Sharp AR-651 Service Handbook page 243

[CC1] Abnormal Saddle stitcher microswitch
[Procedure 1]
Is the switch actuator for the inlet door working properly?
NO
Fix the mechanism.
YES
Is the inlet cover switch (MS1S) working normally?
NO
Replace the switch.
YES
Measure the voltage of J10-8 on the saddle stitcher controller PC board when the inlet door is open.
Is it 5V?
NO
The inlet cover sensor (PI9S) is broken. Replace it.
YES
Measure the voltage between J19-2 (+) and J19-1 (-) on the saddle stitcher controller PC board. Is it
24 V?
NO
Replace the saddle stitcher controller PC board.
YES
Check the wiring between J19 on the finisher controller PC board and J1 on the saddle stitcher
controller PC board. If there is no problem, replace the saddle stitcher controller PC board.
5 - 93 AR-651/810 TROUBLE SHOOTING