There are a couple different approaches to cleaning a printhead, depending on what type of inkjet printer you have. There are two types of inkjet printheads you should be aware of, an integrated printhead and a printhead that is built into the printer.
An integrated printhead is a printhead that is built into the ink cartridge itself. These printheads are considered disposable printheads as they are disposed along with the used ink cartridge when the ink cartridge is replaced. Cartridges with integrated printheads usually more expensive than a cartridge that doesn’t have an integrated printhead.
For cartridges that are ink tanks the printhead is separate from the ink tank itself. The printhead may be permanently installed in the printer itself or can be a replaceable maintenance item. Ink tanks are generally less expensive than ink cartridges with the printhead integrated. With the printheads separated the colors can also be split into individual ink tanks allowing only the color that is depleted to be replaced rather than the entire cartridge as in the case of a tri-color cartridge.
First, try a printhead cleaning:
Most printers have a built in cleaning function that you can find under the settings or tools section of your printer's display screen. This is the easiest way to solve a clogged printhead problem. Consult your printer’s manual to run the appropriate cleaning function, the cleaning process generally takes a couple of minutes.
For this HP Officejet 8015 printer, the "Clean Printhead" option is under the "Printer Maintenance" menu of the display screen:
Once it is completed, print a diagnostic page or printer quality report. For the HP Officejet 8015 printer, the "Print Quality Report" option is under the "Reports" menu of the display screen.
If the test pattern is crisp, you are ready to print! If the quality is still poor, let the printer sit for about 10 minutes before running a second cleaning, this allows the ink to soak on the printhead. It might take a couple of cleanings to get a cartridge properly primed, especially if the printer has been sitting for a while.
If your printer uses cartridges with an integrated printhead, you can also try the “paper towel method”:
Take a warm damp paper towel or coffee filter and blot the cartridge with the print heads facing down onto the paper towel to remove the dried ink on the print head. Then, taking a DRY paper towel or coffee filter, hold the cartridge down against the paper towel for 2-3 minutes. A dry paper towel will wick the ink out. Do not wipe the print head as this may cause damage.