HP LaserJet 3020 All-in-One Printer - Manual (Page 127)

8. Lower the green lever.
9. Reinstall the cleanout part by inserting it as shown. Push down on the two tabs until the
part snaps into place. Install the cleanout part correctly, because future jamming might
occur if the cleanout part is not replaced correctly.
10. Close the ADF lid and replace the ADF input tray.
ENWW Media jams occur in the automatic document feeder (ADF) 117