The Hewlett-Packard Deskjet 6122 printer has an automatic cleaning cycle for cleaning the ink cartridge print heads. Cleaning the print heads is necessary when printed pages have streaks or if they are missing lines or dots. When the printer has not been used for an extended period, the print heads can dry out and will need to be cleaned. The ink cartridges may be empty and will need to be replaced if cleaning the print heads does not solve the print quality problem. Writer Bio

HP Deskjet 6122 Cleaning Cycle Instructions - 96