If the printer suddenly does not print a specific color, look at the print head.
There are several reasons why an inkjet printer suddenly no longer prints a certain color – often it is the color black. This is often the case if you have not used the printer for a long time and the pushbutton has dried up. However, it can also be located on the printer itself, since it did not move the cartridge carriage into the rest position correctly when it was switched off – ink residues dry and block the outlet. Also, a location near a heat source such as a heating promotes drying. Unfortunately it does not help to use a new (original) cartridge. Finally, the fault does not lie on the cartridge.
In such a case you should first use the integrated print head cleaning, up to three times! In addition, it is useful to reorient the print heads. If these measures do not help, remove the print head and inspect the contacts on the bottom. Clean this and the counterpart in the carriage with a fiber-free cloth.
If your printer still refuses to print the appropriate color, give the printhead a small bath. To do this, distilled water is sufficient: Place the print head with the lower side (ie with the contacts) in a deep plate or support and fill some of the water into the vessel. As a rule, a height of 5 millimeters is sufficient, in any case, the contacts should be in the water. After a few hours, all the colors should have dissolved. Make sure the print head is completely dry before replacing it.
If you want to use something harder, you can also try using propyl alcohol. This is also available as a spray with a target tube, in order to use it specifically. It is best to perform cleaning over a small bowl or something similar to catch the remains. Again, make sure that the print head is completely dry before installing it in the printer. As a rule, it should then also work again with an impeccable pressure. Otherwise you only have the options to buy a new printhead or printer.