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Copyright © 1994-2008
Reproduction of this document in whole or in part is permitted if both of the
following conditions are satisfied:
1. This notice is included in its entirety at the beginning.
Note that many of the problems and solutions are listed with respect to
specific models. Even though your model and problem may not be included,
there is a good chance your problem is covered but with respect to some other
model printer or copier. Therefore, search for a generic description of the
symptoms and you may get lucky.
Since the operation of laser printers and photocopiers is very similar, check
both chapters to see if your problem is covered when dealing with either type
equipment.
There is also a chapter on fax machine problems though it is pretty sparse
at the moment.
Eventually, this document may be expanded into a full "Notes on the
Troubleshooting and Repair of Printers and Photocopiers". For now,
be happy that it exists at all! :-)
As always, comments, suggestions, and corrections are welcome.
Portions of this document also appear at PrinterCartridgesInk.com
under "Printer Advice". As far as I know, this was done without my permission but
since he included the appropriate attribution and copyright notices, I'm not
complaining. The formatting may even be a bit better. :)
See the document: Troubleshooting and Repair of Consumer
Electronics Equipment for general information on tools, test equipment,
tips, techniques, and much more.
While printers are not generally considered dangerous pieces of equipment
(compared to TV, monitors, and microwave ovens, at least), some types - laser
printers in particular - present a variety of hazards that should not be
underestimated. In addition, photocopiers - particularly larger high speed
machines - need to be treated with great respect while servicing.
There are minimal dangers in servicing most printers. However, there may
be exposed line voltage near the line cord and long hair or neck-ties may
be sucked in along with paper! Laser printers have their lasers but these
are generally located such that accidental exposure to the beam is minimized.
The toner in copiers, plain paper faxes, and laser printers may be harmful
if inhaled and is a potential fire/explosion risk if carelessly vacuumed.
Each of these possible safety issues is discussed below with additional
specific information in the chapters for the equipment to which it applies.
All in all, working on printers is relatively low risk.
The first set of items applies to all line operated printers:
The following apply to laser printers and photocopiers:
And finally, for laser printers and laser photocopiers:
Fortunately, under normal conditions, the laser beam will not be turned on
unless all interlocks are closed and a page is actually being printed and/or
will be in constant motion as a result of the scanning mirror (which reduces
the risk considerably). (It is virtually impossible to get to the laser
beam before the scanning mirror without total disassembly.) However,
certain failure modes could result in a stationary beam which ignores the
interlocks so take care whenever working on a laser printer with the covers
removed.
For text, an internal character generator (ROM) converts ASCII codes to
pin firing patterns. For arbitrary graphics, the actual bit map is read
out and used to control the pin drive.
The paper, carriage, and sometimes ribbon movement use stepper motors. These,
their drivers, or interconnect cables, are common problem areas.
Instead of pins, these use a wheel with all the possible characters molded
on 'leaves' around the perimeter. The wheel spins to the correct character
position and a hammer than taps the leaf to impress the character (via a
ribbon) on the paper. Carriage and printhead movement is similar to that
of dot matrix printers.
(From: Peter (hedgieus@yahoo.com).)
Some history/trivia:
The daisy wheel printer (interestingly) was patented before World War II!
It was GE or a GE engineer, but only commercialized by Diablo, which was
later bought by Xerox in its expansion to California. Later spinoff was
Qume, and then lot of companies got into it, some Japanese, some local
(California). Daisy wheel technology was killed by the laser printer
becoming cheap and having better quality. Original impetus for it was
speed: IBM Selectric was able to print at 10 char/s (good for 110 baud
modems!). It moved the whole ball (big inertia). Daisy wheel only moves one
spoke, (to print one character) and got 30 chars/s.
Near the end of the era, 'on the fly' printers got as fast as 80 char/sec.
There is a US publication called 'The Hard Copy OBSERVER' from Lyra
Research Inc. Tel: (617) 322-0708.
This discusses the latest technologies and who does what. It may not
cover the print head technology very much but is a good read if you are
into print technology in general.
There are many companies that sell variable print processes. One I have
heard of is RALFLATAC. They do a brochure that does an excellent brief
of most technologies available for printing. They have UK (and many
other sites in europe) and US sites. UK Tel 01732-583661, US Tel (704)
684-3931.
I have no idea if you can easily get copies of either publication from
them so here goes a very very brief description.
Ink jet printing has two main types, continuous ink jet (CIJ) and
impulse printing (DOD) (drop on demand). Each of these can be a single
jet, or an array of jets.
CIJ is a continuous jet of ink cycling round a system and occasionally
(when required) a drop is deflected out of the stream onto the paper.
The stream is modulated to break it into a consistent drop size. The
deflection works like the beam on an oscilloscope. If you charge 1 drop
and pass it between two high voltage plates it is deflected. This
system also requires cunning mechanics, but the support electronics is
much more complex, and probably one of the reasons for its performance
limitations being not up to what you might expect. The calculations of
the aerodynamics of drops being deflected is no small task, even if look
up tables are used.
DOD works in principal like an old Dot Matrix pin printer. Instead of
firing a pin at a ribbon, a drop of ink is fired at the paper. The drop
is fired by either a piezo crystal squeezing the ink out of a small tube,
or by boiling the ink and the vapor forces the ink out of the chamber.
The key to both of these processes is in the mechanical design of very
small components if 300 dpi is required. The control electronics is a
bit cunning, but I figure it is the easy bit.
Priming and cleaning are normally done automatically upon power-on and
possibly between pages. However, additional cycles may be needed at times.
With the water based ink, even if the printer is powered off properly which
seats the cartridge(s) on a rubber seal, some evaporation occurs so priming
will often be needed after it sits idle for a while. Note: Don't kill power
to an ink-jet printer as soon as your printout pops free - it needs to
position the printhead and cartridge(s) on the rubber boots. Wait until the
printhead stops moving and clunking. Some (older) printers don't even have a
seal in which case letting it sit idle is even more likely to result in
problems.
If there has been ink spilled into the priming area, it may clog up the
little hose connecting the priming station to the pump - I have used a wooden
toothpick to clear the hole though this may be risky if it should break off.
With care, a wire rounded off at the end so as not to puncture the tubing can
also be used. Complete disassembly and washing of the parts is probably the
best but is probably a pain.
The original ink jet printer of this type was the Teletype Inktronic,
which introduced the concept of video-type distortions to printing.
It appeared around 1970, and was so bad nobody tried again for years.
(From: Tony Hardman (AHED_CIJ@f54x19.demon.co.uk).)
I guess that is why it was used in industrial applications I guess.
Were the 'video-type distortions' a deliberate feature or just a
coincidence of how they turned out?
Who are/were Inktronic???(apologies to anyone connected with them) I
guess that may have been spin off development from some work contracted
out by IBM, but it was so....?? (costly/low res/unreliable - choose
one) they lost interest. Although one of the very early machines still
runs well on a textile mill. It had a large number of jets side by
side, and may be multi color too. I've only seen the patents so don't
know exactly what it looks like.
I thought original ink jet printer was a chart recorder developed in the
last century. It was just a nozzle on deflection mechanism, and was not
modulated so it was always printing. It was a lighter mechanism than
actually trying to move a pen and so had some performance advantages over
other technology available at the time...
The same reason CIJ still sells world wide, even when high resolution
DOD is biting at its heals.
Here are history/trivia. (I used to work at Xerox marking technology group,
working on ink-jets and daisy printers.)
Type 1 was commercialized first for printing postal labels and other similar
applications. It was a big machine - 5x5x5 meters! Clumsy but fast. This
was before laser printers. IBM published detailed (and definitive) research
paper on this - circa 1985.
(From: John Eaton (johne@vcd.hp.com).)
The trick is that a lot of the energy that you pump into the resistor
leaves the printhead with the fired dot. One way to detect Out_of_Ink
is to mount a thermistor on the printhead and watch for a sudden rise
in temperature as you are firing.
Like most print processes you only have a limited selection of inks to use.
Full colour can be derived from three primary colors, just like a monitor.
For monitors, these are Red, Green, and Blue because monitors emit light
resulting in an additive color process. Inks, on the other hand, absorb
light so printing is a subtractive process. The resulting inks should then
be cyan (blue+green or -red), magenta (red+blue or -green), and yellow
(red+green or -blue).
Therefore, the colors used in common ink-jet printers are not really capable
of producing true full spectrum photorealistic quality results since they are
red (not magenta), blue (not cyan), and yellow. These are optimized for nice
saturated primary colors when used independently. Also see the section:
Why are red, blue, and yellow inkjet primaries?.
In addition, the combination of the three primary colors should be capable of
being combined to produce black but due to misregistration and the pigments
used, this black would be somewhat muddy and brown. Therefore, a separate
black ink cartridge is normally used for black printing.
(From: Tony Hardman (AHED_CIJ@f54x19.demon.co.uk).)
With printing there are more problems than solutions and I do not know
which method HP use in their printing.
If you can vary the drop size, you can change the drop spread on the
paper. This can be done by firing bigger slugs of ink, or multiples of
the drop at the same position. As you can figure the ink will either
spread and make a bigger drop, or stay the same size and become denser.
Depending on the resolution you want these could both improve colour
density. This depends on two key components.. The ink, and the paper.
The problems with laying down multiple drops on paper is that if you do
a large block the paper will curl up and the overall image becomes
worse. This is why you can pay 1$ a sheet for 'quality' paper.
Another problem with this is speed. Firing two drops in the exact same
place is difficult... Unless the head is stationary but that is not good
either. You may notice that most DOD printers in high resolution mode
do a number of passes over the same place. This does allow dithering
and other techniques for resolution / colour enhancement. They usually
only print while going in one direction for improved mechanical control.
In the 1600 printer there is a heater to assist with the drying times
and reduce the curling problem.
