There could be several reasons that trigger the HP printer not printing problem. The most common of them all are an empty ink cartridge, an outdated printer driver, or using a bad quality page. In order to fix it, you must take a few troubleshooting steps like replacing the ink cartridges with a new one and updating printer drivers from the HP support website. You must also cross-check the quality of pages that you are printing on. HP has also an in-built app known as HP print and scan doctor that you can download on your system and choose the option Fix Printing option. In case you are not able to fix it, you must get in touch with the printer experts.