Does your laser printer need a service?
It you have used your printer for several years without giving it any maintenance,
you may find this section helpful in reviewing its current condition. If you have recently bought a
second hand printer or a used printer that nas not been fully refurbished by us or another reputable
supplier, you should may wish to assess its general condition and check its maintenance count.
Most heavy-duty laser printers have maintenance intervals ranging from 200,000
to 350,000 pages. A major service requires that the printer be thoroughly
cleaned and a new maintenance kit installed. On a monochrome printer, the kit
usually consists of a fuser, transfer roller and paper pick-up rollers. These
components are subject to wear: the print quality will deteriorate and paper
jams will become more frequent unless they are replaced. Light-duty laser
printers do not usually have a recommended maintenance interval: you are
expected to buy a new one when it breaks down. They also lack an LCD control
panel to provide you with printer messages and inform you when maintenance is due.
The page count at which the last maintenance was performed or the next
maintenance is due is usually recorded in the printer?s memory and it can be
accessed via the LCD control panel. On HP printers, the maintenance count is
also printed out on the configuration menu page. Most heavy-duty printers will
beep and display an error message when the next maintenance falls due. Once the
printer has been serviced and these components have been replaced, the
maintenance count should be reset.
Your printer will give better quality output and vital components will last
longer if the printer is serviced every 50,000 pages or once a year. Such a
service will not normally require that you install a new maintenance kit and it
should not be very expensive. It will enable most problems to be identified and
resolved before it becomes necessary to undertake expensive repairs. All
printers accumulate a lot of paper dust and some waste toner that can be spread
throughout the printer and may coat paper pick-up rollers and fuser rollers.
This leads to more frequent paper jams, greater wear on the fuser rollers and
reduced print quality. Keep the internal parts of the printer clean to maintain its print quality
and enhance the service life of its components.
Paper Jams
An obvious indication that your printer needs a service is an increasing incidence
of paper-feed problems: the printer may not pick up the paper from one or more trays; the printer may
pickup multiple sheets of paper at the same time; or the printer may consistently jam the paper in one
position of the paper path. The first two problems can be addressed by cleaning the pick-up rollers,
the feed/separation rollers and the separation pads in each tray (HP printers). The rubber surfaces
of the pickup rollers should have a fine tread to help them grip the paper: check the rubber surface
has not worn smooth. Check the rubber surfaces of the separation pads to ensure they are not worn:
they should have a uniform, coarse texture to enable them to grip the paper. Look for worn or shinny
spots on the pad. If the printer is not picking up the paper at all, replace the paper pick-up rollers.
If the printer is picking up many sheets of paper at the same time, replace the feed/separation rollers
and/or the separation pads. It is best to replace all rollers and pads as a set.
Clean all other paper feed rollers in the paper path. Remove all grey/white crusted
deposits on the rubber surfaces by scrubbing them with a cotton cloth dipped in methylated spirits,
isopropyl alcohol or similar solvent. A gentle wipe is not sufficient. All the feed rollers should
be a uniform colour (usually grey or black) and have a grippy surface texture. If you continue to
have paper jams as the paper is exiting the printer, you may need to replace the rubber re-drive rollers
or the rubber exit rollers.
If paper jams occur just before, during or just after the paper has passed through
the fuser, you may find that one or more small pieces of paper are jammed in the fuser. You may need
to remove the fuser from the printer to gain sufficient access to remove the paper. On some models,
you will find a pressure release knob that will make it easier for you to remove the paper from between
the fuser rollers. On a typical Lexmark A4 fuser, the rollers are pressed together by two strong springs,
one at each end of the fuser. If you place a wedge under each spring retaining bracket, you can relieve
the pressure on the rollers and this makes it much easier to remove any remnants of torn paper.
Another possible cause of paper jamming in the fuser is that a user may have attempted
to print on a transparency that is not rated for use in laser printers: the transparency melts onto the
fuser rollers and obstructs the path of the paper. Again, a user may have attempted to print on labels
that are not rated for use in laser printers: the glue melts in the fuser and one or more labels may be
stuck onto the fuser rollers and thereby obstruct the path of the paper. You should never use a sheet
of labels from which some labels have been removed. You should always change the paper type setting
on the printer from plain paper to labels or transparencies (as appropriate) before attempting to print
on media such as this. The printer will then adjust its fuser temperature and roller pressures accordingly
to minimise the chances of damage to the printer.
You may need to dismantle the fuser in order to remove all remnants of paper caught inside.