Inks are a problem too. They can dry at different times because of the
different dyes used, or they may not mix how you expect if you place two
colours on top of each other. Its only ink ... but to get the best
balance of surface tension, drying time, viscosity, colour,
stability.... and more is not as straight forward as it might seam. I
have noticed that the water based inks are improving, and there are some
that do not run if they get wet (after drying on the paper).
I think the spec in your manual may suggest what method they use..
The printer resolution (best) is 600dpi (I guess), and I recon the best
full colour resolution is lower. Also the print head is only 300dpi so
you must do two passes to get 600dpi black (single black ink cartridge).
This suggests a partial step of 1/600 inch between the passes.
What happens when you print black using the colour head? How many
passes, how much slower? The resolutions quoted may also be 600 * 300,
or what ever. If they make blocks of colour from a potential 600dpi
machine, the resultant image is probably only 75dpi (possibly less).
This still might be called 600dpi, because the drop placement uses this
resolution, but it is not 600dpi at full colour. The resolution of
quality picturers / poster is several thousand dpi, but not a variable
image (not ink jet).
In the Lyra publications they did publish the real print head
specifications for the machines they review. They also include some of
the methods of colour printing.
After all this I have noticed that I have not answered the question of
how do HP et all get their colour resolutions. All I have mentioned is
a few of the parameters that the designers have to deal with.
I don't know the precise answer but it is no doubt a tradeoff between cost
and which colors are used most often. For non-photo printing, the straight
red, blue, and yellow are far more useful since they can be use by themselves
or in simple combination to produce a wide range of vibrant, if not realistic
colors. For example, pure red is far more likely to be used for simple
graphics than magenta. To make something that looks like pure red using
magenta and yellow requires a precise combination - not easy to do with an
inkjet printer!
(The following is from someone who also sells inkjet refill kits so this
may not be an entirely unbiased writeup.)
(From: John Connolly (toner@idirect.com).)
There are at least 10 ingredients in inkjet ink, starting with triple
distilled, de-ionized water, dye or pigment color of a known particle size,
humectants such as glycol to minimize evaporation (and head clogging),
surfactants to balance the surface tension and paper wetting, resins to get
good paper adhesion, biocides and fungicides and buffering agents for the
correct pH. These considerations ensure that properly reverse engineered
inks not only work, but produce a print comparable to the OEM. For printers
like Epson, with fixed permanent print heads in the printer, expensive
repairs are also avoided.
To make matters worse HP has rigged their most popular black cartridges for
the Deskjet 500 & 600 series to curb refilling, with air bladders,
constantly changing maze/ venting assemblies at the bottom, and logic to
change the signals to the micro-resistor jets on the 3rd or subsequent
reinstallation of the cartridge. The color cartridges for these MUST be
refilled before air locks occur, particularly in the yellow chamber.
Some people still manage to get an acceptable refilling success rate with
these Deskjets, but we feel it is a bad introduction to refilling for the
first time refiller. Deskjet series 700, 800 & 900 are better bets to
refill.
But, the current Lexmark, Canon, Xerox and Epson cartridges are by far the
easiest to refill.
Image Control's refill kits for the Canon 4000 series refill the BCI-21
black 40 times, or the BCI-21, 12 times EACH color.
More details on inkjet inks, a description of our refill kits which are
larger than most offered, references and printer/cartridge tips are
available at Image Control's Web
Site.
The digital image is generated from a bit map stored in the printer's
memory and modulates the laser beam. Scanning is mechanical - a high
speed motor spins a multifaceted deflection mirror to get the X-axis
and the paper moves to get the Y axis.
LED printers use a large array of LEDs as the image source but are otherwise
similar to laser printers.
Plain paper fax machines use similar techniques in their printing
mechanism.
Beyond this, copiers and laser printers are nearly identical (at least in
principle) except that copiers use a positive process (dark areas in the
original result in marks on the paper) and laser printers commonly use a
negative process (a spot of light results in a dark mark on the paper).
The most sophisticated machines are now actually scanner-laser printer
combinations with buffer memory so that multiple copies can be made without
rescanning the original, sorting and collating is more flexible, scaling and
rotation can be done digitally, and other features not possible with simple
copiers.
(Portions from: Copenhagen Cowboy (cowboy@fastlane.net).)
The photosensitive drum is the heart of the laser printer or copier. In
larger machines, it may be a separately replaceable unit. In most laser
printers and smaller copiers, it is part of the 'toner cartridge' and
is a throw-away (or may be recycled).
The drum is coated with a photosensitive material which has an extremely
high resistance when in darkness. It's resistance drops to a low value
when illuminated.
All of the following takes place as a continuous process as the drum rotates.
Note that the actual photosensitive drum in most copiers and laser printers
has a circumference that is much smaller than the length of the printed page.
Therefore, only a portion fits at any given time and the charging, exposure,
transfer to the paper, cleaning, and erasing is a continuous process:
Where the light hits the drum's surface, its resistance drops dramatically
and the charge in these areas is dissipated.
At this point, a swath of the image of your ultimate copied or printed page
resides as areas of electrostatic charge on the drum. This is a 'latent'
image and must be 'developed'.
Depending on design, the developer material may be separate or actually
combined with the toner.
A magnet in the developer unit which is as long as the page is wide causes
the developer along with trapped toner to stand out following its lines of
force off of its long N-S pole pieces. This forms a kind of brush of toner
and developer material which is in contact with the drum as it rotates with
its latent image. Normally, the developer material brush is C-shaped, and
toner particles are carried in the C-shape (the back of the 'C' is against
the drum).
Here is where the developing processes of copiers and laser printers differ:
Below the paper is another corona, the 'transfer corona'. Another high
voltage is applied to the back of the paper (once again, around 7 or 8
kV DC) to draw the toner from the drum to the paper. (Remember, all this
is going on in a continual cycle and it is all in motion).
That is the basic process. Many variations are possible and depending upon
the machine and manufacturer, some of this may be a little different. Where
a (disposable) toner cartridge is used, many of these components are replaced
with the cartridge - typically the drum, toner itself and developer (usually
combined into a single powder), developer magnet (really neat!), cleaning
blades, some of the corona wires.
There is also some photocopier information at:
In general the principle of electrostatic laser printing is as follows:
The laser steering engine is combined of the following components:
If you need to scan or to print in high resolution 500 dpi or higher, you
end up using a glass F-Theta lens.
(From: David Kuhajda (dkuhajda@locl.net).)
Whatever you do, do NOT use alcohol on an organically based drum, it will
ruin it. The alcohol causes the material to crystalize. I use to do copier
service and this was stressed a lot by the manufacture as they switched from
the old selenium drums to the new opc drums.
Direct sunlight will immediately destroy the drum. A couple of minutes
under normal lighting is no problem, just place it in a dark area and put a
black cloth over the top of the drum while it is out. If you are replacing
the drum cleaning blade or cleaning the crud off the blade, make sure you
powder up the drum completely and the blade before reapplying power. The
toner actually is a slight lubricant and the rubber cleaning blade directly
on the drum will also ruin it. Just print a few low text copies after
reassembling to allow the blade to reseat properly.
(From: hapticz@email.msn.com.)
Short periods (less than 5 min) under fluorescent lighting is safe.
Direct sunlight kills them immediately.
Just have a clean brown paper bag to shove it into while it sits on the table
outside the machine.
Often more damage is done to them physically during insertion/removal. just be
careful.
Xerox used to clean the 10" diameter drums with 90% isopropyl alcohol and some
kind of "Kim Wipes" in our office, that was years ago though.
Get the book: "Easy Laser Printer Maintenance and Repair by Stephen J.
Bigelow".
Your local library should have it or be able to get it. Stephen J. Bigelow
has several other books on printer repair, both laser and non laser types.
All are very good.
(From: Jonathan M. Elson (jmelson@artsci.wustl.edu).)
There is a heater inside the fuser roller. This is what melts the toner into
the paper. It is thermostatically controlled, and then has a safety
thermostat in case the control fails.
There are two photodetectors for the laser. One compensates for dimming
of the laser over years of use, the other picks up the beam at a particular
angle of the polygon mirror, and synchronizes the raster electronics to
the polygon rotation.
The laser is the aperture. With an optical path of 0.5 m or so, the laser
is a pretty good approximation of a true point source. A simple lens makes
it look like a very good point source.
I think they mold these lenses to near correct shape, then grind and polish
to the desired aspheric shape with specialty machines for that purpose.
(Note that almost all eyeglasses are aspheric for astigmatism correction.)
Yes, these lenses are glass, I've had a few printers apart myself.
There are two basic kinds of toner: magnetic and non-magnetic. If your laser
printer has a Cannon 'engine' it most likely uses magnetic. NEVER use the
wrong type. The imaging process is extremely delicate and specific toners are
important. Use of toner that is slightly different could result in all black
or all white copies.
(From: Lionel Wagner (ck508@FreeNet.Carleton.CA).)
If your copier uses non-magnetic toner, it is mixed with iron powder,
called the Developer. Both have to be removed and all residue vacuumed out.
If the copier uses magnetic toner, less of it will remain in the machine.
Try to get as much as possible out. Do not scratch the roller on which
the toner sits.
WARNING: See the section: Warnings about vacuuming
laser printer toner before using a household vacuum cleaner to do this!
(From: Filip M. Gieszczykiewicz (filipg@repairfaq.org).)
Greetings. A few:
BTW, move the carriage all the way to the right, close the cover and
turn it on - does the print head move or does it just sit there and beep?
More depends on the answers and results of the above. BTW, most newer
dot-patrix printers just need 2 screws to be removed to release the
head. I know the Epson LQ-1050 works like that (and many of that Stars
as well). Anyones needs parts from the former? I have one with a dead
head (and it's not economical to repair).
(From: Chris Serrano (brace@loop.com).)
