Lexmark C752 Service Manual page 149

Step Action and questions
3 Check the joint switch cable connection to CN19 on the
finisher system board.
Is the cable installed correctly?
4 Check the joint switch activating spring for any signs of
damage.
Is the switch activating spring broken?
5 Check the joint switch for correct operation. The switch
can be checked by measuring continuity while
actuating the switch.
Is the switch operating correctly?
6 Check continuity of the joint switch cable.
Is there continuity?
Finisher is inoperative, or not recognized
This problem can be caused by a problem with the autoconnect system between the finisher and the printer. It
also can be caused by a problem with the power system in the finisher.
Step Action and questions
1 Check the AC line cord to the finisher to make sure the
options and printer are connected properly.
Are the printer and options AC line cords connected
properly?
2 Make sure the communications cable from the finisher
to the printer is installed correctly at the output options
autoconnect on the printer.
Is the cable installed correctly?
3
Disconnect the autoconnect cable from J2 on the
system board. Check the resistance between J2-6 and
J2-7 on the cable connector. The resistance measures
between 45 ohms and 50 ohms.
Is the resistance correct?
4 Make sure the communications cable is connected
properly to CN3 on the LVPS relay board.
Is the cable installed correctly?
Note: The relay on the relay board is connected to
+5 V dc from the printer through the communications
cable. When the printer is powered on, +5 V dc is sent
to the finisher relay board relay coil which energizes
the relay and connects primary AC line voltage to the
LVPS.
5 Check the resistance of the relay coil by measuring
between CN3-1 and CN3-2 on the relay board. The
resistance measures between 45 ohms and 50 ohms.
Is the resistance correct?
Yes No
Go to step 4 Install the cable
correctly
Replace the joint Go to step 5
switch assembly
Go to step 6 Replace the joint
switch assembly
Replace the Replace the
finisher system cable
board
Yes No
Go to step 2 Connect the
printer and
options correctly
Go to step 3 Install the cable
correctly
Go to step 6 Go to step 4
Go to step 5 Install the cable
correctly
Replace the Replace the relay
communication board/LVPS
cable assembly
Diagnostic information
5060-2XX
2-115