Panasonic KX-FP81BX Service Manual page 142

KX-FP81BX / KX-FP81CX / KX-FP82CX
When the motor suspends while it is in the receive mode (about 70~80 msec), pin 131 of ASIC IC501 becomes a low level and
Q503 turns OFF. Then Q502 also turns OFF, and instead of +24 V, +5 V is supplied through D501 so that the motor is held in place.
When the system is in the stand-by mode, all of the motor drive transistors turn OFF. Consequently, the motor current stops.
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