There are a few conditions in which your HP Printer Won't Print Black. Firstly, there can be an issue with the ink cartridge. It should be properly installed and have enough ink to print. Secondly, there could be some clogs or blockage in the print head. To solve this issue, the printer's built-in cleaning utility should be run. Thirdly, there can be software issues. Try resetting the printer or updating the firmware. Contact HP support team if issue remains