asked Feb 9, 2006 at 7:59am
Unknown Printer

DeskJet 5550 Resume light flashing, Power too, etc

I had 5 DeskJet 5550 printers to work on yesterday, it was a learning experience, (and I've fixed quite a few 5550's).

The first machine had the power and resume lights flashing in sync, that indicated a carriage jam error, I noticed that the service station was not moving, but I could hear the service station motor turning.

The large gear with the angled teeth had popped off the service station, the retaining fingers for that gear had worn off, (I have now started pushing some silicone based grease into the area of the shaft the fingers run in when repairing these).

What the symptom implied is that the service station motor is expecting the motor to stop turning when the sled is driven all the way back or forwards, and when the motor keeps turning it gives a carriage blocked indication.

So now I know there are many things that can cause a carriage jam symptom, (some of them having nothing to do with the carriage), the problem detailed above and:

The encoder strip being dirty, damaged, or it has been pulled off it's mounts

A bad sensor on the carriage board

An actual carriage jam

A bad motor/tach on the service station

A bound up service station.

The next machine would not move the carriages to the center when the cover was opened, this was an apparent failure of the cover sensor, which is part of the main board.

While working on this printer I put my finger on the sensor and the carriage moved to the center, took it off and the carriage moved back to the right, (I was able to repeat this and each time got the same results).

Solder joints looked good, and I wiggled the sensor to see if I could cause a failure or make the printer work, the machine then started working, eventually I found that I could rotate the sensor a few degrees either way, and that if I rotated it CW, (if you were looking at the component side of the board), it worked, CCW and it failed.

If you have that problem and can't fix it by playing with the sensor you can change ink by power cycling the machine, pulling the power plug when the carriages have moved off the service station, and after changing the cartridge start an alignment by doing a "Tap-3 test", (push and hold the power button, tap the resume button 3 times, release the power button).

Next I had a printer with a bad carriage latch, after fixing this it began indicating a paper jam, I suspected the sensor, (it's on the back of the printer over the rollers), but swapping it didn't help. (unfortunately when I figured it out I was the cause of the second error).

I came up with a test procedure for that sensor, check the pin closest to the carriage cables on the connecteor with 12 wires going to it, the reading will be about 0 VDC, (referenced to frame ground), if there is NO paper in the paper path, about 3 VDC if there is, (you can slide a piece of paper into the printer from the back and see the level change).

After proving the sensor good and swapping out the main board, (that didn't help), I tried rotating the feed rollers by hand they turned okay in the feed direction, but bound if I turned them the other way.

Here's where I admit guilt, but knowledge comes with mistakes.

I had disassembled and cleaned the machine after fixing the carriage, and had not put the paper tray back in before turning on the machine, so the tray lift lever was up and binding the feed rollers, the rollers were turning during initialization, but at some point the printer was turning them backwards and indicating a jam.

Main point of that rambling is that two things can cause a jam indication, a bad sensor, or a mechanical bind.

Todays 5550 would power on without errors, but you would hear a loud "clunk", then when you started a test print paper would feed in okay, then the printer would detect an error, the error indication was resume, (attention), flashing, all other lights out. (there is another problem that will cause the same light pattern documented in a later post, ST, 12/04/2006)

Eventually I realized that the clunk was due to the paper feed motor turning too fast, (it was cycling the paper lift mechanism during initialization).

Replacing the paper motion encoder PCA fixed that problem.

The part can not be ordered by end users, C6487-60042 PPR ENCODER PCA. The same part is used in other HP machines including the DeskJet 3820 and OfficeJet V40.

Then there was a different symptom, paper fed in and the carriage moved over it, then paper was ejected and I had a flashing resume light again, after pushing the resume button another sheet fed and printed.

This turned out to be caused by the spot sensor LED not coming on, I removed and replaced the sensor and it started working, this sensor is just slid into place, but resists efforts to remove it. Be cautious disassembling the carriage, the spot sensor cable is very, very easy to damage, I sometimes loosen the 3 black screws that hold the carriage together, but I avoid removing the one closest to the spot sensor, I just loosen it slightly.
by Stephen on Mar 1, 2006 at 1:15pm Add comment
When you run a Tap-4 test on a 5550 it prints a page with it's serial number, the current page count, the last error, and some other information.

Printing the page clears the error code, if a printer has never recorded an error the error code field will be all zeros.

If the machine had an error, but worked when tested by the technician a listing of these codes would be handy, as far as I could determine there was no listing of theses codes.

Here are a few:

90020702 Paper encoder failure, (round timing disc)

90020703 Carriage blocked

9002070E Service station stall

To determine the codes I forced the errors, then printed the config page.

Tap tests are started by holding down the power button and tapping the resume button, (machine should be powered up before you start)

4 taps = config page

1 tap = demo page

3 taps = alignment page

8 taps = continuous "H" pattern, (until you are out of paper)

If the tap test is 2 digits, the fist digit is selected by tapping the "X" button.

Tap-31 = Duplexer test

Tap-32 = Skew test page, (fold it in half ond hold it up to a light)

There are other tap tests, at least one takes several minutes, but the ones documented here are the most useful to me.
by Stephen on Mar 31, 2006 at 10:44am Add comment
Here is a link to HP's listing of light patterns for the 5000 series printers:
by Stephen on Aug 28, 2006 at 7:01pm Add comment
Here's another post of mine with some 5550 information:
by Stephen on Oct 21, 2006 at 10:41am Add comment
Today I received an email requesting help with a 5550 feed problem today, I generally prefer to respond to forum questions so whatever information I post is then available for the next guy.

If I don't respond to a post feel free to email me, I'm an unpaid volunteer, so I might go a days without posting. To email me just click on my name, to learn more about me just click on the crossed tools by my name. (And if you want to give a post that helped you out a "Thumbs Up", then click on the "+" sign in the title bar of that post)

First verify that the back edge of the paper tray is being lifted during the feed cycle. Take out the output tray so you can see better, and a flashlight might help.

Keep the printer level while testing, tilting a 5550 can lead to spilling ink from the service station, tilting the printer with the carriage in motion can cause the carriage to jam, (it will be a mechanical bind that will have to be manually released).

If the paper lifts all the way up, and the rollers slip, then clean them with POW, (plain old water), if that helps I advise using rubber roller rejuvinator for a more permanent fix:

The quick/easy way to clean the rollers is to remove the paper and the back door, print a test page, then wipe the tires while they are turning, the machine will try to feed paper 3 times, if you want to clean some more just press the resume button, I do this about 3 times using Rubber Roller Rejuvinator when I work on any 5550.

If the back edge of the tray does not lift, then you may be able to make the machine happier by manually rotating the rollers a couple of turns, rotate opposite the direction they turn when feeding paper. (remove the cleanout door to access rollers)

If you look inside the printer from the front to the left of the upper rollers there is a white plastic piece that you might think resembles a corner, if turning the rollers didn't help, then push on the front side of the plastic piece and turn the rollers, pushing on the piece engages the lift mechanism, sometimes manually actuating it will make the machine happy.

If paper skews when feeding refer back to "Rubber Roller Rejuvinator", feed problems are typically caused by the rollers in the back, skew by the rollers in the top.

To clean the upper rollers remove the ouput tray and rotate the back rollers by hand while wiping the rollers from underneath, (put your hand into the paper feed area). Cleaning from the bottom you won't end up breaking the upper paper guide, (thing that holds the long skinny metal rollers), it's easy to damage.

If the printer feeds multiple sheets, then the separation pad may be worn or dirty. The quick/easy way to clean the separation pad is to remove the paper and the back door, print a test page, then wipe the middle tire when it's turning, (note the middle tire is not in the center), that tire will be in contact with the pad during some parts of the feed cycle, so it will rub off some of the contamination on the pad.
by Stephen on Nov 16, 2006 at 5:48am Add comment
Remove the SS (Service Station), then remove the board and motor from the bottom front. Take the two screws out of the top and pop the service station apart.

Clean SS:

The orange based cleaner is optional, if you do not have any just use water.

Cut triangle shape out of felt absorber around the old ink build up, throw that bit of felt away. Now your service station can hold more ink, but would be slightly more likely to spill if tipped. Spray absorber with orange based cleaner, then rinse with warm water, a toothbrush can be used to scrub the absorber.

Spraying SS parts thoroughly with an orange based cleaner will help dissolve the old ink. If you start thinking about using alcohol, then click on the crossed tools by my name and read the HP technicians motto.

Rinse thoroughly with warm water, a toothbrush can be used to get out the remaining ink residue.

Clean carriage rail, regrease with Chemplex 710. (light silicone based grease, synthetic would also work) If you do not have any grease for relubing, then leave the carriage rail alone.

