This likely applies to other model numbers of this finisher as well. After a changed staple cartridge SC 745 showed. Found the bracket that holds the Stack Feed Out Belt HP Sensor was bent just enough to not allow the pawl to actuate the sensor in the home position. Carefully bent the bracket back and it resolved the issue. It appears as if the staple housing unit made contact with the bracket most likely during the staple cartridge swap but possibly during the print run when stalple cartridge emptied.. Hopefully this will save someone else some time in troubleshooting as the motor and sensor tested ok. Next step was to replace the board had I not noticed the bent bracket.
John
Senior Service Engineer
DPS
John
Senior Service Engineer
DPS