Cleaning HP Ink Carts

[Trigger 37]

I have begun working on HP printers and I have learned alot since I started this. Before I had only been envolved with Canon and a couple of Epson printers. Since HP is trying to take over the universe of printers, I felt I had to at least begin to understand their products. It is amazing just how much you can learn if you are willing to get your hands dirty and get down into the guts of the machine. It became a necessity for me since someone gave me 12 HP DeskJet printers.

To cut down the length of this story, i've become very confident in the disassembly and repair of quite a few HP DeskJets. They are actually very basic machines. The design point is so different from Canon and Epson it took awhile to understand the differences. While I have only started I've learned a great deal about HP printers, and because I was a Development Engineer I have the skill to see into their design philosophy. To understand product you have to know about the 4 Division of any Corporation. They are; Senior Management, Marketing, Manufactuering, and Development. These are four forces pulling decisions in 4 directions. Management always makes the final decision, but they are driven first by Marketing. If you can't sell it, no one cares how well it is designed or manufactured. Engineers want nothing but to take pride in building the best mouse trap. Manfuacturering takes pride in producing it for the lowest possible cost. Marketing takes credit for the total number of sales, and Managememt only cares how much money it makes. It is a very rare product that satisfies all four of these at once.

I will expand on this subject in future post, but for now I will get to the meat. In fixing a lot of the older Deskjet printers, I've need to refill a lot of the HP 23 and 45 ink carts. These are rather large ink jet carts with integrated printheads. The HP 45 Black ink cart is large and holds a whopping 42 ml of black pigment ink. The HP 23 is even bigger but it is a tri-color ink cart but still holds 10+ml of each ink color. The HP 45 is not a sponge fill ink cart, at least the ones I have. It has a "Green" flag indicator on the front of the cart which is probably nothing more that an floating flag inside the ink cart. When the cart is full, the green flag is flying. When it is about empty it gradually turns to black. The HP 23 Tri-Color has no such indicator.

I had quite a few of these ink carts and most of them would not print any kind of decent nozzle test. The stanard cleaning for these ink carts is to wet a paper towel and to blot the printhead on the towel and attempt to dissolve any dried up ink inside. This has never worked on a dried up ink cart. Some people have gone so far as to soak the printhead into 1/4" of water but this turns out to be a serious mistake. This can work wonders for a "Black" HP 45 but can destroy a HP-23. The answer is that soaking a HP-23 will cause the 3 colors to "Wick" together in the water and contaminate the other colors back up inside the printhead. Once the Cyan or Magenta ink floods the water, the resultant color will wick bach up into all colors. You can't stop it. Cyan seems to be more prodomanent and contaminates the Magenta and Yellow. Once the ink colors are mixed the ink cart is dead.

Well I'm not finished with this post but I've had too much Red wine tonight so I have to sign off. I'll try and finish the story tomorrow night.

 

[mikling]

With the 23 and 78, watch out for weak nozzle plates that become separated and literally fall out.
Then when refilling, it is easy to cross contaminate when overfilling so watch out!
To clean these cartridges after cross contamination, you will need a centrifuge. Don't use a priming tool..you'll be sorry.
Now you will learn the perils of a high capacity sponge and its ability to hold bubbles and lock up the cartridge.
Finally, to refill the 78 properly you will need a deep vacuum chamber. If you use a priming tool, you'll just end up in a spiral.

These cartridges garnered a nice reputation for remanufactured cartridges......NOT.

You ain't a refiller until you can refill a 78 consistently that is working from full to empty with no ink flow problems ! It's one of the ultimate challenges in refilling. The proper finished weight for a properly refilled 78 is 130 grams.

You'll need a few bottles of wine so don't finish them too quickly!

The 45 is however easy easy easy.

To clean out the waste ink on one of these HPs printers I held it under the tap and literally washed out the waste ink area without disassembling the complete printer! They're tough and designed to be a true workhorse! That was then.

 

[Trigger 37]

mike,...Thanks for the information about the HP 78. I just checked my inventory and I obly have 2 printers thast use the 78, and they are the in the 900 series. I have not touched them yet. Right now I'm working on ink carts for the OfficeJet 2610xi, which is the HP 94,95,96,97. The OfficeJet printers seem to be very sensitive about changing ink carts. I keep getting the "Check the Cartridge" error, and I'm not sure if this is really bad connections at the gold dimples or just that it thinks this is a refilled ink cart and is rejecting it. I switched to some old ink carts and got it to settle down but these need refilling worse than the ones that were in there and they are a different model number.

