HP 51641, C1823, C6625 and C6578, No. 78, 17 Cartridges

Step 1) Put the cartridge on some paper towels or newspapers in an area where you can tolerate a spill.

Step 2) Look at the top of the cartridge. You will notice three entry points with plugs in them. These are vent holes and cannot be sealed after refilling.

Step 3) Push the plugs into the cartridge with a ball point pen or similar device. They will fall inside and remain on top of the sponge. Typically, the colors are as illustrated in the photo below. However, to be sure of which color is in each chamber, insert a toothpick and check the color of the ink on the toothpick when it is withdrawn. .

Step 4) Be sure to remove the protective snout from the syringe before attaching needle. Insert the needle fully into the holes, angling toward the print head on the bottom of the cartridge and reaching all the way to the bottom. HOWEVER, FOR THE MAGENTA, WHICH IS THE CENTER HOLE ,DO NOT PUT THE NEEDLE ALL THE WAY TO THE BOTTOM. YOU CAN DAMAGE THE PRINT HEAD AND RUIN THE CARTRIDGE. Insert all but 3/4-inch of the needle into the middle hole. (See photo on right) W e suggest that you tape over the other two holes while filling to avoid accidental color contamination. Go slowly or you will develop air bubbles in the lower part of the sponge which will block ink flow.

Step 5) The holes on top must be open during printing. You may tape them over for storage, or to keep the ink from evaporating, but you must pierce a tiny hole over each one or the cartridge will print a few pages and then "airlock."

If you get poor quality print or no print at all you probably have clogged jets. Dried out cartridges are notorious for getting clogged up. The following is the best way to deal with this.

Take the cartridge out of the printer and take some toilet paper and wad it up over the print head (that's the thing on the bottom of the cartridge where the ink comes out). While standing, hold the cartridge in your hand, with the print head toward the floor and swing it hard, like a softball pitcher winding up for the pitch. On the down swing really put some force into it. The force of gravity on the ink will force it through the clogged jet and clean it out. Swing two or three good swings and look at your tissue paper. When you see all three colors coming out and leaving a good rectangular "track" you have gotten it unclogged. Re-insert the cartridge into the printer. Run the normal cleaning routine a few times. If this doesn't work, soak only the print head in ammonia, or alcohol for up to 2 hours. Then reinstall and run cleaning cycle again. If all the colors come out by swinging the cartridge, but it still won’t print one or more of the colors, it is very likely you have a defective cartridge. Some of the resistors may be burnt out. Burnt-out resistors are caused most of the time by continuing to print after one or more colors have gone dry. The ink is the cooling agent for the resistors and when it is gone they overheat very quickly.

Another very effective method for clearing clogged print heads is to use a can of compressed air. Simply insert the stem of the nozzle (that comes taped to the side of your can of air) in the hole on top of the cartridge where you put the ink in. Give 2-4 short bursts of air and then look at your tissue to see if the ink is coming out well.   WARNING!!! THIS CAN BE VERY VERY MESSY! You should either be outside or over your bathroom sink. In either case you better have a LOT of tissue around the print head to catch the ink. If you put too much pressure on it the ink will come out the top also, so GO EASY.