You may find the schematic diagram of an Optra T61X fuser elsewhere in our Support Section to be helpful.
Most Lexmark A4 fusers in commercial quality printers are very similar design. If you can not find any
evidence of paper jammed in the fuser, you should check the condition of the fuser gears: you may find
that one or more fuser gears are worn or some of the teeth on the gears are broken. You may find that
one or more detack claws are missing or dislodged in the detack assembly (see the picture under the T522
fuser components icon in our Support Section. You should also check the condition of the fuser rollers
themselves: you may find ripples or cuts in the surface of the pressure roller that can catch the edge
of the paper as it feeds through the printer; or you may find the remains of a plastic transparency stuck
to the hot roller. You may need to overhaul or replace the fuser.
Print Quality
Another obvious indication that your printer needs a service is a gradual
deterioration in its print quality. Most print quality problems are caused by a
worn, leaking or faulty toner cartridge so replacing the cartridge is always
the first step. Remove the old cartridge. If the printer is a Lexmark, you
should clean the primary charge roller (PCR) as described elsewhere in our Support Section.
The PCR is a brown rubber roller that usually has a light grey coating
of toner: if the coating is carbon black or sooty, the old toner cartridge was
probably leaking. You should vacuum the inside of the printer and clean the
internal paper path with a micro-fibre cloth. Insert a new toner cartridge or
another cartridge that you know is in good condition. If the print quality
problem persists, check the transfer roller and the fuser. A worn transfer
roller will produce light and uneven quality prints; a dirty transfer roller
will produce black marks on the back of every printed page. A worn hot roller
in the fuser will produce unwanted black toner marks of the face of the printed
output.
If your printed pages have recurring marks or lines across the page,
the problem is most likely to be caused by the toner cartridge. A recurring dot or blob
of toner on the page is most likely to be caused by a damaged OPC drum in the cartridge.
You can visually inspect the OPC drum (usually a blue or green coated aluminium roller) and
check for any signs of surface damage. You can identify the origin of the lines or toner
spots by measuring their distance apart on the printed page. You can compare this distance
with the circumference of the various rollers in the printer. For example, in Lexmark S
or T series laser printers, horizontal lines about 90mm apart down the page usually indicate
a damaged OPC drum in the toner cartridge. Similar lines about 20mm apart (especially on
graphics pages) usually indicate a damaged developer roller in the toner cartridge.
In either case, you need to replace the cartridge.
Other print quality problems that are usually caused by a faulty toner
cartridge include very light print that is difficult to read; repeiitive images or shadows
of previous text repeated at intervals down the page; or the breaking up or uneven density of
solid black printed sections eg horizontal bars on configuration pages or demo pages.
If you are really unlucky, very light or uneven prints may be caused by
a failing high tension power supply or a faulty printhead (laser imaging assembly) in your
printer. Sometimes, vertical white lines all the way down the printed page (in areas that
you expect to be black) can be caused by a dirty mirror in the printhead. You can solve this
problem by cleaning the mirror with isopropyl alcohol.
Leaking toner
Another indication that your printer needs a service is a build up of toner and
paper dust in the paper input tray. These trays are usually plastic and can be
cleaned by washing with detergent or wiping with methylated spirits. If toner
reappears soon after the tray has been cleaned, you may have (or have had) a
leaking toner cartridge in the printer. Leaking toner is spread throughout the
printer and often ends up in the paper tray at the bottom of the printer. It is
often more noticeable if the printer has been moved recently and toner has been
shaken down into the paper tray.
If you have a leaking toner cartridge, stop using it immediately and service the
printer to remove excess toner before it leads to expensive repairs. The toner
is spread throughout the printer and may splatter the transfer roller and paper
guides so that the back of your printed pages will be covered with black marks.
The toner may coat the paper pick-up rollers and cause their surfaces to become
slippery and produce frequent paper jams. The toner may enter the fuser and
coat the fuser rollers and the thermistor. Once in the fuser, the toner is
heated and melts. It changes from a fine plastic powder into lumps of hard, jagged
plastic that can damage the rollers and gears in the fuser.
Leaking toner can coat the thermistor and solidify into a hard plastic coating
that insulates the thermistor from the hot roller. The thermistor will no longer read the correct
temperature: this will cause the fuser to overheat and damage its components.
