably
react with the toner and cause another set of problems.
3) Another
back-grounding issue can result from the toner being used. Not all
aftermarket toners will work together. This is because there is
always a small amount of toner left on the drum cartridge cleaning
brush. Most aftermarket toners will work over the OEM, but not all
will work over another aftermarket toner. If your cartridges work in
house but background out in the field, it can be that the drum unit
has failed, or that another aftermarket toner was used previous to
yours. Check with your vendor to make sure that your toner will work
on top of another (all) aftermarket brand(s).
Clicking:
Toner Cartridge; On the left side of the cartridge there is a series
of gears with fine teeth. While these teeth are not as fine as the
TN-460 teeth, they can still cause an issue. If any toner gets on
these teeth during the cleaning process, and is not cleaned off, the
toner can cause a tooth to break, and clicking will result. We have
found it best to keep one hand over the gear train when blowing the
cartridge out and when filling it, that way the gears stay clean. If
they do get toner on them, clean the gears and the shafts with
alcohol, and lubricate with fine (white lithium) grease. Both the
shafts and teeth need to be lubricated.
Clicking gears can
also result from toner not specifically designed for the TN-6050
being used. If the toner particles are not uniform, the toner will
not flow easily, and the mixing auger inside the toner cartridge can
bind, causing a tooth to break.
Dark Black Vertical Streaks: Drum cartridge; This is normally caused by either a dirty
primary corona wire, or the blue corona wire cleaner is not in its
"home" position on the left side of the cartridge.
Gray Vertical
Streaks:
This is normally caused by a groove in the developer roller. If the
roller has a groove worn in it, it must be either replaced, or
re-surfaced by a company that specializes in this.
Light Print:
Drum cartridge; Can be caused by a dirty or worn Transfer Roller.
These rollers are located inside the cartridge. In our tests, they
should last at least 2-3 cycles.
Black or white
horizontal Lines:
Toner cartridge and Drum cartridge; Black lines normally appear when
there is a build up of toner, White when there is a dead spot, or
contamination of the roller. If the lines repeat every 94 mm
(approx. 3 3/4"), the drum is bad, or dirty. If they appear every
39mm (approx. 1 9/16"), the developer roller in the toner cartridge
is bad or dirty.
Solid Black Pages: Drum cartridge; Bad drum ground contact, probably from the drum axle
shaft to the contact gear inside the drum.
Perfectly straight
thin black lines down the page:
Drum cartridge; Scratched drum.
Black dots that
repeat every 94mm (3 3/4"):
Drum cartridge; Bad drum, or something is stuck to the drum surface.
© 2003-2004 Summit Laser Products, Inc.
Any attempt to reproduce any part of these instructions without the written
consent of Summit Laser Products, Inc is prohibited. All registered trademarks
are the property of their respective owners.
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