Clean encoder strip and timing disc with water.

Remove pickup roller, clean all rollers and separation pad with RRR, use water if RRR not available.

Apply a little grease to the back side of the upper carriage guide, the flange on the top of the carriage rides on that guide.

by Stephen on Apr 22, 2007 at 9:08am Add comment
5 more 5550's to work on today.

The first one has a problem I've seen posted, but had not seen personally.

Paper feeds okay, the carriage moves out over the paper, and then the printer stops with a flashing Resume ,(attention), light, all other lights are off. This light pattern can be caused by at least one other component, but the paper motion will be different.

To start the diagnosis I tried to print a demo page, to do that just hold the resume button down for about 4 seconds, the power light will start flashing, then release the resume buttom.

Paper fed normally and stopped with the leading edge of the sheet about 1/4 inch past the metal roller on the upper paper guide, the carriage moved out towards the center of the printer and stopped, then paper slowly fed forwards for about another 1 1/2 inches, the printer then stopped with the resume light flashing and all other lights out. If the resume button was pushed the paper fed out of the printer, the light pattern remained the same, another push on the resume button and the printer fed paper and printed a Demo Page, (at this point the printer must have decided it could not detect the media type and just went ahead with printing).

What is supposed to happen is when the carriage moves out to the center the spot sensor LED will light, the reflection off the paper will let the printer detect the media type, this information will be sent back to the PC so the driver can determine how to print properly on the loaded media.

Replacing the spot sensor fixed the problem, sometimes you might be able to wiggle the spot sensor and get a better connection to the contacts it is sitting on, but always power off the machine first.

To get the carriage out to the center power on the machine with the cover open, the carriage will eventually stop somewhere towards the center of the machine, then just pull the power plug out of the back of the printer.

The spot sensor is not orderable from HP, I have some part numbers for reference:

C6487-60074 Original Part Number
Q1636-69003 New Part Number

You may be able to turn off automatic media detection in the driver to bypass this problem, note that the driver settings will not change the way the built in pages are printed.
by Stephen on Dec 4, 2006 at 7:51am Add comment
Could you tell me where you obtained this part? I have a printer
with the same problem; the sensor light is not coming on.
Thanks - Anonymous
5550 Cartridge Latch Replacement Procedure

Start with power on.

Open the top cover so the carriage moves to the center, then pull the power plug.

Remove any installed cartridge(s).

Note the positions of the springs that hold the cartridge latches up after you release them, you will be removing one or both of the springs when replacing a latch.

(Note, if only the black plastic piece that pushes the cartridge tight against the electrical contacts is broken you can pop it out of the replacement latch and install it in your machine)

The cartridge mounting frame is held to the carriage board mounting plate by 3 black screws.

Loosen the right side screw a couple of turns, I do not remove this screw, before removing this screw the spot sensor must be removed, and the spot sensor contact strip must be carefully pried off the cartridge mounting frame.

Loosen the middle screw about 4 turns.

Remove the left screw.

Gently pull the left side of the cartridge mounting frame forwards, till the end of the rod that the cartridge latches mount on can be seen.

(remember the springs that hold the latches up, they like to fall down and get lost)

Slide the rod out to the left, you might need to grab the center of the rod with a small pair of pliers to move it.

If you are changing just the latch on the right you only have to slide the rod halfway out, if you are replacing the latch on the left or both latches you will have to slide the rod almost all the way out.

Reverse the directions for reinstallation.
by Stephen on Dec 11, 2006 at 5:59pm Add comment
I've seen this problem a couple of times, in each case it turned out to be the carriage board.

The only way I know to prove the board is bad is to replace it.
by Stephen on Dec 13, 2006 at 9:01pm Add comment

I have been struggling with this problem for the last 72 hours, reading your post with great attention. Finally, i solved the problem, THANKS TO YOU!

what worked eventually was moving the cartridge mannually all the way to the LEFT (not the service station), send a print order, disregard the clutch sounds (very scary), and then - everything got back to normal.

Have a merry christmas and a happy new year,

Thanks again,

by o_eliav on Dec 20, 2006 at 2:12am Add comment
Many 5550 parts are no longer orderable, others can be ordered but only by an Authorized Service Provider.

The following parts were available as of the date of this post:

C6487-40038 SUBCARRIAGE (Under the carriage)
C6487-40091 PUSHER-PAPER 3/4 BLEED
C6487-60020 Service station motor
C6487-60022 Output paper tray assembly
C6487-60097 PCA Malibu Carriage

This list is probably incomplete, I'm just trying to detail some hard to find part numbers that might be orderable.

Addition to this post on 05/07/2007

You can replace or repair the latches with 5650 parts:

C6490-60011 Latch, black
C6490-60012 Latch, color

The latches might still be orderable, but only by an HP ASP.
by Stephen on Dec 20, 2006 at 6:22pm Add comment
I did a really stupid thing one day when the printer was printing it just happened to grab more than one sheet, so I really quick grabbed the paper and yanked it out so it wouldn't jam. Well, since then this dag-on printer won't print anymore.

If I do the Tag-4, Tag-3 and other internal print jobs the printer prints, but when I do an internal Print-Test or a Print-Job from wordpad the printer will only push out blank pages. It acts like it's going to print and then shoots out blanks.

I've tried uninstalling all the software and drivers, rebooting and reloading everything, but that doesn't work. When I do the Tag-4 print job I get Error Code: 90020703

As mentioned above, I see that this codes means "Carriage blocked". There's nothing blocked anywhere that I can find. I've taken the printer completely apart, cleaned all wire connects, checked out the printer-board, and even changed the print cartridges with no success.

Any ideas, what I could be missing?
by steve44073 on Dec 21, 2006 at 7:57pm Add comment
If you print the tap-4 test twice in a row the error code should only show on the first test, (if the printer doesn't get an error running the test).

When the printer gets a carriage blocked error lights flash, so you should see when an error occurs.

Carriage blocked errors can also be caused by a bad service station, the service station motor has a timing disc on it so the printer knows if is moving when it's supposed to, and stopping when it's supposed to.
by Stephen on Dec 21, 2006 at 8:44pm Add comment
Two 5550's to work on today, figured out the first.

Turned on the printer, it cycled the lights, stopped with just the ready light on.

I pushed and held the resume button for 4 seconds to start a Demo Page, (power light starts flashing when the button has been held long enough).

Printer went through the appropriate motions, paper fed 1-2 inches and stopped, paper did not get as far as the 4 metal idler rollers that rest on top of the upper rubber rollers.

Printer was now stopped with only the resume light on/flashing.

I had noticed it sounded like the feed rollers were turning too fast, so cleaning the encoder disc was the next step, after cleaning the disc the printer fed and printed the demo page, but after ejecting the page the power light went out and the resume light started flashing.

Power cycled the machine and ran a Tap-4 test, the config page showed an error code of 90020702, refering up a few posts you'll see that that is a failure of the paper encoder sensor, replacing the sensor fixed the problem, now it's just a matter of stripping the machine down, cleaning and lubricating the service station and carriage rail, and cleaning the rollers with:

This printer has done over 9,000 pages, and will probably do as many more after it's been cleaned up.

The second printer runs a demo page without problems, printing a config page shows a 9002070E error, so I'll be looking at the service station closely. (this printer has over 12,000 pages printed)
by Stephen on Dec 26, 2006 at 1:01pm Add comment
The 5550 from 12-26 had a gunked up service station, after it was rebuilt the printer worked fine, but the Technician, (me), noticed he'd left a screw out of the service station, and so he removed the service station and put the screw back in. (you have to remove the logic board to get the service station out)

After reinstalling the service station the printer started having problems, the printer would start initializing, the service station would move a little, then the power and resume lights would flash in sync.

After some thought I decided that the service station was not the problem, and started looking at the carriage motor as the main suspect, swapping the motor did not help.

Wiggling the plug that connects the logic board to the rest of the printer did help so I began investigating and found that one of the female connectors in the plug had loosened up, I removed the connector from the plug and very gently tightened it by squeezing with a small pair of pliers, (this must be done very carefully as it's really easy to crush the female connector).

To find this problem the easiest way is to use an ohm meter to check continuity between the pins on the logic board and the carriage motor, unfortunately HP color codes the wires for the paper feed motor and the carriage motor both the same.

So here's a little help:

Pins 1 & 2 on the logic board connector are for the carriage motor.

Pins 3 & 4 on the logic board connector are for the paper feed motor.

If you look closely where the connector is soldered to the board, (that's where you want to put one meter lead), you will see the pin towards the front of the printer is on a square shaped pad, the other pins are on round pads, the square pad is pin 1.