I resurrected one by hanging it pins downs in an ultrasonic cleaner.
A lot of old dried up ink floated right out and the stuck pin became
obedient again.
(From: Filip M. Gieszczykiewicz (filipg@repairfaq.org).)
Greetings. If one does not have the use of an ultrasonic cleaner,
I have found a different way to get these suckers working again.
Go to your local plumbing store and look in the chemicals department
for 'CPVC-PVC-ABS CLEANER' (used to clean plastic pipes). This stuff is
a combination of groovy chemicals Methyl Ethyl Ketone and Acetone.
It will 'melt' most plastics so be sure the print-head's any
plastic parts are safely taken off.
Pour some of this stuff into a GLASS container and put the print head,
business-end first, in it and leave it there for a few minutes. When
the stuff turns dark-purple (all the ink and goo from the print head)
you are done. Let it dry (few minutes) and then oil it with LIGHT
OIL. Note: Do NOT use WD40 - we're interested with something that
sticks around for a few months... WD40 just leaves a 'protective
layer' with almost zilch lubricating properties (it's a Water
Displacer (WD), after all).
I have done this for a few DataSouth DS-180, Infoscribe 1000s,
and Xerox [monster] printers that see a box of 132 column paper
a month (each) for a number of years with excellent results.
Note: YMMV... these printers have rugged print heads (7/9 pin)...
I don't know how a 24-pin Made-in-China feather will respond.
(From: Ralph Wade Phillips (ralphp@gcstation.net).)
What's common in some older Okidata 32x's and 39x's is that the lithium
battery *above* the stepper driver will spring a leak, and drop the lithium
compound onto the legs of the stepper. I do not know for sure if it's
corrosive, conductive, or just plain nasty, but it kills the stepper
deader'n'snot.
I'd LOVE to find a replacement - I've got a service customer that has about
2,500(!!!) 320's and 321's in the field, and I am not looking forward to
having to exchange all those boards over the next several years.
(From: Tony Duell (ard@p850ug1.demon.co.uk).)
I'm going to guess (based on what I've seen in other printers) that
there's a set of power transistors (either H-bridge drivers or 1 per
coil, depending on the motor) that drive the stepper. These transistors
are driven from the printer's microcontroller via an output port - in
this case the '273.
Now, if a TTL chips is getting very hot, then either something is drawing
too much current from it, or something is overvoltaging one of the pins.
A particularly unpleasant failure mode is when a PNP power transistor,
with the emitter tied to the V++ rail (the 20V + rail that supplies the
motors) decides to short and apply said voltage to the output of whatever
device is driving it. If you're unlucky, the next stage is that the
output port device breaks down as well, and the CPU data bus gets 20V or
more on it. The result is blown chips all over the printer. Please don't
ask how I found that out ;-)
My guess is that there's at least one shorted transistor in the stepper
motor drive circuit. If the system uses an H-bridge driver (an equal
number of NPN and PNP transistors) then if one transistor shorts, its
companion is connected across the power rails. When it turns on, the
supply is effectively shorted.
I think you'll have to trace out the driver circuit for the stepper
motor. Figure out what drives what. Test the transistors, and then
replace the defective ones _and_ that '273, which is probably now blown.
Can you determine if it is a mechanical or electronic problem? For example,
with the ribbon removed, does the gear or post that drives it appear to
try to turn or not at all?
Modern electronic typewriters are a combination of keyboard, microprocessor,
and printer. Therefore, the same sort of troubleshooting approachs can be
used as for computer printers.
Common electronic problems include bad connections to the motor that advances
the ribbon (cold solder joints, cracks in traces on flex cable to carriage),
bad motor driver chip, or bad motor.
Mechanical problems include stripped or broken gears, misalignment preventing
advance mechanism from engaging, and defective ribbon cartridge.
(From: Roger D. Waddell (rwaddell@peachnet.campus.mci.net).)
This problem is usually caused by a broken 'E' clip on the bottom of the print
hammer solenoid. The clip holds on a lever that works in conjunction with the
ribbon/correction feed solenoid near the right front of the print carrier.
When the clip breaks, the lever falls out of position and never trips the lever
that assists in feeding the ribbon.
I have seen this problem many times!!
(From: Chris Jardine (cjardine@wctc.net).)
I would suggest that you might have a problem with the ribbon mask. A few
years ago I was the service manager at an Apple dealership. I can't tell you
how many ribbon masks I replaced for many different problems, including wierd
noises. It could also be a problem with the carriage drive motor. I can't
remember which side of the printer it is on, but, it is below the gear/pulley
that drives the toothed belt. You might try some very fine (maybe silicone)
oil there and you might want to clean and then re-oil the carriage guide bar
(the shiny round bar) and the bushings on the carriage that ride on the bar.
The only other possibility would be a problem in the gears below the ribbon
that are responsible for driving the ribbon.
Try powering on while holding escape, this will put you into
service mode. Press the up arrow to start the engine test, if
this works you may have a problem with the xerox controller
board.
Try disconnecting all the n/w cables and reseating the cables
on the system board. Remove this by the two thumbscrews at the
back and slide out as far as you can then pull the cable off.
I have a Compaq Pagemarq 15/20 service manual that I am
selling, but I am in the UK, where are you?
When power is applied, the head appears to try and move, but will not
unless you manually get it started. Then it goes to its home position.
You then hear three beeps, and nothing else can be done to elicit any
response from the printer. The power LED comes on, but the paper-out
will not, regardless if there is paper installed or not. The paper
detect switch is working properly (checked with ohmmeter by
inserting/removing paper while across switch). Also, I hooked up a
resistor and +5 V to the paper-out LED, and it lit up ok. I have also
mapped out the stepper motor leads, and resistance checks show that it
appears to be ok.
MY question is if perhaps I lost one of the outputs for one of the
stepper phases. The controller seems to be one large power-ic from what
I've traced out."
Could be. Do you have a scope? You could check the phases.
Also check for bad connections to the stepper from the logic board - I
have seen these on printers.
It doesn't explain your other problems, however. Once initialized, even
though the print head doesn't move properly, I would expect the printer
to work in other respects.
(From: Joe Wagg (jwagg@fs.cei.net).)
The 3 beeps tell you there's a carriage error, probably from an incorrect
number of steps needed to reach the home position. Since you've already
checked the motor, the next step is to check the motor drivers. Using a
meter with a diode check function, put the red lead on ground and the black
lead on each phase coming from the board (disconnect the motor first). The
readings should be within 20 percent of each other, not open or shorted. Also
make sure the motor, pulleys, and carriage are all relatively clean and move
freely. The other symptoms are caused by the carriage error, which halts the
cpu to prevent damage. Clear up the carriage error and the other problems
should go away. You should also make sure that all socketed chips are properly
seated and don't have dirty contacts.
(From: Asimov (Asimov@juxta.mn.pubnix.net).)
Remove everything that is normally accessible. Then flip the printer on its
back and play a vigorous drum roll all over it. This should dislodge a huge
amount of "holes". Didn't you always wonder where those perforations went?
Well, some of them make it into clogging up under the platten.
Flip the printer on its side and with a thin brush dust the remaining grime
away. If the jam didn't clear up you might try manually inserting a stiffer
paper (postcard, greeting card, etc) a few times before dismantling the
platen assembly any further.
Also check for bad connections. If the printhead motor is a servo (DC instead
of stepper), you have an intermittent feedback problem, again could be bad
connections or bad parts.
(From: Ralph Wade Phillips (ralphp@gcstation.net).)
First off, have you changed the RIBBON? Second, clean the print
head carriage rails. They need a VERY LIGHT coat of VERY LIGHT oil, then
wiped clean.
Usually, when I see this, either the printer is just plain wore
out, or the ribbon is snagging. Since the ProPrinter family drive the
ribbon off of the carriage drive, if it ever snags, you'll get these
symptoms.
(From: Paul Weber (webpa@aol.com).)
Look at the old ribbon. Does it have a short piece of transparent tape at
the end of the ribbon? If so, the printer probably has an optical
end-of-ribbon sensor; a LED/phototransistor pair that looks through the
ribbon. Does it have a short patch of aluminum foil tape (probably on the
back side of the ribbon) ? If so, there is probably a pair of contact
fingers that rub the back of the ribbon as it feeds. Look for bent
contacts or debris in the ribbon holder mechanism.
Look at the ribbon holder mechanism in the printer. Is there switch or
contact pair that could sense the motion of the ribbon cartridge's feed
reel? If so, check for free movement and cleanliness. Does the ribbon
holder move with the printhead on this machine? If so, check that the
ribbon cable connecting the carriage with the remainder isn't damaged and
is connected properly at both ends.
(From: Glenn Allen (pclogic@xtra.co.nz).)
These printers generally need just a clean out and put back together.
I would try to reseat the main logic board first, also try cleaning the edge
connectors. There is a plastic joining bracket between the print head cable
and the main logic board.
If you are getting bad carriage movement then check that the carriage can move
freely back and forth, also check the black teethed guide lying on the bottom
for clogged teeth. The print head ribbon can be removed for better testing.
if the carriage doesn't move freely then you may need to adjust it's position
by loosening the two screws on either side of the print head carriage and then
adjusting back and forth until good movement is achieved.
You are complaining? :-) Usually, it is the other way around!
(From: Ralph Wade Phillips (ralphp@gcstation.net).)
Eh? On the SD-15, the FF SelfTest is for checking HEAD MOVEMENT only. It
sounds like it passes just fine!
Try holding down LINEFEED button instead. :-)
Hewlett Packard has on-line information and documentation at:
The PaintJet printers are 180 DPI and the DeskJet printers are 300 DPI. The
resolution of the PaintJet is about that of a poor 24 pin printer. The
PaintJet and ThinkJet printers are also PCL, so you can use a HP laser
printer driver set to 150 DPI.
