Kyocera FS-1900 Service Manual page 109

The interlock circuit outputs the three different detection signals which are combined in matrix to
produce various levels of situations regarding the covers. The subsequent status is displayed on the
message display.
Top cover
N.O.
Top cover/
paper transfer
unit interlock
COM
switch (SW702)
Side cover
GND
COM
Side cover interlock
switch (SW703)
N.O.
N.C.
Ready
Close top cover
Close top cover Close paper transfer unit
Close top cover Close left cover
Close top cover Close paper transfer unit Close left cover
Close paper transfer unit Close left cover
Close paper transfer unit
Close left cover
NOTE: Message display priority is from left to right.
FS-1900
Actuator
N.C.
Top cover
switch (SW701)
Operator panel message display
Figure 4-3-12 Interlock circuit
Paper transfer unit
4-34
Engine board
+24V1
Engine
(U204)
+5V2
B
GND
+24V2
C
GND
A
GND
Output level
A B C
H L H
L H L
L H L
L H L
L H L
L L L
L L L
L L H
gate
array