Meter between pins 1 & 2 on the board and you will be checking the circuit through the commutator of the motor, compare that to the reading between pis 3 & 4, they should be similar, an open circuit could be either a wiring problem or a bad motor, move the suspect motor by hand if possible and check again.

Apparently when I unplugged and replugged the connector the last time pin 2 didn't quite make contact, so I spent more time than anticipated fixing this one.

There is no service manual available for this machine, and I don't keep any notes on paper, whenever I need to remember something I just log on to the forums and find this thread.
by Stephen on Dec 27, 2006 at 9:26am Add comment
HP 5550 Carriage Operation.

HP DeskJet printers, and DesignJet plotters work with the same basic timing mechanism for the print heads. Some HP printers may have a use a different style service station, but most of this document will apply to them too.

I'll start by explaining some of the components you need to understand to troubleshoot the carriage system.

The Carriage is the thing the cartridges are mounted in, it slides on the carriage rail, the bushings in most newer carriages are made of plastic, (or maybe it would actually be called a polymer, or composite material). The bushings are the pieces that wrap around the carriage rail.

The carriage rail is a shiny round rod that the carriage rides on, it is driven across the rod by the carriage belt, by the carriage motor, at the opposite end of the belt there is an idler pulley, in a DeskJet printer that idler pulley is often called the "Turnaround Assembly".

In a HP printer the device where the carriage parks, (sits at), when the machine is not printing is called the service station, it is responsible for cleaning the print heads, and for capping the heads when you are not printing, (so they won't dry up). The bottom of the service station is the "Spittoon Base", ink is spayed into the base before printing to prime the heads, there is an absorbent pad in the base to soak up the ink. Note that the pad does not always soak up all the ink, so if you tilt an HP printer you can spill the ink out of the service station, (especially if it is a heavily used printer). The piece that moves back and forth in the service station is the "Sled", it was wipers to clean the heads on it, and the caps that keep the heads from drying out are also part of this assembly. The sled is moved back and forth before the carriage leaves the service statio to wipe the heads, this happens after the heads are primed, then the carriage is moved off the service station and the sled is again moved back and forth to clean the wipers.

The encoder strip is a plastic timing fence that looks clear at first glance, but has black lines painted on it. The strip is threaded through an optical sensor on the back of the carriage.

When the printer initializes the carriage has to leave the service station, or, if the machine was powered off when the carriage was somewhere else, whatever spot it is sitting in, and travel the way to the other side of the printer, and then return to it's home position which is the service station.

When the carriage reaches the side of the printer away from the service station it sets that as a reference, then it counts lines on the encoder strip as it travels home, if it doesn't see enough lines before it gets all the way to the other side and can't move any more then the printer decides the carriage must have something blocking it.

Sometimes a service station will fail in a way where the sled does not retract fully, if that failure happens when the carriage is parked then the carriage will usually not be able to leave the service station. If the service station binds when the carriage is off of the station, then the station may not be able to move all the way to that side, and will detect a carriage jam. When the service station binds you might hear a grinding noise as it's motor tries to drive the sled back and forth.

If the encoder strip is dirty the printer may not see all the lines and detect an error, often when the strip is dirty the carriage will move too fast and slam to one side of the printer. The 5550 carriage does not usually slam, it just moves back and forth faster than normal.

I use water to clean the encoder strips in HP printers, water works well on water based inks, if your printer uses ink with another base you might use alcohol, but "ONLY" if the ink is not water based.

One end of the encoder strip is attached to a spring mount, if you wipe the strip starting at the end that is attached to the frame, and wipe only towards the spring mount, then the strip will stay attached to the printer. The 5550 spring mount is on the left side, away from the service station.

A dry carriage rail will cause the carriage to bind, if the carriage does not move fast enough a carriage jam will be detected. Some newer HP printers like the 5550 use grease on the carriage rail, Chemplex 710 will work on a 5550, I advise cleaning off all the old grease if you are using Chemplex as it is not the same as the original lubricant.

To really confuse things the 5550 printers have a timing disc on the service station, and if the service station binds, or the timing sensor fails they report a carriage jam, but as far as I've seen that jam always occurs before the carriage moves.

Now that you know the names of the parts you can search the forums for more information.

Here's a link to diagrams for a HP DeskJet 970 Cxi, the parts are very similar to those in many other HP ink jet printers:


by Stephen on Jan 18, 2007 at 6:10am Add comment
You were Google's first result for the problem I was searching about, and provided the quick answer: The encoder strip was filthy and a quick cleaning fixed the problem.

The printer is a DeskJet 5550 with 22,839 pages through it - and still going strong.

Thank you. - JHeacock
Just fixed a fairly inky 5550, simple problems, broken cartridge latch and one finger on the paper pusher bar.

What was interesting about this one was that the page count was the highest I've seen on a 5550.


Pretty good for an inkjet.
by Stephen on Jan 18, 2007 at 12:24pm Add comment
Is there a reset code. I tried the tap 4 test, hold the power and press resume 4 times, and it ejects the paper at high speed.
by rchouts on Feb 14, 2007 at 8:32am Add comment
The only reset is pulling the plug and letting it sit.

If the paper is feeding too fast, then the first suspects are the paper encoder PCA, and the timing disc that rotates through it.

You can clean the disc with water.

Here's something I just posted in another thread:

Paper Encoder PCA Repair

You remove the board from the machine, flush the sensor with warm running water, then swish it in a bowl of distilled water.

Shake off the excess and blow it out with compressed air, I use about 60 psi.

If you don't have a compressor, then blow out as much water as you can and let it dry thoroughly.

Alternative method:

Moisten a folded paper towel and slide it in the sensor, wipe back and forth.

I cleaned one with Dull-it and a paper towel and it worked afterwards.

I've been using my methods on part number C6487-60042.

I can only get about 1 out of 3 PCA's to work after cleaning, but that gives you a 33\% chance of getting the sensor to work.

by Stephen on Feb 14, 2007 at 3:58pm Add comment
My 5550 was printing a single page just fine, then the "paper jam" message would show on the computer monitor, with no apparent jam.

Pressing the middle button (feed continue?) would spit out the page and reset the error, so that another single page could print.

I took off the top cover (two screws in the back then raise the cover and press on the two long tabs that can't be seen easily) to get to the PCA on the left. One screw and remove the electorical connector, then clean as advertised. Worked like a champ!

5100 pages and still printing... - Anonymous
Here's an email I received recently:

Printer loads paper, starts to print - maybe part of a line, pauses several seconds, prints part of a line, pauses several seconds and so on and so on.

Flashing green light throughout the ordeal. Very very very very very slow and sporadic operation.

Two hours of on-line HP Chat support did not help

My response:

Only time I've seen a problem like that replacing the black cartridge fixed it.

I assume the color cartridge could cause a similar failure.

If you have a 5550 it's easy to check, just remove the black cartridge and try with only the color cartridge installed, if that doesn't help reinstall the black and remove the color.

A 5550 will run on either or both cartridges.

And the end result:


Your suggestion worked like a charm.

In my case it was the color cartridge that was causing the problem because when I removed it, the printer operated normally except with no color.

I installed a new color cartridge and now all is OK.

Thanks for your suggestion and advice.


by Stephen on Apr 1, 2007 at 8:27pm Add comment
Just a quick note - finding this (through Google) helped me tremendously. I had exactly this problem, or rather, my parents had, and of course they called me (300 miles away) to fix the problem over the phone.

Thanks a million for posting your experiences.

- unknown
I need to open up a donated HP 5550 Deskjet to check the gears and mechanisms and circuit boards, etc.

Where are the release levels/screws?

I've tried several TAP commands but nothing turns or whirls?

No help availabls from HP.
by efinigan on Apr 16, 2007 at 4:46am Add comment
Keep the printer flat on a table while working on it, you can spill ink if you tilt a HP inkjet while working on it, your odds for not spilling are better with a 5550, but lets not take chances...

First remove the Right side cover, push down on the top of it near where it pushes against the main cover and you can see where it latches, stick a small flat bladed screwdriver at that spot and gently pry to the right while pushing down on the cover.

Take out the cleanout door and remove two screws that hold the back of the cover to the frame.

There are two plastic latches that must be released, one is accessed from the right side through the opening revealed when you took off the first cover, push the bottom of it towards the front of the printer and gently lift a little on that corner of the machine until the catch clears the hole it's been sitting in.

Repeat for the other corner, you access this latch by opening the top cover and reaching in through that area.

