Lexmark 4227-X00 - Manual (Page 60)

Diagnostic Aids 3-3
4227-X00
Interface Selection (4227-100)
Serial or parallel attachment can be selected from the user menu
under Interface Options. If serial attachment is selected, RS-232 or
RS-422 can be selected with the switch that is accessible through
the rear cover. Serial attachment parameters are set in the Interface
Options menu.
Operation with the Top Cover Removed
After removing the top cover, the printer can be operated for service
purposes by positioning the cover near the main logic board and
reconnecting the operator panel cable. The ribbon cover must be in
place on the top cover. Or, remove the operator panel and cable,
jumper the two pins of the ribbon cover sensor connector CN1
together on the back of the panel, and reconnect the operator panel
flex cable to the main logic board.
Note: Printing without the top cover affects print quality and may
cause paper jams since the upper feed rollers on the ribbon cover do
not help restrain and feed paper.