Anyway back to what this thread was supposed to be all about. As you mentioned, filling the HP-23 and 45 is really simple. But if there is a hard clog in those carts, then you have fill up a lot of ink that you can't get out. It is easy to soak any "Black" cart because it is not going to contaminate anything but black. Yet it will wick some water back up into the black ink but not enough to do any damage.

The real problem comes with the color ink carts. You can blot them on a hot wet paper towel but you can't soak them. Because I have many of these ink carts, I wanted to experiment with them and see if I could clear the cogged up printheads before I refilled them. When they are virtually empty you can blot them all day long on a hot wet paper towel and get nowhere. So I decided to try a different approach. Everyone know how much more effective HOT WATER is in disolving clogs, so I heated a small cup of distilled water so it was about the maximum you could put your finger in. I did not want to get it so hot that I would damage the printhead or the syringe. I injected about 5-6 ml into a clogged cart that was virtually empty. Withing a few minutes I was albe to get a couple of color patterns on a blot to a wet hot paper towel. Once I got all colors to show up, I installed it back in the printer and did some cleaning cycles and some test prints. Soon the ink cart was printing decent colors and showing the clog was getting dissolved. Then I started printing the 3 color bar chart that Neil has made available. At first I was only printed this in a limited size (3x5 Photo) until I confirmed it would continue to supply the ink. Of course the colors were faded from all the water but that is what I wanted. I'm sure the viscosity of the left over ink in the sponge and the hot water was much lower that what it should have been. You could tell by the wetness of the printed paper that the colors were more water than ink

I then had to print larger pages to purge all the watered down ink out of this ink cart. I finally decided to remove any excess water/ink mix with a syringe. Once I had it low enough, I refilled the ink carts, did some cleaning cycles, and then printed all the nozzle test pages that HP uses. They came out about 99.5 percent, as one color had one nozzle that was firing but was not printing where is should have been. Anyway it seems good enough for what I want to do.

Of course this is only one test, but it worked on one other black ink cart also. I'm heading off on vacation for about 3 weeks so I won't be doing much posting or experimenting. I have had good luck refilling HP ink carts that were not empty, and some luck with those that were really dried out. All of this was on the HP 23, and HP 45, as you say these are the easy carts.

I am now working on the HP 94,95,96,97 series. I just did a HP 95 tri-color, that would not print anyting and by weight was next to empty. I only injected 2-3 ml of hot water into each of the colors and now I have Magenta and Yellow printing after a couple of cleaning cycles. The Cyan still will not show a drop. The water I used was not as hot as before. These ink carts will set in the printer and we will see what happens in the morning.

I was in Stapes today and checked the price of many HP ink carts. I can't believe people will pay that kind of money for a 3 color ink cart, especially the way that HP printers waste ink. HP is basically charging $2.00 per ml. Canon is charging about $1.00 per ml.

People would ask, "Why do you waste so much time trying to rescue an old HP ink cart". My answer is "I have more time than money, and it is just one part of understand everything I need to know about printer, and inkjet technology" I have 28 HP printers I have to repair. Some are in good condition, some are broken, some have ink, some don't have AC adapters. What I am beginning to learn about HP does not impress me. Has anyone ever checked out how many different printer models that HP has put out over the last 5-8 years. It must be in the 100's. It seems when they design a printer, test it, and bring it to the market, it only stays in production until the customer complaints or problems become a burden to the company. Then they modify the design to fix the problem and obsolete the old printer. The don't seem to high enough production volume to get the economy of scale, and maybe this is why they don't sell parts,... they don't have any to sell. All of their subcontractors are too busy tooling up to make the next parts for the next printer.

I also can't believe how terrible they operate and the amount of noise they make, no matter what they are doing. If I didn't know any better, I would think there is a blacksmith in there turning hand made gears to feed paper and three monkeys on roller skates sliding back and forth with tiny paint brushes. The thing I hate the worst is their Service station and the fact that they clean all colors at once and dump a lot of ink. The Service Station seems to be the one thing they carry from printer to printer and if you've ever taken one apart, there is nothing there to really do any cleaning of the printhead. It is basically a place to force the printhead to dump ink, as I don't see any mechanism to "Suck ink". There are pads where the printhead sets, one for black and one for color, but unless there is a "Hidden Bellows" action, there is nothing else. Possible the lower gear "Rotates" but I don't see how it sucks. I had a very old printer and the Service station was full of black gummed up Pigment ink, but the color pad looked virtually new and there was no colored ink spots on it anywhere. Clearly it wasn't cleaning anything.