I solemnly swear to you that once the small cover is off only the two screws and the two latches hold the main cover on, sometimes it takes a little effort to convince the main cover to come off the machine.
by Stephen on Apr 17, 2007 at 11:19am Add comment
Thank You Stephen. After quite some time I was able to figure out how to remove the cover without damaging anything. After my success I felt kind of dumb for taking so long on a simple task

With cover off I did the best to clean my filthy service station.
I discovered that the grinding is coming from the gears around the service station. It remains in the aft position and grinds each time I apply power to the printer or hit the resume button. If I force the service station forward and apply power it moves to the rear quietly. The next time I apply power or press resume it remains in the rear and grinds. Yes both the power and resume lights are blinking simultaneously. I would certainly appreciate any expertise help you might have to offer.

Rick Farrar
Davie, Florida - Anonymous
Before following Stephen's detailled directions for removing the printer covers, I again tried to activate the Deskjet 5550.

Pressed the Power Button: Power light came on, and cartridges moved to center. No movement of any gears and no sounds (except for muttering under my breath).

Held Power Button, and Tapped Resume Button twice: nothing happened. (Same for 4 taps, and again for 8 taps.

Pressed Power Button: all three lights flashed in clockwise order several times, and everything went off for good. No sounds.

(Rubbish men will be here shortly: Should I deep-six it?

I did have trouble following Stephen's instructions: "Repeat for the other corner, you access this latch by opening the top cover and reaching in through that area"???
by efinigan on Apr 18, 2007 at 7:02am Add comment
The latches are on the front left and right, when you find the easy one on the right, then the one on the left is in a similar position. You have to open the hinged cover that gives access to the front of the printer, this is the one with the clear plastic window.

If the carriage moved to the center the machine thought the top cover was open. This could be caused by something as simple as the flag that activates the cover sensor being out of position.

Are you sure you didn't hear some motor noise before the carriage moved? It should move the service station first.

Are you saying that now the machine won't turn on? That can be a power supply problem, or a main board problem. Unplug the power supply from the machine, let it sit 30 minutes and plug it back in and try again.

There are parts on that machine that can't be bought from HP, so I wouldn't throw it out just yet, you might get to be a hero and/or make a few dollars.
by Stephen on Apr 18, 2007 at 11:14am Add comment
Success, at last, Stephen!

I followed your direction to remove the right side and top covers.

Cleaned the excess ink from the bottom of the service station (several globs the size of a pencil eraser).

When I by-passed the top cover sensor with a paper wedge under the right cover location, the Tap commands began to work properly.

When I replaced the top cover, I wedged the top cover operator into the closed (down) position as a work-around solution while I report these actions to you for further suggestions.

Unless the paper wedge comes loose, the printer works OK in my home.

Total engine page count: 6522

Error code: 00000000

T val: 250

I wonder if I should attempt to clean the service station further?
Is there a sensor there?

I guess that my principal problem was probably the Top cover sensor operator?
by efinigan on Apr 21, 2007 at 11:05am Add comment
Hey efinigan--

I've been trying to do the same thing you worked with Stephen on to clean out the old ink, dust etc from where the "home" station is for cartridge carriage and I cannot find the damn latches he refers to. Help!!! Did you go ahead and remove the service station and do all the cleaning that he recommended and did it provide any major improvements, life extension, etc.?? I got the operator station cover off with no problem and took out the two screws at the back of the printer after removing the clean out tray..the one that you remove to get out paper jams...but finding the latches are stumping me. - tashidad
If you are talking about the spot sensor, (media sensor), you can only get them from scrap machines.

If you have a spot sensor problem power on the printer and open the top cover. After the carriage stops in the center pull the power plug. Gently remove the plastic cover that is over the spot sesor. Gently wiggle the spot sensor, it is sitting on top of electrical contacts and you may be able to get a better connection. Plug in and retest.

If the spot sensor is not working try changing the media type from automatic to plain, (or whatever you are using), that is done through the driver.
by Stephen on Apr 24, 2007 at 2:11pm Add comment
I hope you will be able to help me with my problem.
My dad earlier today had a paper jam. He's not very computer savvy so I believe he just pulled out the paper from the front instead of the back.
When I first got a look at the printer the power light and resume lights were both flashing at the same time, which means a jam error, as you know. The carriage was jammed in the center and after failed attempts at printing I forced it from being jammed. It freely moved from left to right. I closed the top, tried printing again, nothing. I then put it into the Service Station, attempted printing, nothing. Now the carriage is stuck in the Service Station.
Now when I turn the printer on or press the continue button this is what happens:
-the rollers in the back spin
-3 sounds come from the little black belt with the little grooves
-the service station moves back (if I pull it forward)
-the rollers spin
-3 sounds from the black belt
-service station slightly moves
by unknown on Apr 29, 2007 at 6:51am Add comment
What is the status of the lights?

If power and resume are flashing in sync, then you hava a carriage jam.

If you have a carriage jam, and the carriage moves freely, then the lines on the encoder strip are not being read.

That would be caused by:

Encoder strip missing.

Encoder strip tension bad, caused by the spring mount on the left being out of position, or the strip is damaged. The two flanges on the left side of the mount should be behind the metal plate that the mount is screwed to.

Encoder strip dirty, gently clean with damp paper towel, wipe only from right to left, use water.

Strip not threaded through sensor. with the carriage in the center push the strip towards the back of the machine about a half inch, if the strip moves back about the same amount on the other side of the carriage the strip needs to be rethreaded.

Bad sensor on carriage board, the board would need to be replaced to fix this.

If you have to rethread the strip, or reposition the spring mount flanges it's a lot easier if you take the cover off first, instructions somewhere in this thread.
by Stephen on Apr 29, 2007 at 8:04am Add comment

My DJ5550 had the two simultainious flashing power and paper lights. Nothing from the thread looked relitive until i read about the cleaning station.

There is a fitting (flat grey plastic) which holds the ribbon to the back of the printer. This has been broken (the two feet which hold it to the printer) and it was lodged just behind the 'sled' disabling it from traveling to the right fully.

I have removed this fitting, and the printer works. We do however need to replace this fitting, so if there are any suggestions please let me know.


by wiltech on Apr 30, 2007 at 9:35am Add comment
I have a parts machine, and would happily sell you a part, but first I have to figure out what piece you are talking about.

If you need a part email me for more information, click on my name to email me, or on the crossed tolls beside it to see my profile.
by Stephen on Apr 30, 2007 at 1:29pm Add comment
The grey plastic retainer holds the trailing cables, (flat cables), to the frame.

I remounted one yesterday using two 4 inch cable ties.

Most of the 5550s I work on have a metal clip that holds the retainer on securely, but it seems that some of the early production machines do not have a clip installed.

The 5550 with the broken clip had a page count of over 24,000.

The belt on this machine was very worn, so I replaced it, unfortunately you can't get the belts anymore.

If you are working on a machine and notice a worn belt, then you can rotate it, only about 40 percent of the belt ever passes over the drive gear, so if you remove the belt and reposition it so an unworn 40 percent is now being used I think you could get a good bit of life out of a worn belt. (clean and relube the carriage rail, I relube the 5550 rail with chemplex 710 silicone based grease)
by Stephen on May 4, 2007 at 7:11am Add comment
Today I saw a couple of new codes on the configuration page, (Tap-4 test).

90020701 This printer had an obvious carriage motor failure, erratic motion, when they are like this sometimes you can get them to run long enough to get a config page. While I was attempting to get the test print the printer got an error, and all lights flickered rapidly, so I'll just think of this as a fatal error.

C0100712 This one also had all lights flickering rapidly, one of the carriage cables was pulled out of its socket on the carriage board, I unplugged power from the printer, got the cable reinserted, and that was the error code on the Tap-4 test I ran, I suspect it's a carriage board communication failure.
by Stephen on May 7, 2007 at 8:42am Add comment
Thanks very much to the many posts on this site.
It enabled me to know that there is such as thing as an encoder-strip and it is supposed to be transparent (apart from the lines). Mine was very dirty. Cleaning it with a wet tissue (from the non spring end only) made it transparent again and my printer WORKS AGAIN!!!
This has saved me £111 over sending it back to those 'people' at HP
by unknown on May 19, 2007 at 2:41am Add comment
Whenever you clean an encoder strip it's a good idea to lubricate the carriage rail.

The 5550 uses grease, but you can use a light silicone or synthetic based oil. If you use oil I would recommend adding a couple of drops once or twice a year.

If you decide to use oil then I would recommend cleaning off all the old grease.

I have been using Chemplex 710 silicone based grease on the 5550s I rebuild.

There is one other place that is greased, it is the flange that the top piece of the carriage rides on, (do not ever remove the flange from the frame, it is precisely positioned at the factory). I use Chemplex 710 on that too, I generally get hairline cuts on my fingertips when applying grease to the back side of the flange, the edge is sharp. If you do not have grease, then simply running four fingertip over the old grease to redistribute it might be good enough.

