|May be time for a more drastic printhead cleaning method if the blockage is very bad. Cleaning it using the maintenance section of the printer software may not be sufficient.|
Remove the printhead and leave it to soak overnight in warm, soapy water, then rinse in clean water and leave to dry before replacing it.
If that doesn't work it's time to buy a new printer.
To avoid a repeat of the problem, make sure you use the printer at least every other day to print an image which uses all the ink colours.