I'm sure I will learn more about these printers,

 

[mikling]

One reason why HP has so many different models is that they have carefully determined their channels to the consumer and tailored the same basic machine with multiple numbers or change different features ever so slightly and call it something else. That way, the consumer thinks he is buying a different printer for a different price. HP are masters at marketing inkjet printers and the others are learning from them....like Canon. I have noticed that in the last year Canon has released so many more printers with their integrated cartridges and looks to have shrunken the range of separate ink tank printers or relegated them to much higher price points. In truth the separate ink tank economy aspect never did catch on with the general consumer even though it makes sense. It is much easier to play the printer game of selling at a loss and make the profits on the cartridges with integrated head cartridges to the general consumer as HP has shown. HP remains the gorilla in the inkjet printer market....and that's what top of mind will do for their brand.

 

[Manuchau]

I would suggest that for all HP carts, you buy a bottom filler. ALL HP carts can be filled from the bottom, and this cheap tool also can be used to suck out a few ccs if the cart is overfilled.

You can also buy ones for the 23, 17, 41, 78 etc that will let you suck some ink out from the bottom. Often, this is enough to open the nozzles.
Most important with HP colour carts is to purge air out of them after refilling...

Keep us posted. It takes a while to learn how to do these consistently well...

 

[Trigger 37]

Manuchau,... thanks for the tip. I've been aware of the bottom fillers and suppected that they also sucked ink out but I just could not see how this would work on 3 color ink carts. The alignment to a given bank of nozzles has to be extremely good, otherwise you would totally contaminate the ink.

If you can explain how it works I would greatly welcome any new knowledge.

 

[gfreed]

Lots of folks are saying that by using a suction device you can clear clogs as well as air from the jets. I've also tried all the various soaking methods with unsatisfactory results. Well I've found another way to clear the jets that is easy the far less time consuming, messy and expensive. I wish there was a way to attach a picture so I can show you this thing. What I've done is to take a hypo syringe and substituted the needle with a hole size reducer so that the syringe nozzle fits the fill hole in the cartridge. I then pressurize one of the Hp 57 tanks holding the pressure for a couple of seconds. I hold the pressure long enough to get one drip or two drips. The nice thing about this is that I can choose what color I need to mess with instead of sucking on all the colors wasting ink and making a big mess. I also don't need one of those expensive rubber cartridge suckers! I've done this a couple of times and it seems to work good for me every time. Only bad thing is you need to do this over the sink with the water running or you can really have a mess. I got dripped on once and the that was the end of those cloths. Talk about getting back to the 60's! That shirt has a real tie dyed look to it after attempting to get the ink spot out.

 

[websnail]

This is the first time I've heard of bottom filling or suction devices for HP printheads and I'm really keen to locate something like this for the HP88 printheads.

Anyone seen anything that fits the bill?

 

[gfreed]

Ok so you want to "SUCK" on your print head! You can either go out and pay an outrageous $85 for a Cartridge Vacuum device or you can do the following:

Build a little box just bigger then the Cartridge. Doesn't have to be as long as the cart but needs to be wide enough.

Make a little 1/4 inch spacer that completely covers the head.

Fill in any gaps between the spacer and the head with caulking compound so there is a smooth transition between the spacer and the head face.

Take some tooth picks and glue them to the head spacer so that when you place the cartridge in the BOX the cartridge head is about 1/4 or more
from the bottom of the box.

Take some more tooth pick and glue them around the cartridge to that the cartridge is suspended in the middle of the box.

Now spray the cartridge and the box interior liberally with MOLD RELEASE. You can get this at any hobby store.

When the mold release dries place the Cartridge back in the box. Now fill the box with MOLDING RUBBER(FIRM SETTING).
Its usually a two part compound you mix up in a cup and you can pour it. Again you can get Molding Rubber and any hobby store.

Once the rubber dries remove the box either by breaking it or whatever. Drill a little hole at the bottom of the mold just hitting the head spacer.

Now using a big syringe that snuggly fits the hole you just drilled shoot water up into the hole pressurizing the assembly. Shoot water all around
where the cartridge meets the rubber. Remove the rubber mold from the cartridge.

Now you have a rubber mold of the cartridge. Slip another cartridge loaded with ink into the mold. Place the syringe in the hole at the bottom of
of the mold. Being that this Cartridge doesn't have a head spacer there will be a little void where the spacer used to be. When you pull back on
the syringe plunger the void becomes a vacuum "SUCKING" ink into the 1/4 inch void.

This little vacuum device will work for both black ink carts and color carts too. One other thing remember those tooth picks? You might have to fill
the holes left when you remove the picks. Use glue, clear caulk, what ever sealant works.

OK!

 

[Trigger 37]

Websnail,... I've check and can find no mention of the HP 88 ink cart. Anyway, Atlanticinkjet.com sells priming tools and bottom refill tools for most HP ink carts.