Remanufactured Ink Cartridge Replacement for HP 45 HP 78 (2 Black 1 Color 3 Pack) one year guarantee Note: if unable to print using the cartridge, please refer the below information for the reason and troubleshooting steps: Reason 1: The cartridge contacts are not making a firm connecting with the printer contacts. This happens if the unit is not installed properly or if the cartridge contacts and printer contacts are dirty. Please make sure that both of the contact points are clean and that the cartridge is installed firmly. Reason 2: The printer may need to be reset. To reset a printer please follow these instructions. 1. Remove the cartridges out of the printer and shut printer off. 2. Unplug printer from the power outlet and your computer as well. 3. Turn off the computer as well 4. Wait a few minutes before turning on your printer. 5. Turn your computer on (if turned off). 6. Plug in the printer to the outlet and to computer as well. 7. Turn the printer on and wait until it starts up. 8. Install the printer cartridges, and if alignment page does not print out automatically, try doing it manually. The reset of the printer should allow the printer to read the new cartridge.