AR-FN2 (serv.man10). ARFN2 Service Manual-Circuit Descriptions - Sharp Copying Equipment Service Manual (repair manual). Page 9

SSW is the micro switch for release a paper jam in the paper transport path. 
This switch is connected with +24V. By opening the open/close section, the contact is opened and this switch actuates as a safety switch. It is
connected in series to CSW. 
When the switch is ON, +24V is applied to the cathode of ZD1 and the base current is supplied to Q5 to turn on Q5, inputting the open/close signal
to the CPU (IC 9-17 pin). 
C2 and C9 are used to absorb noises. R57 is the pull-up resistor. Logic of signals inputted to the CPU: Cover open 

®

 H, Cover close 

®

 L

CSW is the switch of the cover which is opened and closed when replacing staplers. 
This switch is connected with –24V. When the open/close section is opened, the contact is opened and this switch actuates as a safety switch. It is
connected in series to SSW.
When the switch is ON, +24V is applied to the cathode of ZD2 and the base current is supplied to Q4 to turn on Q4, inputting the open/close signal
to the CPU (IC 9-16 pin). 
C1 is used to absorb noises. R58 is the pull-up resistor. 
Logic of signals inputted to the CPU: Cover open 

®

 H, Cover close 

®

 L

Set switch input circuit

Cover switch input circuit

Set switch
(SSW)

Cover switch
(CSW)

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