The older HP DeskJets had felt washers at the bushings the carriage rides on, these washers served two purposes, one they pushed dust to the ends of the rails keeping it out of the bushings, two, they served as a reservoir for oil.

The oil slowly seeped out relubricating the rail as the lube on the rails dried out or was soaked up by dust. The oil in the felt would keep a rail lubricated for years.
by Stephen on May 19, 2007 at 5:18am Add comment

I haven't been using my printer for awhile (ink is just so expensive)...but today, I got ink. I put it in and tell it to do a test print--that works fine.

BUT when I tell it to actually print something off of my computer it picks up the paper, pulls it to the start printing possition the ink passes over once (without laying anything down) and then it feeds the paper out and gives me a printing complete message.

What is going on? Any ideas? I just uninstalled the drivers and reinstalled them and it didn't fix it.
by unknown on Jun 1, 2007 at 8:40pm Add comment
5550 cartridges are easy to refill, I get Stratitec kits at Sam's Club.

You can find cartridge refilling instructions at:

You should also read:

And I recommend testing the printer on a different PC to make certain it's a software issue.
by Stephen on Jun 2, 2007 at 6:05am Add comment
Just put a new colour cartridge in my 5550 and the colour is not printing anything like true. Seems to be a fault with the magenta colour not picking up properly. Also, when printing black text the black is not true either but more of a browny colour! Ran the Tap 4 test and the error code shows as 90020703 (carriage blocked???). No lights are flashing and I've tried 2 different new cartridges now with exactly the same result. Helpppp please!!!!!!
by unknown on Sep 27, 2007 at 5:14am Add comment
Are the new cartridges refilled/remanufactured, or HP OEM? It's not unusual to get multiple bad refilled cartridges.

Remove the color cartridge and see if the printer will work, I suspect it's not detecting the black cartridge.

The 5550 will run in reserve mode if only one cartridge is installed, if it doesn't see the black cartridge, then it will mix the color inks to make composite black, and if you have a bad color cartridge then the composite black will be off.

Do the blot test on the color cartridge:

Remove cartridge from machine, fold a paper towel back over a couple of times so it is about 4 layers thick, shake the cartridge up and down hard, shake over a sink unless you want to clean ink off the floor.

Now blot the nozzles of the cartridge on the paper towel, you should see three colored stripes, if you don't have all three stripes the cartridge is clogged, or out of one or more colors.

If the cartridge is clogged, then soak the nozzles in warm water for a couple of minutes and try the blot test again. A little water in a saucer works fine, you only want to wet the nozzles, keep the rest of the cartridge dry.
by Stephen on Sep 27, 2007 at 8:51am Add comment
FYI - I just had the resume and power lights flashing in synch after a power outage stopped the printer during a print job. I tried re-starting the printer several times, however the printer would not re-set. After seeing this thread I decided to try to manually move the carriage to see if it could then re-set itself...Not sure if manually moving the carriage is recommended, but it worked - after moving the carriage a bit, powering down, and then powering back up the printer re-set itself :)
by Anonymous on Oct 23, 2007 at 6:54am Add comment
I have read every forum input on this, but my cartridge is still stuck just to the left center of the HP Deskjet 5550. I know better, but in a fit of frustration because of paper coming out wrinkled, I pulled, no, yanked the sheet out the front of it. At
that point - yesterday, the Status lights & power light blinked. I cannot move the cartridge manually from that spot. When I turn on the HP5550 it quietly jerks the cartridge back & forth a hair a couple of times & then the lights start blinking again. I have tried it with & w/o cartridges installed. I unplugged & replugged the power. I prayed to it & swore at it to no avail.
I tried to follow HP's instructions to "Manually release the carriage":
1. Disconnect the power cord from the printer.
2. Open the top cover.
3. Look for the gray-colored carriage on the right side of the printer. (Note: my carriage is is stuck in the center).
4. Find the horizontal (bottom) edge of the carriage and follow it towards the back (or in) until it makes a 90-degree turn. Follow it down to the ¼ inch-high, black-colored capping station. (see Figure 1).
5. Using a screwdriver or similar tool, push the capping station toward the back of the printer.
NOTE: Do not pull on the ribbon cable when moving the carriage.
6. Making sure to not push up on the carriage, move the carriage to the middle of the printer. If the carriage is still locked in place, push the capping station farther into the printer and try moving the carriage again.
7. After the carriage is pulled out from the right-hand side of the printer, remove both print cartridges and store them according to specifications.
8. Close the top cover.
I cannot find the ¼ inch-high, black-colored capping station. Please help. Thanks, Al
by AlNeocomp on Oct 24, 2007 at 11:46pm Add comment
The capping station they are talking about is the service station.

It is on the right side, and is more than 1/4 inch high.

The service station is not causing the problem.

The carriage has been angled so a piece on the inside is pushed against a metal part of the frame.

Look close, the side of the carriage towards the front of the printer is too high.

The carriage can be popped off the rail and then repositioned, but the encoder strip will then be out of place.

It may be possible to wiggle the carriage free.
by Stephen on Oct 25, 2007 at 4:48am Add comment
Thank you -- it worked. When you wrote "The carriage can be popped off the rail and then repositioned"; that gave me permission to force it, which I did. It slid back into place in the service station. The resume light then flashed & I found another input by you that I used to correct that. Now it works great. Thank you very much for your help. You are a genius!!! And never again will I ever pull a sheet out of the printer from the front!!!
Thanks, Al
by AlNeocomp on Oct 25, 2007 at 11:17am Add comment
When cleaning a SS, (service station), I remove it from the printer and take the motor off the bottom so I can get all the old ink out.

Here are the things I do to get the SS out:

Power on the printer and open the cover, after the carriage moves to the cente Pull the power plug.

Remove the printer cover.

Remove the main board.

Remove the encoder strip, (unhook the right end first).

Remove the black screw on the right end of the carriage rail.

Remove the carriage rail mounting screw on the right.

Loosen the carriage rail mounting screw on the left.

Slide the carriage to the left.

Lift the right end of the carriage rail up and sit it on the metal piece that is above it, then I put a rubber band around the rail and piece to hold it there while I take out the SS.

You have to pry and jiggle to get the SS loose, there is a piece on the bottom that must be popped out of the frame, and a guide post on the side of the SS.

Remove the motor from the SS so you can run water over the SS, see the instructions previously posted.
by Stephen on Nov 23, 2007 at 6:13pm Add comment
Stephen, Thank you so much for all of your help. After
re-reviewing several of your posts I figured out that I needed to remove the right metal housing to remove the service station.
After removing the top screw on the housing it fell into my hand and I without much effort removed the service station. I thuroughly cleaned the service station noticing that an intermediate gear that drives the roller gear was slightly worn. Took a chance on it and replaced the service station and the rest of the printer parts and housing. Now my printer works just fine thanks to your expertise. I surely appreciate your expertise help

Rick Farrar
[email protected]
Davie, Florida - Anonymous
My encoder strip came loose on the left side. How do I rethread it? Do I have to remove the whole service station to do so? Thank you for all the info you have provided here. - unknown
Cleaning ss one gear is worn out, where can I get a new one.

Error 9002070E occurs when you cannot move well cleaning station and if a pinion is bad there is no way to make that work the printer.

Thanks. - Tifon
by Stephen on Dec 11, 2007 at 4:02pm Add comment
Hi, does anyone have a good diagram of the inside of the printer cartridge holder with the parts labelled? I pulled out the printer cartridge when it was stuck and now there's some tiny plastic part that's broken off and I can see an L-shaped wire (I think this is the spring) sticking out of the back of the empty cartridge holder. I don't think anything else is damaged, but now when I replace the print cartridge and shut the cover the print cartridge fault light flashes. I know that someone on this forum suggested epoxying the spring back in place, but I'm not sure I understand exactly where the spring should go, or that I'm identifying the parts correctly. A diagram (or more explicit instructions for a beginner?) would really help! Thanks.
by mahbuban on Dec 15, 2007 at 11:12am Add comment
The 5550 Cartridge Holder, (carriage), does not have the part that breaks in the newer machines, the equivalent part never breaks in a 5550.

If you are talking about a different model, then start a new thread, or post in a thread discussing that model.

Note that I'm very careful not to mention any of those models in this post so people searching for them won't find this thread.
by Stephen on Dec 15, 2007 at 3:20pm Add comment
I am having trouble with a HP 5550. I received the message that the black ink was low so I replaced it with an HP 56, whereupon I received the message that the color ink was low after replacing the color ink with an HP 57. I received the message that the color cartridge was not compatible, I swapped it with another new one, but since then the machine prints very slowly, ie 15 minutes a page. I have followed the advice gleaned from this site and have cleaned the service station as well as I could, and tried printing with only one print cartridge installed. So far no luck.
Current error code is 90020701. Lights are behaving normally.
any ideas,
by Anonymous on Dec 16, 2007 at 11:14am Add comment
Have you cleaned the contacts in then carriage?

