HP LaserJet Enterprise flow M830 Multifunction Printer series - Manual (Page 166)

4. Press on the door next to the document-feeder
rollers to make sure it is closed completely.
5. Lift the document feeder input tray.
6. Squeeze inward on the two slots at each end of
the e-Duplex assembly.
156 Chapter 9 Solve problems ENWW