Anyone who has ever owned an inkjet printer knows how expensive replacement ink cartridges can be. In fact the price of a single set of replacement cartridges can easily exceed the original purchase price of the printer. That is why many printer owners choose to save money by refilling their old ink cartridges instead of buying new ones. If your printer uses the popular HP78 tricolour cartridge it is important to refill the cartridge properly.
Remove the HP78 cartridge from the printer before it is completely empty. It is much easier to refill the cartridge when it is not completely dry.
Fill a small container with isopropyl alcohol and sit the cartridge in the container so that the alcohol covers the print head. This step may not be necessary if the ink cartridge is not completely dry, but if one or more of the colours is completely out of ink, this alcohol soak is important. Allow the cartridge to sit in the alcohol overnight; this will loosen any dried ink.
Sit the print cartridge so that the label is facing up and the metal connector is facing you. Locate the three small holes in the top of the cartridge. As you face the cartridge, the right hole is the cyan (blue) ink, the middle one is magenta (red) and the left one is yellow.
Insert a ballpoint pen into each hole to push the plug in, then use a needle to widen the hole. Fill the syringe from your refill kit with 5cc of the appropriate colour ink, then carefully insert the syringe into the filler hole. After each colour has been refilled, carefully cover the hole with a small piece of tape.