Removing and reinstalling cartridges often works. You can even unplug the power cord from the back of the printer when it is turned on and the power cord from the outlet to reset it. Wait 15-20 seconds before reconnecting the cables and turning on the printer. You may also need to replace the cartridge, or you may also need to replace the printhead. This was all about “hp printer problems on mac” If nothing else works, you can schedule an appointment to have your problems repaired.