There seem to be currently four levels of HP ink-jet printers:
(From: Paul Grohe (grohe@galaxy.nsc.com).)
I've dealt with a few of these buggers before! ;^)
Is yours a DeskJet, DeskJet Plus, or any of the DeskJet 500 or 600 series?
If not, then ...well....then I may as well tell you this anyways because you
will probably run into these some day....(some of the below can apply to other
ink-jet printers).
Try holding down 'FF' during power-up, you may get a different test page.
One of the pages should have a jet-test pattern (A slanted diagonal line
separated by 11 vertical marker lines and little jet ID numbers).
The first page of the standard self test results in that pattern.
I first tried the cartridge that looks exactly the same as the one that came
with the printer (though the part number is different). Then, I tried
another somewhat larger one that apparently has identical connections.
The different part numbers are the 'standard capacity' and the 'high capacity'
cartridges. They're interchangeable.
I assume you have cleaned the contacts (with a Q-tip, on both cartridge and
socket). Use a magnifying glass and check *each* of the gold 'bump' contacts.
Repeated cartridge swapping, or improper insertion, can cause a crack to form
around the base of the 'bump' and the pad (or the pad and the trace). The
'bumps' can also be 'flattened' by cartridges that were forced in at too
much of an angle. There should also be some 'give' or 'sponginess' to the
contact area to assure even contact with the cartridge.
Check for broken/bad traces in the flex-cable that goes from the driver board
to the cartridge. Ohm out the cable between the supply commons and the
individual driver lines (at the PCB) with the cartridge in place. I think
the jet resistance was about 50 ohms (It's been a while). There were four
separate jet sections (commons). All four commons were tied to the +20V
supply through four separate (12 ohm?) series current limiting resistors.
The driver outputs seemed to be grounded emitter, open collector (w/clamp
diode?). The jets themselves are driven individually and are not multiplexed.
To test, I printed an all-black page (with an empty, but installed cartridge)
and watched for activity on each of the lines at the PCB end. Good pulses are
'bi-levelish'. Normally negative going 20V, with pulses down around 15 V, and
going all the way near ground for that particular jet. The commons 'bounce'
because of the shared series current limiting resistor, causing the numerous
smaller pulses around 15 V (caused by the firing of other jets sharing that
common). A bad connection will show up as a weak or distorted pulse. An open
or broken line will show up as 0 V. I theorize that a bad driver would show
just the smaller 'line bounce' 15 V pulses and a shorted driver would show 'GND'
(and also would blow out that jet!).
The current involved to drive the 'jets' is a pulse of short duration and
pretty high current. Any poor connections will cause excessive I/R drop and
the jet may not fire hard enough. A sign of this is drops (dribbles) of ink
that form on the head during printing.
While you are in there, check and clean the rectangular rubber seat that
the cartridge rests on in the 'parked' position. Dry ink can cake up on it,
causing a faulty seal and resulting in dried-up cartridges ($$$!). The rubber
seat pulls off and is easily cleaned with a wet paper towel (wear gloves, or
you will suffer the dreaded 'black finger syndrome'). Also clean the 'nose
wiper' that sticks up about a centimeter to the left of the cartridge seat.
This always cakes up and can cause printing problems.
To manually prime an uncooperative cartridge, you do not have to suck on
the business end. You can gently blow into the top vent (located on the
top of the cartridge, inside the green arrow) to prime it. But be careful!;
If the jets are severely plugged, ink may blow out the check-valve on the
bottom (under the plastic 'flap' with the 'maze-like' area). Very messy!
Have a towel ready!
The old DeskJets were (and still are) notorious for paper feed problems as
they age. This is caused by the three big paper pick-up rollers drying out
and becoming hard and smooth. Roughen them up with some rough sandpaper.
The HP FTP site has a article about this in the DeskJet DOC directory. A
free kit is available from HP (to qualifying S/N#'s) that 'dresses' the
rollers (basically forces the rollers to turn and sandpapers them).
OH! Biggie! Another big 'failure mode' of the early printers is that the paper
sensor lever will jump out of position and jam if the printer has suffered
some rough handling (especially if it was turned upside-down or on it's side).
The paper sensor lever (pivot) is located on top above the middle roller. The
other end breaks the beam of a photosensor. The 'interrupter' end will move
over just enough to wedge itself above the photosensor. This is cured by
simply raising the lid and wiggling it until it drops back into position (I
have 'fixed' many an alleged 'broken' printer this way). The 'interrupter'
end seems to have been made larger on the later printers to prevent this.
From time-to-time, the cartridge's nose should be wiped clean with a soft,
moderately damp cloth (~ every 100 pages). Keep the 'business' end pointed
down when handling/cleaning the cartridge (Yes, this means hold it above you
and clean it from the bottom!). This keeps the galleys and jets primed.
I concur. If just *one* jet is not firing, then it is on the driver/flex-
cable/connector/cartridge side. All the nozzle decoding is done on the driver
board, so the 20 pin interconnect cable is okay. The DC (well..really 20VAC)
power connector does take some abuse in normal service, this could have
aggravated the cold joint.
Don't forget to check the buttons for water damage/contamination.
Do you know what the difference is between the DeskJet and PaintJet
cartridges? There is at least one contact that is open on a DeskJet
cartridge and wired to something on a PaintJet cartridge.
I also have a color PaintJet 300 with a possible "dead" driver line, but I
focused my attention to the ailing DJ500, so I did not have a chance to
"buzz-out" the PaintJet cartridge. From looking at it, it looks like the
PaintJets are multiplexed in some way (there are more jets/contacts than
wires in the flex-cable). I never got around to fixing/looking into it (it's
still sitting there).
BTW 1; The DeskJet, DeskJet Plus and DeskJet 500 (non 'C' models) are basically
the same (except for some internal fonts). The DeskJets speak PCL, so if a
driver for a DeskJet is not available, you can use a basic HP LaserJet driver
(but the margins may be cut off, as the DeskJets print area is not as big).
These things are so damn simple that not much can happen to them. I have
yet to run across one with a severe electrical problem. They are always
minor mechanical failures (or missing power bricks...$35 from HP).
All the DeskJet/DeskWriter printers, up to and including the 6X0 series, use
the same B&W cartridge as the original DeskJet. Those cartridges will still
be available for some time. Your printers life is not over any time soon!
The DeskJets are good, sturdy and reliable printers (as long as they are
well maintained) You did clean the rubber cartridge seat and flap. Right?.
BTW 2: For maximum cartridge life, make liberal use of the "draft" setting
for "not-so-important" printouts (or, er, um, drafts!). It also prints
faster because it "swipes" once per line instead of twice.
BTW 3: Use the cheap 'Shark' brand inkjet paper for best results. Pretty near
laser quality! Regular copy paper tends to bleed, but is fine for general use.
Can you tell I have a 'few' of these printers around???? ;^)
At random times, the print will fade out and require priming by mouth
to restore operation. This can be anywhere from a few lines to a few
pages. Until it quits there is no evidence of a problem. Blowing into
the vent hole will restore operation. This happens with more than one
cartridge. It appears as though the ink is just not refilling after
being vaporized.
Is the cartridge full? As you get down to the last 20% or so of the
cartridges capacity, it tends to start doing this. I guess there is not
enough pressure "from above" to force the ink down. If you can start seeing
through the cartridge, you are probably near this point.
In troubleshooting the printer, you tend to "burn up" cartridges a *lot*
faster than in normal use.
This can be a symptom of the print head not seating firmly when in the
"parked" position. Use a dental mirror and make sure the seat presses
firmly against the head. One cause of this can be turning off the printer
before it has a chance to run through all of it's "housekeeping" cycles at
power-up, reset (re-boot), or after printing. During certain parts of the
cycle, the head is moved slightly, or the cover is moved. Turning off the
printer too soon may leave the head exposed. Always let it finish, then
turn it off (warn others about this).
If you haven't already, just pull the thing apart and give it a good
overhaul (get your favorite pair of Torx bits ready!). Clean all the rubber
tires, seals and "nose wipers". Wipe off the slider bar to remove any old
lubrication. If there was a serious ink leak and the printer was involved
in some "circus acrobatics", some of the ink can get on the slider bar and
contaminate the factory lubrication, causing it to become "pasty". I wipe
the slider bar clean with a cloth then apply a *light* coating of a light,
teflon-type machine oil with a cloth (I use "Tri-Flow", a spray-on type
usually found in bike shops).
BTW 4: In the winter months, with it's low humidity, the rollers will shrink
even more, causing even more paper feed problems. This is also compounded by
the fact that the paper sometimes develops a static charge and tends to "stick"
together. Sometimes it pulls two or three sheets in at once, or the paper
sticks firmly together in the tray and the weak, dry rollers cannot pull
the paper in. Just remove the stack of paper and "fan" it out to loosen it
(especially if it has been sitting there unused for a couple of weeks).
These printers are, like some other things we won't mention, 'Use `em or
loose `em'! They work best with frequent use. They do not like sitting
around for months unused. Three months seems to be the limit before a
'good' printer will start to dry up from no use.
How is pulse width determined in these things?
I never really investigated the timing of the pulses. I'm not sure how they
vary the pulse width. I looked at the pulses when it was doing the first
page of the self test, which is mostly text, and all the pulses seemed to
be the same width.
Happy printing!
The ThinkJet is VERY simple. The ThinkJet printers (and clones) do not employ
any type of printhead covers or 'priming stations', so the cartridges are
prone to drying out if not used for a while. A quick 'priming' is usually
required, even after only a week or two of non-use.
The cartridges also tend to leak if placed in odd positions or subjected to
rapid temperature changes. Make sure the cartridge has not drooled on itself
and caused ink to cake down on the contacts in the holder. Clean the gold
contacts *gently* with a cotton swab moistened with rubbing alcohol.
