If your printer will not print black on your document then there are a couple of possible issues that might need resolving. First of all has the printer given a warning about low ink or has the ink actually run out and need replacing? If so, then replace the ink cartridge as directed. It’s a myth that you don’t need black ink to print a colour image or indeed that you can print black text without the printer requiring a colour cartridge. The majority of printers require both the black and colour ink cartridges to be recognised as having ink and will not operate if one of the colours is out of ink.
If you have just installed your ink cartridges correctly and there are no error messages relating to the cartridges, but the black ink is still not showing when you print a document then the issue may be a blocked print head. The first step in checking this out is to go to the printer maintenance facility and run a test print to see if there is a trace of black printing at all. You can access this procedure in a couple of ways, either go to your printer icon at the bottom of your screen and select printer utility > maintenance > clean heads or go to file print and select printer utility > maintenance > clean heads. Performing a head cleaning procedure will force ink from the ink cartridge through the print head and clear any blockage that may be preventing the printing of the document. It’s important to remember that each time you perform a head cleaning procedure you print a test page to monitor the improvement of the print quality. The printer is clever enough to know that if you decide to perform another head cleaning procedure after printing a test page that the blockage was not cleared and will force a greater amount of ink through in a further attempt to clear the blockage. Although you may have no real option but to see it through, the downside of performing several head cleaning procedures is that it uses a lot of ink and will drain the ink cartridge quite fast.
The head cleaning will usually clear up the issue of the black cartridge not printing but if it’s still the case that the printer will not print black or the quality will not improve it’s possible that the print heads in the printer are the issue. Depending on the original cost of the printer it may be more economical to replace the printer than try to have the print head replaced.