Panasonic KX-FC971CX-S Service Manual page 151

8.5.4. HOOK SWITCH (SW500)
When the handset is lifted, the switch turns ON, and the signal at pin 19 of IC10 becomes low.
When the handset is returned, the switch turns OFF, and the signal at pin 19 of IC10 becomes high.
ON-Hook
OFF-Hook
8.5.5. JAM SENSOR (SW502)
The JAM sensor is a detection switch for determining whether the recording paper edge is in the correct position or not. If the
recording paper cannot be detected correctly at the JAM sensor position even when recording paper is present, then JAM is
displayed. If the recording paper is at the sensor position, then the switch turns on the IC10-119pin switches to a high level.
Digital Board
SW
OFF
ON
Analog Board
Signal (IC10-119 Pin)
Paper Low level
No paper High level
151
Signal
High level (IC10-19 pin)
Low level
KX-FC971CX-S / KX-FGA521CX-S