If you print with just the black cartridge installed what happens?

If you print with just the color cartridge installed what happens?
by Stephen on Dec 16, 2007 at 1:39pm Add comment
Yes, I cleaned the contacts and checked the inkflow from the cartridges. It makes no difference if just the black or just the color is installed, print speed is the same, very slow. But, I have only tried to print in black and white.
MC - Anonymous
Then I suspect the carriage board is failing.

Unfortunately the only way to prove it is to swap it out.

You could try reseating the flat cables that plug into the back of the carriage board.
by Stephen on Dec 16, 2007 at 5:21pm Add comment

my printer is *definitely* a deskjet 5550, and I know that my rough handling while removing the print cartridges broke off a tiny plastic part in each of the cartridge housings, leaving an L-shaped wire sticking out. Maybe I'm misdiagnosing the problem, but it seems similar to the one in the newer models, except I doubt my issue is a design fault and so no chance of getting it replaced by HP. Now when I replace the cartridges, they slot in nicely, but the print cartridge fault light starts to flash. I don't think anything else is damaged - does anyone have any suggestions? Can I glue the broken piece back in place?
by mahbuban on Dec 17, 2007 at 11:28am Add comment
The plastic part that usually breaks on the 5550s is a part of the pusher that colds the cartridges up tight against the carriage electrical contacts. It is on the bottom of the plastic part you lift to change cartridges.
by Stephen on Dec 17, 2007 at 12:56pm Add comment
Yesterday, I had a paper jam that took quite a bit of work to clear, from the back (ultimately I had to juse a table knife to pull the paper out). I am sure all the paper is out, but now the light keeps flashing and the printer just spins without taking a paper up. What can I do?
by tonic on Dec 20, 2007 at 7:48am Add comment
Remove the rear cleanout door and inspect for paper fragments. Also, clean the large rubber rollers with a cloth dampened with water.
by Bert on Dec 20, 2007 at 7:38pm Add comment
I checked and I can't see that any part of the cartridge-holder cover is broken off. And there's the issue of the wire that sticks out of the right-hand-side of each of the cartridge holders, near the back, is that normal? Is there any way I could attach a photo to my post to show exactly what's gone wrong? I forced the cartridges out when the cartridge holder was stuck on the side of the machine, rather than bringing it to the center...
by mahbuban on Dec 21, 2007 at 8:24am Add comment
Click on the crossed tools to the right of my name to send an email with attached photos.
by Bert on Dec 21, 2007 at 8:42am Add comment
Yesterday, I had a paper jam that took quite a bit of work to clear, from the back (ultimately I had to juse a table knife to pull the paper out). I am sure all the paper is out, but now the light keeps flashing and the printer just spins without taking a paper up. What can I do?
by tonic on Dec 21, 2007 at 3:08pm Add comment

You need to give us a description of the failure, not just the light is flashing, that printer has more than one light.

So please start off by powering the printer off, wait 5 seconds and turn it back on, then print a test page from the PC or the printer panel and tell us what happens.

The green light should flash for a bit, the the rollers should turn, and the inside edge of the paper will be lifted up to the rollers. You can do this with the back cover removed and watch the rollers, etc. if paper feeds it will just go straight out the back.

by Stephen on Dec 21, 2007 at 3:48pm Add comment
What does the error code 90020701 mean?
by Anonymous on Jan 8, 2008 at 10:49am Add comment

I decided it is a fatal error.

It could be caused by the carriage board, carriage cables, or the main board, or possibly by some other component, but those are the main suspects.
by Stephen on Jan 8, 2008 at 4:38pm Add comment
After 4 years of using this printer I had a paper jam that I thought was minor, it took about 2 seconds to clear. Then the same job jammed again again i cleared it (both times from the front. . . I know (now) I wasn't supposed to.
When I went to reprint, I saw that ALL 3 lights had gone out. I checked all connections, unpluged the printer for about 90 seconds, then when that did not work, turned my computer off for about 90 seconds, still nothing. The carraige is not jammed, the lid is firmly in place. I checked for loose debris that would indicated something broken - nothing. Can someone help me on this? I love my printer it has never let me down before and I print a lot.
by [email protected] on May 11, 2008 at 7:18pm Add comment
Unplug the power supply from the wall for a few minutes and then try again.

If you have no signs of life from the printer then you need to test the power supply output.
by Stephen on May 11, 2008 at 7:29pm Add comment
I received this email a few days ago:

I have a 5550 that has developed the habit lately of printing a calibration page after each print job. EVERY time!

Never had a printer do this. Any help?

My reply:

Bad ink cartridge, or possibly dirty contacts in the carriage.

Try primting with just one cartridge installed and see if it prints the page, then try with just the other installed.

Let me know the results.


And the response I got a couple of days later:

Thanks for the info.
My color cartridge had occasionally given me problems, saying something was wrong with it. I would reseat it and it would be OK for a while. But the printer was still printing a calibration page after each job.

With your information I decided to replace the color cartridge and haven't had the problem since.
by Stephen on Jul 25, 2008 at 6:50pm Add comment
I am working on a DeskJet 5550 for a neighbor, and the printer has a strange issue. The lead margins are inconsistent.

I can specify a margin in my application of .5 inches, and print a document 5 times. I will get 5 different margins ranging from .5 inches to over 3 inches.

It seems that the margin is never closer than it should be, but consistently farther.

The paper intially loads correctly, but then it advances past the carriage, and sometimes is pulled back in.

This lead me to two conclusions, but I am looking for some clarification:

1. Sensor problem - I thought that maybe the sensor on the carriage is not detecting the lead edge of the paper correctly ( what should I clean this with )

2. Rollers - I though that maybe the advancing is normal but when the paper is pulled back in the rollers are not gripping it well enough.

Any thoughts?


by spl_printers on Sep 24, 2008 at 8:07am Add comment
The sensor is not likely to cause the problem.

You can clean the rollers with water or Simple Green. - Stephen
Very recently we purchased a HP 5550dn printer. It's currently approx. 3 weeks old. The last couple of days we have been expereinceing numerous problems. ERROR 49.4018 appears quite often.
As of right now... We can't seem to print anything... :( all three lights are blinking... ): please advise.
by herbicide on Mar 5, 2009 at 12:22am Add comment
Assuming that your printer is a color laserjet, this thread discusses Deskjet 5550 issues. The only similarity to your printer is that they both print. The info below is taken directly from the Color Laserjet 5500 service manual which is essentially the the same as the 5550. The formatter mentioned is the electronics board, simply put, that is responsible for communicating Control Panel messages and interfacing with the outside world, i.e. where the cable going to your computer or network is plugged in. I suggest that you post on a Color Laserjet 5550 thread and someone with intimate knowledge of your printer may respond.

49.XXXX PRINTER ERROR To continue turn off then on

A critical firmware error has occurred that caused the processor on the formatter to abort operation. This type of error can be caused by invalid print commands, corrupt data, or invalid operations. In some cases, electrical noise in the cable can corrupt data during transmission to the printer. Other causes include poor quality parallel cables, poor connections, or home-grown applications. On rare occasions, the formatter is at fault, which is usually indicated by a 79 Service Error.

1 Press CANCEL JOB to clear the print job from the printer memory.
2 Turn the printer off and then back on.
3 Try printing a job from a different software application. If the job prints, go back to the first application and
try printing a different file. If the message appears only with a certain software application or print job, contact the software vendor for assistance.
4 If the message persists with different software applications and print jobs, disconnect all cables to the printer that connect it to the network or PC.
5 Turn the printer off.
6 Remove all memory DIMMs or third-party DIMMs from the printer.
(Do not remove the firmware DIMM in slot J1.)
7 Remove all EIO devices from the printer.
8 Turn the printer on.
9 If the error no longer exists, install each DIMM and EIO device one at a time, making sure to turn the printer
off and back on as you install each device.
10 Replace a DIMM or EIO device if you determine that it causes the error.
11 Remember to reconnect all cables that connect the printer to the network or computer.
12 If the error persists, replace the firmware DIMM.
13 Replace the formatter and calibrate the printer.
by Bert on Mar 5, 2009 at 5:43pm Add comment
Just bought a used 5550 on ebay for my mother-inlaw (she only has a parallel port) I can't get the power to ever light up. It does however do one of two things. Either the low ink lights up by itself, or the low ink and the resume light together. Neither ever flash. I popped the cover to check for problems and found the ink carriage off the rail on the left side. I manage to get the carriage back on the rail and it now moves freely from side to side, but still no power light only the above mentioned lights? Any ideas would be appreicated.
by unknown on Mar 14, 2009 at 1:41pm Add comment
The main board is probably bad.