If the fuser is overheating, you will notice a brown discolouration on the cream plastic
cover (fuser wick cover) on the top of the fuser. You will also notice that the hot roller has
turned from brown or grey green in colour to an ocean blue colour. Overheating will cause the plastic
gears in the fuser to become brittle and then disintegrate. The fuser rollers will no longer rotate
and you will have persistent paper jams as the paper enters the fuser at the rear of the printer.
The Fuser
You should periodically check the condition of the fuser even though the page count
may not indicate that it is due for replacement. This is particularly relevant if you have purchased
a used printer or a second hand printer that has not been fully refurbished by us or another reputable
supplier. You will need to dismantle the fuser to clean and inspect it properly but even an external
inspection can help in the identification of possible problems.
If you choose to dismantle the fuser, you should refer to our T61x fuser parts diagram
and our T522 fuser components photographs elsewhere in our Support Section. You should begin by removing all
accumulated paper dust and toner particles from the fuser. Inspect the thermistor to ensure
that its surface is not encrusted with toner and that it is making good contact with the hot roller.
Check that the upper fuser roller is not turning blue as a result of overheating and check that the
teflon coating is not worn off.(Lexmark printers). If the teflon coating is worn off, toner will stick
to the aluminium roller and black marks will appear on your prints. Clean the surfaces of the upper and
lower fuser rollers using a cotton cloth soaked in methylated spirits, isopropyl alcohol or similar
solvent. Inspect the surfaces of both rollers for wear and damage such as scratches on the surface
of the upper roller or cuts or ripples in the surface of the lower (pressure) roller. If the silicon
rubber surface is damaged, the leading edge of the paper passing through the fuser may catch on the
tare or cut or ripple in the surface. The result will be a paper jam. Check the pressure roller is not
deformed (out-of-round) or you will hear thumping noises as the fuser rotates.
You should check the condition of the heating lamp. In Lexmark printers, this is
a halogen lamp about 250mm long. The wattage of the lamp should be stamped on the white ceramic connectors
at one end of the lamp. The wattage ranges from 500 watts in an Optra S 1855 to 875 watts in faster models
such as a T622. Check that the correct lamp is installed to suit your printer. Check that the white connectors
at either end of the lamp are firmly fixed to the glass. You can check the lamp for continuity using a multi-meter.
Look for signs of white cloudy or black coloured deposits on the glass. This is a sign that the lamp filament
is wearing out and that the lamp should be replaced. When you re-assemble the fuser, be careful to ensure
that the ends of the lamp make good contact with the metal connectors holding the incoming wires: otherwise
no current will reach the lamp.
Inspect the condition of all the fuser gears. Check for worn or missing teeth
and for signs that the bakelite material is crumbling. If you have any doubts, replace the gears:
they are not expensive. If the gears fail, the fuser rollers will not rotate and you will have
constant paper jams. Check the ball bearings are not encrusted with toner or turned blue as a
result of over-heating. If the centres of the bearings are blue-black in colour, the grease has
probably melted and leaked out of the bearings: you will need to replace them or they will soon fail or seize.
Check that all the detack claws are in their correct positions and that their contact
surfaces are smooth and not encrusted with toner: otherwise they will scratch the hot roller.
You can clean the surface of the detack claws by scraping them with a razor blade.
If the claws show signs of deterioration, you should replace the detack assembly.
Check the paper path sensors are sitting in their correct positions and operating freely.
There are two such sensors in most Lexmark fusers. One is on the right hand side at the rear of the fuser
and it monitors the progress of the paper as it leaves the fuser. If this sensor is stuck or broken,
the printer will report a 242 paper jam error even though there is no paper caught in the fuser.
The other paper sensor is the "narrow media sensor" and it is located on the left hand side of the fuser,
about one third of the way from the side. The printer assumes that all narrow media passing through the fuser
are envelopes. Since envelopes are thicker than a single sheet of paper, the printer reduces the pressure
of the springs that hold the two fuser rollers against each other. It does this by activating
the "thumper" solenoid in the fuser to pull on the spring mounting brackets and hence reduce
the pressure between the rollers. You will hear some obvious thumping noises as an envelope passes
through the fuser: this is normal and is not a cause for concern. If the narrow media sensor is broken,
the printer will always assume that it is printing envelopes and it will slow down to half speed after
printing a few pages at normal speed.
After you have re-assembled the fuser, you should check its operating temperature
while printing. It should be around 180 degrees Celcius. If the temperature is too low, the toner will
not be well fixed to the paper. If the temperature is too high, many components in the fuser will be damaged.
Some preventative maintenance can save you a lot of money.