BTW: Like motor oil, fresh ink is great for cleaning up old, dried-up ink.
The ink is contained in a rubber bladder inside the plastic shell. There is
a hole in the 'butt-end' of the cartridge. *Gently* stick a bent paper clip
in and push on the bladder to prime it. A drop of ink should form on the
printhead. Use a piece of tissue to wipe the drop off and re-install the
cartridge.
Note that there are two types of HP ThinkJet printheads. One is the older,
original type meant for printing on special 'ThinkJet' paper, and the newer
'Plain Paper' ones meant for, well, plain paper! ('PLAIN' will be printed on
the side of the cartridge).
The older cartridges printing will appear very light if printed on plain paper.
Make sure you have the 'Plain' type. Note that even with a 'plain' paper
cartridge, the printing is lighter than a Laserjet or DeskJet, especially in
draft or single pass modes. Don't expect razor sharp printouts. This was the
first Inkjet printer!
As for the missing jets, eyeball the cartridge contacts and see if they appear
straight and aligned correctly. The contact area could have slipped and may be
out of alignment (although rare).
The flex cable/connector assembly is held in place with a pair of plastic
bars. The "bars" have two pins that snap into the 'carriage' (they also
provide alignment).
If the contacts appear to be out of alignment, carefully pull out the plastic
bars to release the contact pad, realign the holes and press them back into
position. Make sure the rubber 'bumps' behind the contacts are clean and
undamaged.
(This makes more sense when you actually see it :^))
Be careful! Nothing needs to be forced.
I'm wondering, could the voltage to the cartridge be too low?"
(From: Kevin).
I have seen on rare occaisions the cartridge bad out of the box! Try wiping
down the cartridge head & contact points on the printer with a Q-tip & alcohol.
Sometimes blowing in the vent holes will force ink out the head, wipe off
excess and try it. You may have to repeat the procedure a few times. If this
doesn't work get another cartridge. You may want to try swopping the bad
cartridge into a working unit or taking a working cartridge and putting it in
the suspect printer.
(From: Frank Reid (reid@indiana.edu).)
I agree with all Kevin said. I use blue window-cleaner (e.g. Windex) instead
of alcohol; the ink is very soluble in that stuff, and it penetrates the tiny
holes in the printhead. After cleaning, hold a rag over the printhead and
sling it downward a few times (as if throwing, but don't let go), such that
centrifugal force pushes some ink out. If that doesn't work, try blowing on
the upper vent.
On a few rare occasions I've encountered bad connections at the fixed end of
the printhead cable, fixed by reseating the connectors. Also, if the cartridge
has leaked, there may be ink on the gold pads in the moving end of the
printhead connector, causing bad contact. Clean as above.
Some of the later models, including the type which takes two cartridges
(3-color and black), have screws at the end of the carriage rod which allow
adjusting the clearance between printhead and paper. Those may need adjusting
if the ink is smearing. If too light, it's probably a printhead problem.
(From: Richard M. (Digitech@bogus.net).)
It is a water based ink. There is no need for any solvent other than water.
Warm water works well. Use it all the time on my 1200C and DJ750C... BTW, I
never have to touch my Epson. Use lint free cloths to tamp dry. NEVER wipe.
(From: R. Wagner (rwagner@ncn.net).)
I found the cable from the computer to the print head had some open places
close to the head. The want 35 dollars for a new one. I went to the auto
parts store and got some a rear window defroster repare kit. I got it working
but for how long I dont know.
The paper feed problem afflicts the HP DeskJet 550C and 560C, DeskJet 520 and
DeskWriter 520 printers produced between June 1993 and March 1994. The
affected units have serial numbers beginning with 'US3' through 'US43.'
The problem seems to be that the rubber rollers become slick over time and
then the paper doesn't always feed properly. Last year HP offered a free
paper-feed cleaning kit to fix the problem. Try contacting HP at 800/656-2324
or 510/657-1473 (FAX) to find out if the free kits are still available.
(From: Allen E. Amey (a_amey@ix.netcom.com).)
Try contacting the manufacturer. I have heard that HP has a free kit for
the 500 series printers. The kit dresses the rollers and is supposed to
be a fix for the type of problem that you are experiencing. BTW, using
alcohol can actually compound the problem by prematurely drying out the
rollers.
(From: FaxRepair (faxrepair@aol.com).)
I believe the only replacement part would be the entire paper pickup assembly
which may need to be replaced because the gear train is damaged
from ink having dripped onto it. Once the gear train is out of timing
there is no known cure. Clean the rollers with rubbing alcohol and a soft
cloth. If it doesn't pick up the paper after cleaning the rollers, then
remove the entire print assembly and look for signs of ink on the gears at
a location directly below the ink cartridge's home position. On a few
occasions I have had success by flushing the gear mechanism with warm
water to wash away dried ink.
(From: James E. Burke, Jr. (jeburke@ibm.net).)
I fixed one for a friend a couple of months ago. Parts are not available
(well, you can get them, but they're too expensive).
In the one I fixed, it was a broken plastic part that caused the misfeeds. To
get to the part, I had to disassemble the whole printer.
If you decide to to this, check the two 'fingers' that are behind the
print head when it's in the parked position. The hook on the tip of
one of them was broken off. I found the broken part inside the printer
and glued it back on with JB Weld (twice--first time backwards). The
pair of 'fingers' are identical so you could probably swap parts from
one of the other machines instead of attempting the
repair of the "fingers".
(From: Paul Grohe (grohe@galaxy.nsc.com).)
I have the same problem.
The rollers dry up and become glazed-over and smooth. You need to 'rough' them
up.
Try sandpapering the wheels with coarse sandpaper (100 to 200 grit).
You'll need to trick the paper sensor. Take the cover off and
lift-up on the black paper sensor lever. Then hold the piece of
sandpaper firmly against the wheel and hit 'FF'. You'll need to
do this repeatedly, as the wheels will only spin a sheets' worth
each time.
Do this until the wheels feel 'sticky' again.
It also helps to keep the paper tray full at all times (but not overloaded).
Unfortunately, they'll never be like new.
(From: Frank Reid (reid@indiana.edu).)
I've had very good results cleaning the rollers with naphtha or mineral
spirits, no sanding. It removes the glaze from the clay content of the
paper, and makes the rollers softer.
(From: (Egiglious Giggles" (chsoccer@prodigy.net).)
The thing I have come across, is the spring which is directly under the roller
itself. The purpose is to allow tension on the roller for pulling the paper
in one sheet at a time. If you look directly in the middle under the roller
from the front there is a guide that is spring tensioned. You have to take
the roller assembly apart to get to it. But, if cleaning the rollers doesn't
do the job, this is probably the culprit.
(From: Tony Dunlap (tdunlap@odot.dot.ohio.gov).)
The "Glaze" that gets on the rollers is often due to the rag content of many
cheaper papers (especially "Recycled"). To clean the rollers:
(From: Paul Weber (webpa@aol.com).)
HP had a free upgrade kit for the 560 to solve this, maybe for the 500 as
well. It was a replacement for the silicone rubber park-position nozzle seal.
Also remember that the 500 came with a cartridge storage box with an elaborate
rubber seal in the bottom; they encouraged you to remove the cartridge from the
printer and put in the box whenever it wasn't in active use to prevent
dry-outs. Finally, HP cartridges have expiration dates - and they mean what
they say: If they're out dated, they work poorly or not at all.
(From: Paul Grohe (grohe@galaxy.nsc.com).)
I know this sounds silly, but how old are the batteries?
My guess is that the battery is probably getting weak. Heavy graphic content
and "fancy" fonts users (of which TTax and Netscape qualify) will "swipe" the
head more per line than the "text and lines" of the test pages. Moving that
print head uses a lot of power!
Does the unit work on the adapter - without the battery? If not, then it
relies mainly on the battery for power, and the adapter just charges the
battery in between jobs. A weak battery could be drained after a short time.
If it works without the battery, then the battery could be going bad, causing
the charger to dump too much current into the battery and "rob" some of the
power from the printer.
There is a "Troubleshooting" note in the printers "FAQ" on HP's site.
It basically says to check the batteries and make sure you are using the
correct power supply.
Try replacing the battery. If you bought it at a local store, take it back and
see if they have another battery to check it with.
(From: Tech Guy (patrickmcardle@sprintmail.com).)
You may wish to check the undercarriage (no pun intended).
The printhead location sensor microswitch may be on the fritz The printer
uses this switch to determine the starting point of the printhead after which
it uses assumed location by how far the data has sent the head every time
the unit gets a reset code, it checks this switch and if the signal is not
detected, it may slam the head to either rail end or not move at all. If this
is the case you can make sure that the platen is not clogged with label or
paper debris. Gently move the head by hand to the right. If you shine a
bright light into the area where the printhead usually calls "home" you may
be able to see this switch (it may however be located under a cover
triggered by the belt) if the switch is defective, replace it. If in fact it
is jammed by debris, simply clear it and you may have solved the problem.
Beyond this, you may have a logic problem (bad chip or other component) I
make a good practice of doing a thorough cleaning of all machines that have
left my shop to reduce the possibility of other problems during my warranty
period. (it also makes the customer think that they have gotten something
for their money)
I have replace a switch or a fuse on many machines, charged my base fee and
heard the response upon their pick-up by customers that, "I can tell right
away that you have found and fixed the problem" without even so much as a
demo.
(From: michae98@ix.netcom.com).
There is a clear plastic strip strung between the both ends of the printhead
pathway. This strip of plastic has microscopic vertical bars which the
printhead can read and sense what position its in the pathway. The strip may
be contaminated with excess ink which may confused the printhead. Take a soft
cloth or Q-tip dampened with water and wipe of the strip (the ink is water
soluble) and the printer should work.
(From: Raymond Carlsen (rrcc@u.washington.edu).)