All you can do is take off the right side cover and make sure the cables are connected.

Scroll up to find the instructions somewhere in this thread.
by Stephen on Mar 14, 2009 at 1:50pm Add comment
Talk about service, thanks Stephen. Unfortunately I've already tried unplugging and re-connecting all the cable lead I could find. Looks like I bought a DOA. Any ideas were I could find a "main board" and approx cost?
by unknown on Mar 14, 2009 at 2:08pm Add comment

Coincidence is more appropriate...

Especially since I'm a volunteer, and lately I only check the forums occasionally.

Parts are only available used, and I don't have a source.
by Stephen on Mar 14, 2009 at 2:14pm Add comment
Thanks again for the response Stephen. You seem to know the most about these 5550. I guess I'll try and find another 5550, as I had already ordered new inkers for this one.
Thanks Again
by unknown on Mar 14, 2009 at 3:08pm Add comment
The 56 & 57 Cartidges also work in the 5150 & 5650 printers.

The 5150 is USB only.

The only problem 5150's and 5650s have is that sometimes the covers are hard to shut all the way.
by Stephen on Mar 14, 2009 at 5:21pm Add comment
Wow Stephen! What an incrediable help you are to so many people - that great.
I read through your postings but didn't see this problem listed. My 5550 (with 12349 pages and one error code 90020701) prints fine but when it feeds the paper out to the tray, it doesn't feed it out quite far enough. The paper just hangs on those little guides just outside the rollers. Then the next page comes along and runs into the first one. So I have to stand right beside the printer and pull the page out the extra inch or so, so it won't jam up.

There are some exceptions, once in a while it'll feed out the second and other pages just fine. What I've tried was to unplug and reconnect, uninstall the printer and then reinstall everything. But it didn't fix it. I didn't try "the take the ink cartdrige out" trick. That seems to fix almost everything.
by L Frenchie on May 2, 2009 at 5:11pm Add comment
It's likely that the paper pusher fingers are broken off.

There are two fingers that push the paper out of the printer after printing.

If you watch as the printer goes through a feed cycle the printers start out pointing up, and they are lowered down defore paper feeds.

Removing paper jams from the front is the usual action that causes the fingers to break.

In your printer one of the fingers might still be long enough to sometimes catch the edge of the paper and push it out of the printer.
by Stephen on May 2, 2009 at 7:32pm Add comment
I tried to watch it as it printed but couldn't see the fingers that push out the paper. Maybe that's the problem - if they're broken. Where do you get new ones and how do you repair them? Is there a posting as to how to repair them?
Thank you again. - Anonymous
If you read the DeskJet 970 posts they have been repaired with strips cut from a coke can.

I have a few left somewhere in my basement, (along with about 100 HP printers).

C6487-40091 PUSHER-PAPER 3/4 BLEED

I don't think I ever posted instructions on how to replace the assembly, but it's similar to the aforementioned printer.
by Stephen on May 4, 2009 at 9:18am Add comment
I have been unable to locate the posting where you describe how to make the paper pusher fingers out of a coke can. I'm actually pretty handy with stuff like that. Could you describe how do you do it? Or direct me to another resource? Thank you soooo much. L Frenchie
by L Frenchie on May 19, 2009 at 11:00am Add comment
I have been unable to locate the posting where you describe how to make the paper pusher fingers out of a coke can. I'm actually pretty handy with stuff like that. Could you describe how do you do it? Or direct me to another resource? Thank you soooo much. L Frenchie
by L Frenchie on May 19, 2009 at 11:04am Add comment
Hi Stephen,

My 5550 prints but EXTREMELY slowly. Like one page per 5 minutes, does not matter if color or black and white. I was working fine a couple of day ago, but when I printed three 10 page articles in a row it started having this problem. I have reinstalled the drivers and everything, but no difference.

Got any ideas.

by unknown on May 29, 2009 at 8:22pm Add comment
Remove the color cartridge and try it with only the black installed, if it works that way the color cartridge is the problem.

If it still runs slow, then remove the black cartridge, reinstall the color cartridge, and test again.

Before replacing either cartridge try cleaning the contacts in the carriage, and on the failing cartridge. (use water)
by Stephen on May 30, 2009 at 4:13pm Add comment
You are a genius.

Thank you so much, I was getting completely frustrated because I could not find out what was causing this odd slow down. Turns out all I needed to do is clean the cartridges.

So cartridge cleaning be done regularly or only when such problem arises in the future?

by unknown on May 31, 2009 at 9:52am Add comment
Hi Stephen,
So many people appreciate your genius!! I wrote a couple of weeks ago - I have been unable to locate the posting when you describe how to make paper-pushers fingers for a HP Deskjet 5550 out of a coke can. Is this a joke to see just how gullible us rookies are? ;)

Could you explain how to make them or direct me to where you explained this before - ie related to your 5/4/09 posting in this thread.

Thank you again - what a help you are!!
by unknown on May 31, 2009 at 12:55pm Add comment

You do not need to clean the contacts every time.


It was another user who did the can trick.

All I recall is that he cut out pieces in the shape of the fingers, and then super glued then to the pusher bar, (on the bit that remained from the base of each broken finger).

The machine that he was working with had 3 fingers, the 5550 only has 2, I think his had one left that he used as a pattern.

You have to remove the pushers from the printer to glue the can pieces on them.


PS; You both agree with my mother, but not my wife, (about the genuis part), <g>.
by Stephen on May 31, 2009 at 2:48pm Add comment
Thanks Stephen,
I think I saw a posting somewhere that explained how to get it apart to take out the pusher bar. Thanks for your help. re genuis - obviously it's in the eye of the beholder.
by unknown on Jun 2, 2009 at 6:18am Add comment
Not anticipating an easy solution but since this thread seems like a recently used, hoping someone might step in with solution.

I have a print monitor alert not allowing me to print because "PRINTER COVER IS NOT CLOSED."

Now, earlier I had the blinking RESUME and POWER light issue but it cleared up - only problem is I think it cleared up due to a part that fell out I cannot put back because I do not know where it goes. It is about 4" long. Plastic. Gray. Part has two ends with rounded edges with holes and one side's end has more material on the upper half of said "rounded edge." The rounded edges' holes are not symmetrical. Along main body of piece one side has a lip in the middle. This whole piece was loosely attached on inner right side of printer but fell out prior to my seeing exactly where it should go. Maybe in my moving printer around to figure out blinking light problem the piece was jostled and doesn't belong where it fell from.

Any ideas welcome! I can't find schematics in my materials or online.

by unknown on Jun 19, 2009 at 2:18pm Add comment
That is the actuator for the cover closed sensor.

To reinstall it you have to remove the right side cover, that is the cover that has the operator panel on it.

When the right side cover is off you can find the cover closed sensor, it is a black sensor assembly on the logic board.

The end of the actuator with more plastic mounts near the black sensor assembly, on a nub that sticks out of the main cover, the other end of the actuator mounts on a nub that is on the right side of the opening in the main cover. When the cover closes it pushes on the actuator which rotates the "Flag" into and out of the sensor assembly.

Once you see where the actuator attaches you can figure out which way it goes in.

Cover removal procedures are in this thread, but back a bit from here.

To make it easy just click:

by Stephen on Jun 19, 2009 at 5:56pm Add comment
Thanks! I really appreciate this help and look forward to working through this process. I will update accordingly or come back with any questions if more arise, Stephen. Thanks, again!

- unknown
9002070E Service station stall

How do I fix this on a 5550 hp deskjet
by unknown on Nov 26, 2009 at 1:12pm Add comment
The first step would be to remove and clean the service station, instructions can be found in this thread.

To get there quickly:
by Stephen on Nov 26, 2009 at 2:01pm Add comment
I am a "Technology challenged" senior... If I get the "pen failure" message, does that mean I need to change the cartridge? And if so, do both the color and black cartridges need to be changed at the same time?
When you clean the cartridge, where do you clean it? Thanks.
by K. on Jan 14, 2010 at 9:54am Add comment
A pen check indicates a problem with a printhead, and the printheads on a 5550 are part of the ink cartridge.

I would first clean the electrical contacts on the cartridge and in the carriage.

I use a paper towel moistened with water, (spit works better).

Is your printer a DeskJet 5550?


Further reading:
by Stephen on Jan 14, 2010 at 10:04am Add comment
I've had the HP Deskjet 5550 for 5 years and have never gotten a "message". Also "pen failure" does not appear to be in their manual.
The 5550 automatically cleans the cartridges. If you installed the Printers Assistant on your desktop when you installed the software, click on it and when it opens look for cartridge. There will be full instructions. If you didn't install it on your desktop, go to "start", "all programs", "printer", then find Printers Assistant on the drop down box. Click on that for it to open.
Good luck, Al
by AlNeocomp on Jan 14, 2010 at 3:42pm Add comment
The 5550 cleaning routine cleans the nozzles.

