HP 3500 - Manual (Page 235)

8. Align the formatter door in the tracks at the bottom of the slot, and turn the screw to
attach the formatter board to the printer.
9. Replace the DIMM access door by inserting the tabs on the door into the slots on the
printer. Swing the door shut.
10. Reconnect the power cable and USB/parallel cable.
ENWW Installing memory and font DIMMs 223