Cooling Fan - Onkyo HT-RC660(B) Service Manual

OPERATION CHECK-10

COOLING FAN

Circuit
e.g.(TX-NR636)
Thermal sensor
Q6300
Power amp.
Condition to operate
OFF
LOW
THERMAL
MID
HIGH
THERMAL(Temparature of thermal sensor)
-30
Shut down
immediately
VOLH(Voltage of VOLH port)
0V 0.35V 0.4V
OFF
Hysteresis control
How to check
1. How to check operation of Cooling Fan.
See "CONFIRMATION OF COOLING FAN OPERATION" in OPERATION CHECK-4.
2. How to check the value of THERMAL and VOLH.
See "CONFIRMATION OF OUTPUT VOLTAGE AND THERMAL SENSOR" in OPERATION CHECK-1.
TX-NR636/ 737/ 838/ HT-RC660/ HT-R993/ DTR-30.6/ 40.6/ 50.6
THERMAL
138
Q7009
MPU
(Main Microprocessor)
VOLH
140
Normal/ Bi-Amp
OFF or
LOW MID
Headphone
STOP STOP STOP
LOW LOW LOW
LOW MID MID
MID HIGH HIGH
52 60 63 65
OFF LOW
Hysteresis control
1.9V 2.0V 2.2V 2.3V
LOW MID
Value D/A output of the MPU
OFF 0V
LOW 1.7V
MID 2.2V
HIGH 2.5V
FANCTRL
3
VOLH
Powerd Zone-2,3,4
OFF or
HIGH
LOW
Headphone
STOP STOP STOP
LOW LOW LOW
MID MID MID
HIGH HIGH HIGH
67
MID HIGH
3.3V
HIGH
COOLING FAN
Fan drive
Q8701,
Q8711
MID HIGH
STOP STOP
LOW LOW
MID MID
HIGH HIGH
95 100
Shut down in
Shut down
10 minutes
immediately
continuously