Issue description
Defects appear when performing a staple. The LED is in blue and indicate the stapler, customer inserts the stack of paper, no staple happens. If customer open the staple access door, and LED will turn to red, if customer close the door, the LED will turn to blue again, but no staple happens if customer insert paper for stapling. The root cause of this issue is due to massive paper dust collected at staple throat blocking the paper‑in‑sensor, this makes the stapler believe paper already exists and won’t staple the next sheet.