How to clean oki dot matrix printer 3320 / 3321 / 5520 / 5521. oki printer service maintenance 

Thank you! This information was very useful. Did not know the printer head could be removed. Fixed my printer in less than five minutes.

You can also remove completely the printhead, instead of using grease ! To do so, unscew a little bit the bottom screw of the printhead, take the brown lever down, and unlock the metallic bar : all the printhead will be in your hands, allowing dust removal ;)

Can you tell us what spray you were using? Was it just a lubricant?