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ACSI Refill Instructions
HP 51640A, HP 51645A, HP 51645G, and HP 51650A Cartridges

Also HP C6615A Cartridges.

HP Deskjet 700, 800, 1000, 1200, and 1600 Series Printers and DesignJet Plotters

Updated May 13, 1999


These cartridges are virtually identical and refill the same. The ink in these cartridges is retained because the cartridge develops a slight vacuum. These cartridges are sealed plastic boxes.


We offer a selection of 3 inks for these cartridges.
  • WJ-1010 is a premium pigmented ink which is an extremely close match to the performance of the original HP ink. This ink will give excellent Ultra-violet resistance to fading, and good water resistance. A word of caution: Because the pigments tend to carbonize in the print head if printing continues with a dry cartridge, it is important to refill immediately when using this ink. This ink is also more expensive than the other two inks.
  • WJ-163 is a dye-based ink which is also an excellent performance match to the original HP ink under most conditions. This ink is oriented toward text printing and drys quickly, leaving the dye on top of the paper. Thus, it tends to be less water-resistant than the other two inks, but offers excellent text printing. It also tends to sit on top of color inks and will sometimes smudge when printed on an ink background.
  • WJ-138 is a dye-based ink which was developed to provide better graphics performance than WJ-163. Because it drys a bit slower, it will tend to blend into color graphics and soak deeper into the paper, smudging less. However, it will give slightly inferior text-on-white-paper performance than WJ-163 since the WJ-138 tends to spread more before drying. WJ-138 also gives good water-resistance because more of the ink has soaked deeper into the paper.
Having said all of this, what do we recommend?

Most people will find that WJ-163 is the best choice for their general purpose printing. If you require professional quality output, a high degree of fading protection, or a water resistant ink, consider the WJ-1010. If you print lots of graphics, particularly with black text on a printed background, consider WJ-138.

Unless you otherwise specify when ordering, we will ship WJ-163 ink.


Step 1) Put the cartridge on some paper towels in an area where you can tolerate a spill. Be sure that you are wearing old clothes, since the first time you fill the cartridge, you will probably get some ink on your clothes and hands. You may wish to wear rubber gloves if you don't wish to stain your hands. We also don't recommend refilling as a family project -- it's amazing what a three-year-old can do with a pint bottle of highly concentrated ink! See our General Information for more details.

Step 2) Turn the cartridge upside down.

  • Locate the rectangular copper printhead where the ink comes out.
  • Behind the printhead is a black plastic rectangular well.
  • Behind the rectangular well is a round black dimple in the center of the cartridge bottom.This round black dimple looks similar to a mold release mark from the plastic mold. In reality, this dimple is a small piece of black rubbery plastic which conceals the original fill hole of the cartridge!

Step 3) Remove the black dimple plug over the fill hole. You may need to scrape it off with a knife or screwdriver.

Step 4) Push the ball in the fill hole into the cartridge with a ball point pen or similar device. Forget about it.

Step 5) Inject 30 ml (one syringe bottle) of the ink into the fill hole slowly. You may add an additional 5 ml if the cartridge will take it. Fill to the bottom of the fill hole.

Step 6) Now you must seal the fill hole air tight. We suggest using silicon rubber, hot glue, or (preferred) a 10-32 x 1/2 inch long (M6) set screw. (Stainless steel is preferred for longer life, but regular steel will do. These set screws should cost you 25 cents or so at the local hardware or home center store.) The set screw will self-tap and form an excellent plug which can be removed and re-installed each time you refill. Do not use a screw with a round or flat head! Only use a set screw so that this can be recessed below the surface of the cartridge.

Whichever you decide to use, you should squeeze and hold the cartridge just before sealing to set up the vacuum. Make sure the seal is flush or just below the cartridge surface.

Step 7) After sealing, release the sides of the cartridge and squeeze again, twice. A couple of drops of ink should come out of the printhead.

Step 8) You might wish to set the cartridge over a paper towel for an hour as a drip precaution. Expect a few drips until the vacuum stabilizes. Before inserting the cartridge, blot off the hanging drop of ink with a paper towel.

Step 9) When inserting the cartridge, first tilt the cartridge so that the ball is caught above the set screw and doesn't roll into the area above the print head, where it can occasionally block off some ink flow.