Closely examine the toothed belt that drives the printhead. Look for a few
missing teeth at one end. I managed to make one work again by shifting the
belt over a bit (past the bad teeth). If that's it, the belt should of course
be replaced.
First let me describe mechanically what it is doing. When it gets to
the point in the power-up routine where it moves the print head, it
should do the following:
OK, here is what it is doing (please forgive my feeble attempts to
describe in words what is happening):
The end result is that the print head winds up about 0.5" to left of
the position it was in when the unit was powered on. If I continue
the power on sequences enough times it will end up at the extreme
left and will be accompanied by a much uglier, more sinister sound
of the print head slapping against the leftmost guard (as if the
printer is attempting to throw the print head through the case).
Now let me describe the sequence that happens with the LEDs. The
control panel has 9 LEDs arranged in three columns of three LEDs
each. The leftmost column of LEDs lies between the "CLEAN" button
at the top and the "Font" button at the bottom. The middle column
of LEDs lies between the "Alignment Test" button and the "Status"
button. Finally, the rightmost column of LEDs lies between the
"Install Print Cartridge" button and the "Quality" button. Here
is some ASCII art:
Here is the sequence that the LEDs progress through each time the unit>is
powered on. The sequence is always the same.
** Step 5 is the point where the printer starts moving the print head."
(From: Jason D. Pero (JDP6640@ritvax.isc.rit.edu).)
The grinding sound from priming area is the jammed lever black stick
that is pushed towards a bit towards right. If it good, it should be
in upright position. If stuck too very right, unstick it by pushing
it back to upright position towards left. This stick can be seen
between the carriage rod and the printhead's purging rubber nipples
and wipers. Also clean (gently!) the clear plastic strip with that
fine black lines on it. First the clear strip must be removed
first before doing this operation: The sensor is behind the printhead
riding the clear strip, remove it by unengaging two triangular
fingers inwards from outside and pull the sensor unit outwards
towards back. Dust off inside that sensor gap and snap it back in.
Finally clean and oil both carriage rod and the angled underside area
where the bearing block contacts upward onto it. Oil that carriage
motor carefully and all stepper motors.
That should solve everything. This have happened to my 520, and my
friends' 540 and 560C. Pretty common problem! Usual action when
misbehaving is slamming either stops or do a "rushed start/stop" and
some odd scary noises. All complains with pretty, interesting
alterating flashes from the LED's on the control panel.
Pure or almost pure alcohol stuff is best as it does not melt
anything or rub marks off and some 2 in 1 heavy duty oil "blue band"
can. Top and bottom white shells comes apart easily after unengaging
four snaps, doing one at a time and pulling gently and with a small
flat screwdriver. Top off, the engine is free. disconnect with care
to both ribbon cables one for carriage motor, and the flat white
ribbon, or in some models that uses dual printheads, unplug another
stepper motor. All connections you need to worry about is only from
the mainboard side. Then the print engine lifts out without any
fastening hardware.
WELL DESIGNED 5xx series compared to many printers past and now!
I have a 520 chugging away after this fix and real cheap for that
printer from a owner who does not want it.
Only problem is cost of cartridges. :( $50 of two versus $13 can of
toner powder for an Okidata 400 that will last thousands of papers.
Only problem is Oki. 400 LED laser thinks (processing graphics) very
slowly. Is there a hack to swap the proper circuit boards from
other similar Oki 400/800 series to make it work faster and more
useful than a pokey 186 cpu equipped Oki 400???
Your comments and suggestions on which brand of refill inks that is
perfect for those cartridges. I know how to refill it right after
experimenting on a bad cartridge and successfully refilling one good
cartridge from a bad cartridge (dead jet out of 48 jets I think).
(From: Glenn Allen (glenn@manawatu.gen.nz).)
It is not a stripped gear is it?
The old DJ500 used to have 2 levers on the right hand side at the back that
went up and down. Sometimes these got stuck and noises could be heard. Normal
paper feed problems here.
A problem with a DJ850 was that paper got stuck and to get it out I had to
remove the paper feed motor on the drive shaft, when put back it would bang
the left hand side of the case. Needles to say it needed the cog setup back to
right place it expects when powered on.
Those printers have an index strip that the printhead follows doesn't it? Is
this clean, i.e. Not ink all over the place.?
Lastly if you are repairing and turning your printer up and down, check you do
not lose the rubber cap where the printhead sits, and clears the guns, If you
do your cartridges will become clogged in no time.
Also clean the print head shaft, any gunk on it will cause the printhead head
to stick thus giving error light or worst powers down the printer.
The HP printers test for the presence of a cartridge by checking the
electrical voltages on the contacts between the cartridge and the cable.
The slightest amount of dirt on the contacts can give a false reading
making the printer think that no cartridge is present. If cleaning the
contacts does not work you will have to buy a new cartridge.
(From: Dennis Bathory-Kitsz (bathory@maltedmedia.com).)
For this last, there may be some diagrams accessible via the
HP Support Page.
The bad news is that the plastic these parts are made of seem to be a Teflon
hybrid and even the best epoxy doesn't last real well.
The even worse news is that DeskJets are disposable, just like Bic lighters.
HP will NOT sell you any internal parts.
They will not sell them to your dealer.
They will not even sell then to a so called HP service center.
All DeskJet service takes place in Corvallis, Oregon. A second possible
location is Mississauga, Ontario but I think they just forward printers to
Corvallis.
Here's the deal as I've been told; you pack up your printer and courier it
to Mississauga, ($40 Cdn.), pay $175 Cdn. for a refurbished version of your
Deskjet, and then pay another $40 Cdn. to ship the refurb back to you.
That's $255 Cdn for a used printer when there are any number of new
printers that can be had for a comparable price (and would also have a
warranty).
That, to me, means DeskJets must be disposable because nobody in their
right mind would pay that much for a three or four year old printer.
It's bad enough when you consider 540's, which back then had a 3 year
warranty, think about all the poor suckers buying newer HP's with only a 1
year warranty...
That's got to be enough harping on my part, the short of it would be that
if you've got it working and your cartridge parks okay, it might be best
to leave it alone. You won't get any worthwhile out-of-warranty help from
HP. Check on parts availability on any future new printers you might ever
buy. You can't assume that they won't forget you the day your warranty
expires.
For a printer made in 1992, it can sure last a long time. I must have opened
it up about 20 times though.
The most serious problem happened recently when the printer switch was
turned on. The LEDs would flash, and the printer would go off. A quick
search on the Net confirms (albeit a 1200C) that it was some kind of power
supply protection thing. Opening up the print, to my horror, I saw a
familiar oily look around the power supply PCB. Capacitor leakage-again!
The Nichicon 1,800 uF as well as the 2,700 uF had the oily acid seeping from
it and some of the components had green and/or rust on it. First thing -
remove the PCB and washed it under running water, using a toothbrush to
remove all acid and flakes of solder resist from the solder side. Some
copper tracks had completely been eaten through. Others had dark spots
underneath the green solder resist. I removed them as much as I could,
knowing that these would be the source of future corrosion.
I soldered back those points which were meant to be connected and used
insulating varnish on the exposed copper. I got suitable capacitor
replacements. Before connecting back and powering up, I measured the
voltages just to make sure all's OK
(Voltages were confirmed to be correct by checking on the Gnd/Vcc and
other pins of chips with known part numbers on the mainboard.)
Good repairing!
Call HP - After much hassle they finally admitted it was a defect and replaced
it with a new 600 series. I had the same problem - but had to call Idaho to
get results.
(From: Ralph Wade Phillips (ralphp@techie.com).)
Did you also clean the cartridge HOLDER? See HP's web page for more
details, but I've seen SEVERAL of the 600 family that have "dust" collected
under the cartridge holder. Since the black hits at a different angle than
the tricolor cartridge, it is more prone to hitting the dust buildup,
causing excessive smearing.
BTW, beware of flipping the entire printer over to unlatch the top - you may
get a shower of the last n years excess ink from the holding tank!
(From: Paul Grohe (grohe@galaxy.nsc.com).)
Go to this page below, scroll down to the "power module options"
section, and pick the correct adapter part number for the UK.
Then do a net search for that part number, or, contact HP directly. Last time
we ordered some, they were about $35US from HP.
I had a similar problem with a HP 693C. The problem was the spacing between
the paper and the carriage. A suggestion: if you're not mechanically adept,
don't tackle this, get someone who works on printers to lend a hand.
I have not taken my 600C apart, and will not do so unless it fails, so the
following information is based on the 693C, a similar printer.
The top cover is held in place by some latches, and a couple of screws under
the paper tray. Be careful while tipping the printer, there is a catch-basin
for the ink, and if this spills you will have ink dripping inside the printer.
Remove the upper cover. Be careful with the thin cable to the electronics
board. At this point you should be able to check for any gobs of ink that
have turned to paste. Clean the dried ink off of everything, especially the
bottom of the carriage, and print a test page. If it still smears, it's time
to try adjusting the carriage height.
On the 693C the carriage slides on a rod that runs the width of the printer.
The anchors consist of a screw through a slotted hole. On the one I fixed,
the screws had obviously been loosened (they're torx screws, and it was
obvious that something such as a jeweler's screwdriver had been used on them).
Anyway, loosen the screw at one end, lift the rod slightly, and retighten.
Print a test page, and repeat if it still smears. Of course, if it now smears
only at the other end, it's time to switch ends.
I'm sure at the factory they use a gauge to adjust this to within a micron
but the empirical approach worked for me.
I did a search when BOTH of my HP692C DeskJet printers started getting flaky.
I didn't find much except for a post mentioning that cleaning the small
plastic 'barcode' may solve most problems. While this is exactly what HP
customer service suggested as well, it didn't solve my problems.
What the printers were doing, were randomly locking up. They also started
making a 'knock' sound while they were printing. But, the 'knock' sound was
more prevalent than the actual 'locking up' problems. But they would still
lock up more than twice a day.