The electrical contacts need to be cleaned by hand.
by Stephen on Jan 14, 2010 at 6:05pm Add comment
I have read many of your solutions written during the past 5 years, but only found one or two references to a problem with an HP 5550 identified by all 3 lights rapidly flashing (not in sync). Is this a fatal error message? What action should be taken?
- Anonymous
That is a fatal error.

Without parts all you can do is reseat the flat cables that plug into the back of the carriage board.

As I recall the carriage board was usually the cause of the fatal error, but the only way to tell was to swap it out.
by Stephen on Jan 30, 2010 at 5:43pm Add comment
I need help!! HP 5550 printer was working fine and my 1 year old pulled loose the encoder strip. Tried resetting the strip and the tension spring and cleaning the strip but think it may be damaged. In the process, we took off the carriage assembly screws and shouldn't have and spot sensor fell out and now I think the spot sensor is bad since the LED power lights don't work and I get a carriage mechanism error when trying to print--any help through this would be greatly appreciated. Can I buy these 2 parts anywhere(encoder strip and spot sensor) anywhere--HELP!!!
by jaq on Mar 27, 2010 at 4:50pm Add comment
You have to get the parts from another 5550, if you find them for sale they will probably cost more than a replacement printer.

If the spot sensor fell off while the machine was powered off, then it's probably still good.

Aren you sure the encoder strip is threaded through the sensor on the carriage board?
by Stephen on Mar 27, 2010 at 7:44pm Add comment
That is what I figured--not worth messing with--but wanted to at least try-yes--the machine was off--so what is causing the lights to not work at all?? And the carriage stops on the right hand side--on the service station--Is there something other than that sensor that would cause lights to not work?? I am pretty sure encoder is threaded right--how do I know for sure?? It seems secure--We messed with it so much I think it got a couple of bends in it (before I researched all of this valuable info and should have been more careful!!)--so is it damaged and no good?? So one of those tiny plastic films will cost as much as a new printer? How ridiculous! Any info is appreciated--you seem to be an expert in this field--thanks!
by jaq on Mar 27, 2010 at 8:32pm Add comment
I have a spare encoder strip, but do not have a spot sensor.

I have read your posts and am still not sure of your symptoms.

Whenever I have seen a printer with the panel lights all out the machine did not work at all.

How do you know that you have a carriage mechanism error?

Here is something copied from earlier in this thread:

Strip not threaded through sensor. with the carriage in the center push the strip towards the back of the machine about a half inch, if the strip moves back about the same amount on the other side of the carriage the strip needs to be rethreaded.

I use the old style view when reading posts, then I have one long list of all the posts in a thread, that makes it easier, but it is a long list of posts.
by Stephen on Mar 28, 2010 at 4:05am Add comment
There is only one little square spot in the back where the encoder strip goes through right?? I took the cover off and I have it going through there--When I plug it in it works--the carriage moves to the left, then sits there for a while and then moves back to the service station and quits there. When I send a print job through, I then get the Print Cartridge cannot move message-says check top cover for paper jam. Any ideas?? - jaq
When you turn on the printer it moves the carriage back forth, after that what operator panel lights are on?

If the ready light was on and the other lights were out, then print a test page, (Tap-4 test).

Refer to:

Post results/information/flashing lights.
by Stephen on Mar 28, 2010 at 5:20pm Add comment
None of the lights are on--that is why I figured the spot sensor must be bad?? - jaq
It does make a whirling/clicking noise when I first plug it in and then it moves back and forth, then parking on the right side. No lights come on at all--does that mean the spot sensor is bad?? - jaq
The lights on the operator panel should ripple when the printer is initializing.

Try reseating the flat cable that plugs into the back of the panel. Check the other end of the cable too.
by Stephen on Mar 30, 2010 at 4:21pm Add comment
The back of the panel where??--Do you mean the back of the printer or are you referring to somewhere inside the printer?? - jaq
What is a panel? A panel is the control unit where you turn the printer on and off, cancel a print job, or resume printing. It is easy to be located.
by deep on Mar 30, 2010 at 11:35pm Add comment
The Operator Panel is on the front right of the printer, there are three lights on it, and three buttons.

If you have removed the top cover you should have taken the operator panel off first.
by Stephen on Mar 31, 2010 at 3:56am Add comment
It is the only cable on the back of the printer, right?? If so, yes I tried that and nothing changed. No lights. Would the bad encoder strip make the lights not work or is that unrelated?? - jaq
The encoder strip is not related to the lights.

I am talking about a flat cable inside the printer.
by Stephen on Apr 1, 2010 at 4:09am Add comment
OK--got the lights to work THANKS TO YOU!!! The flat cable was disconnected--one step closer now!!--I ran the TAP 4 test got error code 90020701--the printer pulls up paper to print and then stops and the middle light blinks and says paper jam--click middle light and paper pushes through but nothing has printed--then it actually pulls another piece and prints--how do I get it to print without the first page giving an error--?? - jaq
Now you have to get the spot sensor working, that's the cause of your current problem.

Always power off the printer before working with the spot sensor.


Power on printer with cover open.

After carriage stops in the middle pull the power plug out of the printer.

Remove and reseat the spot sensor, make sure the contacts on the sensor are lined up to the contacts on the side of the carriage.


Watch closely while paper is feeding, when the carriage moves out over the paper the spot sensor should shine a light on the paper. (you can also check this before reseating the sensor assembly)
by Stephen on Apr 1, 2010 at 8:45am Add comment
OK--tried that, didn't work. No sensor light comes on--so do you think it is bad, needs to be cleaned--or something else. What about the sensor cable--could it be disconnected? I know it is tricky to get to--any ideas are appreciated. I did set driver to plain paper mode instead of automatic to bypass the problem as you suggested in another post--THANK YOU!! It does work but is noiser--is that normal?? THANKS AGAIN--you have saved the day!!! I am at least able to print again!!!!!!!!!! - jaq
The noiser might indicate that the printer needs to be lubed.

Did you wipe the carriage rail off when you were trying to get things working? The rail is greased from the factory, but you can use a synthetic oil on it.
by Stephen on Apr 1, 2010 at 1:19pm Add comment
As I recall the cable to the sensor is actually part of the plastic piece that the carriage contacts are on.

I avoid taking loose the screws that hold the carriage assembly together since that part that extends out to the spot sensor is easy to damage.

If you have it working the best thing to do might be leave it alone.

Although a few drops of synthetic lube on the rail will not hurt, (I do mean just a few drops).
by Stephen on Apr 1, 2010 at 1:32pm Add comment
The top cover and the latches are all part of the same molded piece.

What I call latches are two plastic pieces that go down from the inside of the gray cover and clip into slots on the lower part of the frame.
by Stephen on Aug 25, 2010 at 7:46pm Add comment
Thanks for this most valuable resource. My son's school project looks much better in colour and after two nights of anguish, I was about to give up and go black and white on the laser, when I finally came across this site - and there was the answer. Keep up the good work!
by unknown on Sep 9, 2010 at 3:23pm Add comment
I have a Deskjet 5550 that I have used for many,many years, it is a workhorse and despite having other printers, this is my favorite and the one I used all the time, I don't want to let it go BUT....... all of sudden it just stopped printing. The lights do not come on except for when I first plug it in... the ink light will slowly come on for a second and then there is nothing whatsoever! No power light, nothing. I tried the printer with another HP printer power cord in case the original one blew out and even with the other HP printer cord I get the same thing....nothing this fixable or it is destined for the junk yard ? :(
by Have 4 Paws on Feb 26, 2011 at 4:32pm Add comment

The top light on my 5550 won't go out. I've pushed it a million times. I've cancelled the print job on my computer. There is nothing in the queue but the light won't quit flashing. I've turned it off and on and taken the USB cable off the machine, pulled the power plug. Everything else seems to be fine but it won't print anything with this cancel print light flashing. If you are still out there, what can I do?
by SherryB on Sep 26, 2014 at 7:04am Add comment
I still have parts for this model.

Click on the crossed tools by my name to find my email, and if I don't respond try again, sometimes I miss one.
by Stephen on Sep 28, 2014 at 8:38pm Add comment
I reviewed this thread which remembers more about the printer than I do, and there is no mention of the cancel light flashing.

I checked HP's web site and they don't mention that in the list of possible patterns.

Here's the link to HP's 5550 light patterns page.

Please verify the light and repost.
by Stephen on Sep 28, 2014 at 8:50pm Add comment