Sometimes printer rollers are failing to pickup a piece of paper or worse yet they are causing a paper jam. You can easily clean the rollers using only a coffee filter and either distilled or purified drinking water. Just lightly dampen the coffee filter with the water and rub the wet damp filter on the roller.
Clean printer rollers with a coffee filter
Previous post: Lego WeDo Software Activity Tab Blank (Flash Fix)
Next post: Clean LCD monitors cheaply