HP 400 - Manual (Page 77)

5-14 Problem Resolution
Clearing Paper Jams
1. Turn off the printer and remove the paper from the paper
tray. 2. Open the printer door and remove it by grasping its sides
and pulling it up.
3. Open the paper separator (the flap that separates the
printed pages from the blank sheets) by pulling it toward
you. 4. Grip the jammed paper firmly by its sides and pull it out
slowly.
5. Close the paper separator and re-attached by placing the
door flat on the paper tray. Then align the hinges on the
printer door with the pins on the printer. Press the printer
door down until the printer door clicks into place. 6. Close the printer door. Load paper and turn on the printer.