HP C4480 Incompatible Print Ink Cartridge Fix

There are 2 ways to fix this, and either one is super easy. If just leaving the cartridges out for a few minutes and them putting them back in doesn&work you can always reset the checksum by doing the following... 1: Press &and the power button at the same time. It will display "Enter Special Key Combo" 2: In Order Press Blue, Green and then Grey 3: Press 'OK' 4: Press the blue button until you see "checksum for relock data input" 5: Press &twice (the first time will display a number) 6: Press X three times. 7: Presto! Start printing with your "incompatible ink"