Oki ML1120 User Manual page 30

13. Turn the Platen Knob. If the tractor assembly is correctly
installed, the gear will turn. If the gear does not turn as
you turn the Platen Knob, repeat steps 10 to 12.
14. Replace the Input Tray and Rear Cover by fitting the Rear
Cover into the grooves at the back of the printer and
pulling gently forward until the Input Tray clips into place.
15. Replace the Access Cover.
ML1120/ML1190 User's Guide – Paper handling > 30