What I found was happening was that the stepper motor belt was skipping a
tooth when the print head was changing directions. There is a black plastic
tensioner arm on the left side of the printer that holds the belt tight and
this was getting yanked in enough to let the stepper belt have some slack.
What I did to fix this was to take the spring out from behind the black
tensioner arm and stretch it out to put more tension onto the stepper motor
belt.
Both of these printers have had heavy use, they both are just over 1 year
old right now too. I only moderately stretched the first spring and it still
made the 'clicking' noise every so often. On the second one, I probably
stretched it about 1/2" to 3/4" in it's fully relaxed position, but I think
when putting it back into place it probably bent back a small amount. This
worked well, the belt did not feel overly tight and I have not had ANY
problems whatsoever. :-)
I've been having a problem with the black cartridge in my HP 820Cxi printer
getting all gummed up with ink on the bottom, making lousy print. Clean it
off, and it comes right back. It also was missing a horizontal line or two -
thin but noticeable. The "clean" instructions with HP troubleshooting didn't
help at all. Interesting that they say there is another thing you can try, but
don't do it except with NEW ink cartridges! At $30 or so each, I wasn't
interested in trying that except as a last resort.
The other day, after cleaning and refi
All Rights Reserved
2. There is no charge except to cover the costs of copying.
DISCLAIMER
Some of the procedures described in this document require access to dangerous
voltages, hazardous laser radiation, moving mechanical parts, and other
potential risks to personal safety and damage to equipment and property. The
authors and contributors to this document will not be held responsible for any
direct or collateral damage which might result from following the suggestions
or recommendations contained herein including but not limited to: shock,
burns, electrocution, vaporization, meltdowns, torn flesh, destruction of the
equipment, and local or planetary wide power disruptions or implosions.
Introduction
Most of the articles in this document have been compiled over the last few
years from postings on the USENET newsgroup sci.electronics.repair. I cannot
vouch for the accuracy of all of the recommendations they contain but have
edited out anything I felt was totally bogus. I apologize if your response
is not here - it could have been that I missed the posting and will welcome
contributions.
SAFETY
Also see the document: Safety Guidelines for High
Voltage and/or Line Powered Equipment.
Printer and Photocopier Technology
Dot matrix printer operation
These are the only type of impact printers still in wide use. A set of steel
pins - typically between 9 and 24 - strikes the paper through a fabric or
carbon film ribbon. The pins are activated by solenoids which are controlled
by the printer's control logic. Multiple passes may be used to increase the
effective number of pins and improve print quality (letter versus draft mode).
Daisy wheel printer operation
These may still turn up at yard sales and flea markets but have virtually
disappeared due to slow speed and limited flexibility with respect to graphics.
In their defense, for basic text, their quality is superb for a low cost
printer.
Ink-jet printer basics
(From: Tony Hardman (AHED_CIJ@f54x19.demon.co.uk).)
A primer on priming
The priming station of a typical ink-jet printer (e.g., HP DeskJet 500C)
includes a rubber seal ('boot') and small pump to actually suck on the end of
the print cartridge to free up nozzles (there are 50 or more in a typical
print cartridge) that have dried up or become clogged. It may fire all the
nozzles at some point during this process as well. It also includes rubber
'flappers' which the end of the cartridge pass over to wipe off excess ink.
A bit of ink-jet history?
(From: John Nagle (nagle@netcom.com).)
Inkjet types (at least from a Xerox perspective)
(From: Peter (hedgieus@yahoo.com).)
Response times of resistance heater elements in ink jet printers
The ink drops that make up the 'image' on the paper from an ink jet printer
are expelled by microscopic resistance (thin film or the like) heaters with
response times in the 10s of microseconds if I recall correctly. When
living in the macro world, it is often counterintuitive to realize that a
resistance element can have such a fast thermal response.
How many colors can an ink-jet printer can produce?
"I use a HP680C in the office, and it have two cartridges, one for black and
one for color (yellow/cian/magenta?). If the printer fire one drop of each
ink at a given point, we can have only 6 different colors (ignoring white and
black). If it can fire two or more drops at a given point, maybe we can have
more colors, but I suspect that the printer use this to control quality of
the presentation, not the number of colors. Anybody knows for sure? With
dithering it can make more colors, with reduced resolution."
Why are red, blue, and yellow inkjet primaries?
For a subtractive printing process, the 'optimum' primary colors for a 3-ink
system would be closer to magenta, cyan, and yellow. However, these are not
generally used. Why?
About inkjet printer ink
No, you can't refill your HP DeskJet cartridges with fountain pen ink!
Laser printer and photocopier operation
Copiers and laser printers have a lot in common. The major difference
is in how the image is formed on a photosensitive drum:
Laser printer operation summary
(Portions from: Zaki (zg@ix.netcom.com).)
Cleaning and Handling of Photosensitive Drums
Where the drum is located inside a replaceable toner cartridge, there is no
need for special handling. However, where the drum is a separate unit, the
following applies. Or, if for some reason, you need to disassemble (gasp!) a
cartridge:
Book on laser printer maintenance and rapair
(From: Michael (ncacaver@aol.com).)
Discussion on laser diodes in laser printers
"I just acquired the optics from a dead laser printer and have been trying to
understand it. There are two functions I have yet to grasp. One is something
which it has but for which I see no need. There seems to be a heater
(Contains mica) and a thermometer, with PCB markings like "T1" and H2" or
something similar. If these the laser is temperature controlled, why? There
seems to be a control photodetector to monitor the laser diode so temperature
control appears like overkill unless the photodiode itself has too much
temperature dependence and the drum exposure is very critical."
"The other thing is something I cannot find, the aperture defining the nice
well-formed pixel. So far I must admit the study has been a bit superficial
but the aperture ought to be pretty obvious if there is one!"
"Finally, how are the correction lens made? They look like slices out of
the middle of some fair sized lenses, but that would be a very wasteful
way to make them. Can they be diamond formed to nearly the final shape and
with such good finish so only a simple polish completes them. Grinding the
old-fashioned way on a sliver of glass looks doomed to generating all sorts
of defective approximations to a sphere. (As far as I can tell they are
glass, or some wonderfully hard plastic I would like to know more about!)
Can they be molded to sufficient precision? (The sides are ground or sawn.)
Thanks to anyone who can bring me up to date on lens fabrication technique."
Types of toner
(From: Lionel Wagner (ck508@FreeNet.Carleton.CA).)
So you put in the wrong type of toner?
"I have a 3M Model 6312 copier. I believe it is a re-badged Lanier. I
didn't pay much for it but it worked well. When the toner warning
light came on, I made the mistake of adding the wrong kind of toner.
I removed the wrong toner as much as I could by vacuum. Is there
anything I should do before adding the right type of toner? Did I do
serious damage to the system? What to do if the warning light
remained on even with the right type of toner added? Any suggestion
will be greatly appreciated."
Dot Matrix and Daisy-Wheel Printers
So you took your printer apart....
"I stupidly took apart my Panasonic KX-P1123 to attempt a head swap (the cable
was too short!), now that it's back together it just beeps when I try to
print. The only things I touched were the rod that the head assembly slides
on and the toothed belt also had to come off (I don't think it's a timing
belt.. there's no clear markings suggesting that). When I try to print, the
head moves to the center, there's no pin action and it starts beeping at two
second intervals (and won't stop). It's not the paper sensors because they
seem to work properly...any ideas?"
Print head repair
"I have a few Epson dot matrix print heads with stuck or sunken pins.
Does anyone have experience with disassembling these things for
cleaning/repairs? It looks like you just have to pop a few clips
to get them apart."
Ribbon does not advance after replacing flex-cable
Have you actually confirmed that your 'new' ribbon cables are making proper
contact - with an ohmmeter? Assuming that the thing worked better before
the cables were cut, then there are only two possibilities: your replacements
aren't quite right or something was damaged by the 'event' or through later
actions.
Print head stepper
Confirm that you simply don't have bad solder connections around the plug to
the motor. This is common in printers and will result in erratic or incorrect
motor movement.
Motor driver blows fuses
The following was in response to a dot matrix printer blowing the power
fuse whenever the paper advance motor was driven. A 74LS273 was getting
hot as well:
Ribbon on electronic typewriter does not advance
"My wife has a "Smith Corona" Model SD800 electronic typewriter that will not
advance the ribbon. Everything else seems to work fine. We have been unable
to find a local repair for this unit. I think I can fix it with some advice
from someone familiar with these machines."
Apple Imagewriter II squeal
"My Imagewriter II, after many years of faithful service (~8), is starting to
squeal. It squeals when the carriage moves. It still prints perfectly fine,
but....a new noise can only mean trouble. Does anyone have any experience
with this problem and his solution? I imagine it would take only a drop or
two of lubricant. But where?"
Compaq Pagemarq 15 printer service mode
(From: Darren Mckillop (Darren.Mckillop@gecm.com).)
Epson FX-286e printer problems
"I just received the above printer in a non-working condition. It
exhibits the following symptoms:
"I know if you keep voltage across one phase, you can lock a stepper. If
you lose power to one phase, will the other phases keep it going
provided you manually start it like I'm doing?"
Paper debris clogging Epson LQ-570
"I have an Epson LQ-570 series dot-matrix printer that has developed an
intermittent paper feed problem over the past year or so. It uses a
push tractor for sprocket-feed paper, and paper tends to bunch up
under the platen. There doesn't seem to be an obvious way to remove
the platen to see what the paper's catching on, indeed the FAQ on
Epson's website says it can't be removed, and to bring it in to the
dealer for repair."
IBM X-24 Proprinter print head jumps around
"Got a problem with a real nice 24 pin dot matrix printer I bought used.
