Onkyo TX-NR545 Service Manual page 80

1
About Cooling Fan
Cooling Fan
E.g. (TX-NR646)
D
Thermal sensor
Q6300
Power
Amp.
C
Condition to operate
LOW
THERMAL
HIGH
B
THERMAL (Temperature of thermal sensor)
-30℃
Shut down
OFF
immediately
VOLH (Voltage of VOLH port)
0V 0.35V 0.4V
A
OFF
Hysteresis control
1
2
THERMAL
138
Main Microprocessor
Q7009
VOLH
140
VOLH
OFF or
LOW
Headphone
OFF STOP STOP
LOW LOW
MID LOW MID
HIGH HIGH
45℃ 50℃ 52℃ 55℃
LOW
Hysteresis control
1.9V 2.0V 2.2V
LOW MID
2
3
Value D/A output of Main Microprocessor
OFF
LOW
MID
HIGH
FANCTRL
3
MID HIGH
STOP STOP
LOW LOW
MID MID
HIGH HIGH
63℃ 65℃ 95℃
Shut down in
MID HIGH
continuously
2.3V 3.3V
HIGH
3
4 5
0V
2.0V
2.7V
3.3V
Fan driver
Q8710
Cooling Fan
Q8711
Q8714
100℃
Shut down
10 minutes
immediately
4 5
6
Appendix
D
C
B
A
TX-NR545/646/747
DTR-20.7/30.7/40.7
6