The recovery blade is a thin Mylar strip which rests against the length of the drum, a small thin blade located next to the Wiper Blade, which guides waste toner into waste bin. The waste toner scraped clean by the wiper blade falls downward toward the recovery blade, which scoops it into the waste bin.
If the recovery blade is rippled, bowed, nicked or scratched, or missing, the toner that is scraped from the drum by the wiper blade will fall onto the paper. The amount of damage to the recovery blade will determine the amount of toner that will drop on to the page. It could be anything from light peppered dots to dark heaps or chunks.