Was working fine for awhile then all of a sudden it will be printing fine
an the printhead intermittently will jump to the center of the carriage
and start printing from there. Also, when you turn it on, many times the
printhead jams over to the right side of the carriage and the gears grind
and you have to cycle it on and off to get it to start up right. Then you
now almost for sure it will have problems printing. Help, any ideas? Do
I just change a control chip? How do you scope out something like that?
Can I get a manual somewhere? I want to keep the printer."
NEC P5200 Printer problem
"I have a NEC printer that has an intermittent CE (ribbon cartridge empty)
problem, only the cartridge is new and good. Anyone knows what senses
this condition and what part could be affecting this? NEC wants $20.00
just to talk to me. Thanks for any help."
OKI Microline 391 Elite Problem/Error
"I am having a problem with a OKI Microline 391 Elite. I opened it up and
cleaned out the dust and paper from inside. On putting it back together
and powering up, The SEL light, the COURIER font light, LW and 10 cp light
are all flashing and the stepper motor for the platen is jigging back and
fore about once every 3 secs."
Star SD15 printer self-test problem
"This printer has a problem I am lost with. When I power it up and
attempt to have it perform the self-test printout (FF on power up), the
print head moves back and forth, the paper feeds, but the pins don't
actually fire. However, if I connect the printer to a computer, the
printing is just fine."
Ink-Jet Printers
HP DeskJet problems
This of course also applies to other HP printers as well!
Types of HP ink-jet technology printers
(From: Paul Grohe (grohe@galaxy.nsc.com).)
Dissertation on HP DeskJet repair
These comments are in response to: "Repair Brief #49 - Part 1: HP DeskJet
Professional Printer - Dead" and its followups. My text is indented. See
those articles for details. The quick summary is that I picked up this
printer at a garage sale and first had to dry it out and repair some cold
solder joints before it would print at all.
I believe it to be an original DeskJet.
Now, how to do a self test? Fortunately, the complete HP users' manual
was part of the deal. "Hold the FONT button while turning on power".
OK, no problem.
Going back and forth, they are consistent. I am not sure if one of the
two missing lines are the same on both cartridges. Could something be
marginal or is the priming not working? However, all other nozzles seem
to be rock solid. Reseating the connectors to the print head makes no
difference. If I knew which drivers were involved I could look at the
signals but it will be difficult to trace the circuitry from the driver
board to the actual nozzle.
Comments: I suspect the original problem resulting in the dead printer to
have been a cold solder joint on the DC power connector which I repaired.
I don't really think that the nozzle problem was caused by the water since
the print head driver board was never wet. Since the data connection to the
print head driver board is a 20 pin cable, this must be a common bus and thus
it is unlikely that any failure on the main logic board could manifest itself
as a single or pair of bad nozzles. Stay tuned.
Been there, done that. The FONT button was Coke-logged.
The missing line problem turned out to be bad connections between the
flex cable and the gold contacts on the print cartridge due to the flex
cable shifting position on its indexing pads.
As noted previously, the HP DeskJet series in general is a well engineered
design with only a half dozen basic components. While my (DeskJet) printer
is one of the oldest models, the fundamental design has not really changed
dramatically in the last several years as evidenced by the fact that print
cartridges for some much more modern printers work just fine in this old
machine.
The print quality with a new cartridge is nearly laser-quality. Yes, HP
seems to come out with a new, faster, cheaper, color. etc. printer every
few weeks. But, looking inside newer printers shows that their basic
design and construction is quite similar.
Just when I thought all was well....
CAUTION: I found out the hard way that you really do not want to stick
anything into the vent hole - ink all over the place as the vent valve
must have been damaged by this mischief. I 'salvaged' the cartridge with
a blob of silicone sealer. I don't know what the long terms implications
of this 'repair' will be.
I cleaned out the priming tube which was *totally* clogged with dried ink
and it seems to be much happier now.
Before I 'discovered' the priming problem, I has visions of a serious
electronic problem like an intermittent resulting in the nozzle drive
pulses getting messed up at random times.
The conclusion: After several years of faithful service (the most serious
problem being that I really used the printer so infrequently that the
cartridges invariably dried up!), I was given an HP DJ1000C with a couple of
broken plastic tangs to which the pressure roller springs were attached.
Some overzealous paper unjamming had caused thses to snap - not really a
quality problem. Thanks to some stiff wire and Duco(tm) cement, the printer
is better than new forcing retirement of my trusty $5 original DeskJet. :)
HP ThinkJet printer repair 1
(From: Paul Grohe (grohe@galaxy.nsc.com).)
HP ThinkJet Printer repair 2
"I have an HP ThinkJet 2225C printer. I just replaced the print cartridge.
It still doesn't print dark enough, and even after I primed the cartridge a
few times, it still also misses a dot at the top and the second one from the
bottom.
HP DeskJet paper feed problems
(From: John T. Black (cz667@cleveland.Freenet.Edu).)
Cartridges drying out on early HP DeskJets
Note that unless the cartridge is almost empty anyhow, it can usually be
revived by patting off the caked ink with a damp lint-free cloth and then
gently blowing in the vent hole on top until a drop of ink appears at the
print head. Sometimes this may have to be done more than once. NEVER poke
anything into that vent hole or you will have a mess!
HP DJ340 shuts off during printing
(This may also apply to other battery powered printers.
"Whenever I send a heavily formatted print job to a DJ340 printer, it prints
1/3 to 1/2 a page and then power shuts off! This so far has happened in
TTAX97 and Netscape 4.03. OS is Win95 and I'm using the latest driver for
this printer. The printer otherwise prints test pages and simple jobs OK."
HP DeskJet 520 - Crunch!
"I just picked up an HP DeskJet 520 printer that doesn't work. On startup,
the print head moves right an inch, then all the way left, where it slams
into the left side of the carriage and grinds away for about a tenth of a
second before stopping."
HP DeskJet 560C Detailed problem description and possible solutions
"I have a HP DeskJet 560C, Model C2168A that is behaving badly. When I
power it on initially, it appears to run through a diagnostic self-test
(as evidenced by the sequence of LEDs on the control panel). It gets
to the point where it moves the print head and that is where things
go bad. I think it is attempting to report some sort of error code
because it then flashes some of the LEDs in a repeating pattern
(more on that later).
CONTROL PANEL
===========================================================================
|| ||
|| Alignment Install Print ||
|| RESET CLEAN Test Cartridge ||
|| ||
|| ,--, ,--, ,--, ||
|| ( #1 ) ( #4 ) ( #7 ) o o o ||
|| '--' '--' '--' ||
|| ||
|| ,--, ,--, ,--, ||
|| ( #2 ) ( #5 )Busy ( #8 ) o ||
|| '--' '--' '--' ||
|| ||
|| ,--, ,--, ,--, ||
|| ( #3 )Condensed ( #6 )Ready ( #9 )Econo Mode ||
|| '--' '--' '--' ||
|| ||
|| Load/Eject Font Status Quality ||
|| Paper ||
|| ||
===========================================================================
I have numbered the LEDs (using my own numbering scheme) so that I can
reference them below.
LEDs On Duration Description
----------- ---------- ---------------------------------------
1. 123456789 2.5 secs Happens immediately when I switch the
power on. Then LEDs 234789 turn off.
2. 1 56 0.5 secs This is a flash (longer than a blink).
Then LED 5 turns off.
3. 1 6 2 secs Then LED 7 flashes on.
4. 1 67 0.5 secs This is a flash. Then LED 7 turns off,
LED 5 blinks on.
**5. 1 56 ---- Here LED 5 just blinks on then off.
6. 234 789 This starts the alternating sequence
where I believe the printer is trying
to report an error code.
7. 1 6 This is the rest of the alternating
sequence. The printer then repeats
these two patterns forever (LEDs 234789,
followed by 16).
Cartridge detection on HP DeskJets
(From: Fred Keen (fkeen@repeatotype.com).)
HP Deskwriter 660 printer problems
"My HP Deskwriter is just over the warranty of one year and when I print
text instead of white lines through the type which would indicate to clean
cartridges or replace them, I get black thin lines almost smearing
slightly the text."
Little plastic parts in HP DeskJet printers and HP service policies
(From: Wayne Van Beelen (wbvanb@nbnet.nb.ca).)
HP DeskJet 500 repair notes
(From: kmlee (kmlee@email.com).)
Pins: 1 2 3 4 5 6 7 8 9
Volts: 0 21.2 0 19.76 0.17 -10.56 10.7 5.27 26.8
HP DeskJet 560C - stripping gear sounds and more
"Does anyone know where the problem might lie with my HP printer? The problem
is that when it is turned on, it goes through the reset sequence until it
reaches the park zone, then it seems to miss a gear or something by the sound
of stripping gears, then the lights flash alternately. My workaround to this
is to turn it on, let it start across on it's reset sequence, turn it off,
then right back on, and it will initiate just fine. Another anomoly is that
when printing large color graphic files, occasionally, it will make it part
way through the page and just stop with the same flashing error. After
resetting it, it of course will print garbage unless I resend the data to the
printer all over again. Any ideas? I've left a message on the HP site, but
there has been no response."
HP600C DeskJet produces too much black ink
In addition to cleaning the cartridge, replacing the cartridge, cleaning the
ink "well" and rubber wiper used for wiping cartridge head, using "approved"
paper, printing in econofast mode (less ink), and setting up "transparency"
print mode (gives more time for drying), one thing is often overlooked:
HP DJ power supplies/wall adapters
It seems that this is one part that HP may not totally gouge you on!
HP 600 series DeskJet printer smears even with new cartridge
(From: Bill Rothanburg (william.rothanburg@worldnet.att.net).)
HP DeskJet 692C - Random lockups
(From: Jess Askey (jess@magenta.com).)
HP 820Cxi DeskJet Problems
(From: Vic Zane (vic@webworks2000.net).)