Lexmark Optra 4049 Series, Service Manual

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2-17
4049-XXX
If you do not find a cable or voltage problem replace the duplex sys-
tem board. If this does not fix the problem, replace the printer engine
board.
A 993 error indicates that communication between the printer and
duplex unit had been established but has been lost. Check the cable
as above; if the error persists replace the duplex system board.
23 Paper Jams: Examine the paper path in the duplex unit and in
the fuser exit area for paper or other obstructions. Make sure the
duplex unit is positioned correctly on the printer, and that the gear at
the bottom of the duplex unit meshes with the gear on the top of the
paper tray. Check that the paper is fed with no skew or binds from
the duplexer into the metal channel at the right edge of the tray
cover. The tray roller should move the paper forward when the tray
gear is turned, but allow the paper to be pulled by the D-roll when it
picks. Make sure the belt to the duplex DC motor is in place. Make
sure the duplex table cover (floor) is correctly snapped in place at its
front and rear and that the gear block assembly is correctly snapped
into the bottom cover. Run duplex diagnostics tests #1 and #2 to
make sure there is no slippage in the paper path. Make sure the
flags of the duplex unit input and exit sensors move freely.
While the 23 is displayed, press and hold the Return button while
pressing the second button from the top, and note the 7th and 8th
digits from the left. If they are 01 or 03, there is a problem with the
duplex input sensor signal. Remove the duplex top cover and table
cover and reinstall the duplex unit on the printer. Measure the volt-
age on J5-12 of the duplex system board; it should fluctuate from 0
to +5 VDC as you toggle the sensor. Check the sensor cable conti-
nuity. If the sensor and the cable are good, replace the duplex sys-
tem board.
If the 7th and 8th digits are 04, there is an exit sensor problem.
Remove the duplex top cover and table cover and reinstall the
duplex unit on the printer. Remove the paper tray so you can reach
the sensor. Measure the voltage on J5-8 of the duplex board; it
should fluctuate from 0 to +5 VDC as you toggle the sensor. Check
the sensor cable continuity. If the sensor and the cable are good,
replace the duplex system board.