A computer printer is a device that receives text or images from a computer and prints them onto a piece of paper. There are two types of printers; impact printers and non-impact printers. Impact printers physically print the material directly onto the paper via ink cartridges. Non-impact printers use a different technology to print the material [source: Britannica]. Here we are going to look at impact printing. The ink in your ink cartridge won't last forever, and you have to know when it needs replacing. Every printer is different. Some printers will give you advance warning by having a TONER LOW or INK LOW light flash, while with others you'll just notice the quality of the print starts to look faded. In either case, it's time to get a new cartridge. Although the basic process is the same for all impact printers, some of the details differ slightly from printer to printer. Always check your printer's user manual for exact instructions regarding how to replace your ink cartridge. Here is how to change the ink cartridges on a HP 4100 series Officejet printer.

  1. Check that the printer is turned on.
  2. Locate and open the cartridge access door, which is on the right side of the printer. When the door is opened, the cartridge carriage will move to the right for easier access.
  3. Press down on the old cartridges in order to release them from the carriage, and remove them.
  4. Take the new cartridges out of the packaging and remove the protective tape. Make sure you don't touch the gold colored contacts.
  5. Hold the cartridges with the printed label facing up. Slide one cartridge at a time into the print carriage and press them into position. They should snap into place easily. If they don't, they're not properly aligned. The black ink cartridge goes on the right and the color cartridge goes on the left.
  6. Close the cartridge access door [source: HP].