Step 10) Immediately run the printhead cleaning software. (Go to the HP software and select "Services".)


There are several problems which can occur with this cartridge.

Incorrectly Installed Cartridge

Occasionally you will receive a message which indicates that you have incorrectly installed your cartridge, or that the cartridge is bad. Try the following steps to correct this error.
  1. Remove and re-install the cartridge. Be sure to put the cartridge completely back into the slot before lowering the lever.
  2. Check the copper pads on the back of the cartridge for problems.
    • Ink buildup -- Remove with tissue and warm water. Do not use cleaning sprays. Dry before re-inserting.
    • Holes in the copper pads. Occasionally, a hole will be punched in one of the copper pads. If this is your problem, the cartridge is damaged beyond repair and needs to be replaced.
    • If these problems have been checked and the problem persists, take a stiff, dry paper towel and buff the pads to remove oxidation buildup.
  3. If the problem persists, unplug the printer. Then, check the pins which are in the printer and normally touch the copper pads on the cartridge. Look for obvious problems such as bent pins, debris, or ink build up. Buff the tips of the copper pins gently with a stiff, dry paper towel. Re-insert the cartridge and plug in the printer. Try printing again.
  4. If all else fails, you may have a bad cartridge. Occasionally, the cartridge fails internally if printing is attempted when dry.

Cartridge doesn't Print

Follow the instructions below for cleaning the printhead.

Cartridge prints in Streaks or Bands

Follow the instructions below for cleaning the printhead.

Skips on Horizontal Lines

This cartridge has an interesting and slightly annoying problem which develops in about 50 percent of the cartridges on only the first time they are refilled. The symptom goes as follows:

When printing long horizontal lines, the printer prints for a couple of inches (5 cm) and then skips an inch or so (2 to 3 cm). Then the printer resumes printing the line. The problem only occurs on black lines and only occurs the first time the cartridge has been refilled.

This problem is caused because of two things which come together in this cartridge:

  1. The original HP ink has a tendency to foam.
  2. There is a tiny filter located just above the printhead, which traps a small bit of air when the cartridge is refilled.
These two problems combine to cause a bit of foaming between the filter and the printhead when the cartridge is refilled the first time. This foam blocks the ink flow to the printhead, and on long prints which pull a considerable volume of ink -- such as long horizontal black lines -- the flow of ink to the printhead can be temporarily cut off.

Our WJ163 and WJ138 inks for this cartridge have had anti-foaming agents added to reduce and eliminate this problem. However, the presence of 5 to 10 percent remaining HP ink when the cartridge is first refilled is enough to trigger the problem. But all reports are that the problem disappears with the second refill of the cartridge, probably because the original HP ink has been flushed out of the cartridge.

Be aware of this problem and recognize that the problem will resolve itself.

To Clean the Printhead

Clean the printhead only if the cartridge doesn't print or prints in streaks.
  1. Follow the directions in the printer manual.
  2. Locate your printer software and select Printer Services. Then run the printhead cleaning software.
  3. If that doesn't work, here's a quick and easy method to try next:
    • Turn on the hot water faucet and let the water get good and hot.
    • Stick just the copper printhead under the hot water for 3 to 5 seconds.
    • Remove the printhead and dry with a tissue.
    • Re-insert in the printer and run the printhead cleaning routine.
    • Print 2 pages. You should get dilute print for a half page or so and then good quality printing.
  4. If this doesn't work, soak only the printhead in simmering water for up to 2 hours. You may add up to 50 percent ammonia for tough clogs. But don't do this if you haven't run the printhead cleaning software first.

To Clean Your Sink

The ink is water-soluble. Use plenty of soap and warm water. You may also need to use Comet or a similar cleaner if the stains persist.

To Clean Your Hands

On hands, the best substance to use is Ink Be GoneTM, a specially developed hand cleaner available from ACSI Bulk Inks. (To place an order, Click Here.)

To Place An Ink Order

You can telephone us at 1-888-728-2465 (USA Tollfree) or 1+740-374-9949. You can also Order Online or by other ways including by Fax, or by Postal Mail, or by EMAIL.

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Copyright 1999, Automation Consulting & Supply, Inc.
Contact us at 1-304-622-5086 or email us at Order Email.
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