Operation Of The Fan-Control Line - Pioneer VSX-C100 Service Manual

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7.1.3 Operation of the Fan-Control Line

1. Temperature detection of the heat sink
A
The detection is performed every 1 second by taking in the voltage of the thermistor at A/D (PORT 31).
2. Perform the following operation by detection temperature
THRMO DCT
A/D Setting Voltage
(pin 31)
0 to 0.1V
0.1V to 2.4V 5 to 122(60°C)
2.6V to 2.8V (70°C)134 -
B
2.8V to 3.4V (75°C)145 -
3.4V to 4.1V (90°C)174 -
4.0V - (110°C)204 -
• If you wish to switch FAN START from "H" to "L" and FAN MAX from "L" to "H," first set FAN START to "L," then after 100 µs, set
FAN MAX to "H."
• While "OVERHEAT" is flashing, only the POWER key is functional.
3. FAN operation
• Once the fan starts rotating, it continues to rotate at the same speed until the temperature falls to 65°C.
C
• Once the fan starts rotating, it continues to rotate for at least 20 seconds even after the temperature falls to the above-mentioned level.
4. Detection of abnormalities in the fan
• If any abnormality is detected in the fan 5 seconds after it starts rotating at high speed, and if H (abnormal) is indicated for the FANDCT
connector, "FAN STOP" is displayed for 5 seconds, then the power is turned off.
• While "FAN STOP" is displayed, AMUTE is on, and RELAY is off.
• While "FAN STOP" is displayed, only the POWER key is functional.
• While the fan is rotating at low speed, abnormality detection is not carried out.
5. Abnormality in the thermistor
If an abnormality (A/D voltage: 0.1 V or less) is detected in the thermistor, "THDCT NG" is displayed for 5 seconds, then the power is
turned off.
D
FAN Driver
E
F
56
1
2
FAN LOW FAN HIGH
(pin 51)
< 5 L
L
H
L
L
L
IC4201
PDG269A
CN305
FAN+
FAN Drive
FAN-
FAN
STOP
Q405
DTA124EK
Q404
TERMO 2SC2712(GRBL)
DTC
V+5
CN306
2
3
Note: Pin No. shows pin No. of IC4201 (PDG269A).
SP RELAY AMUTE
(pin 52) (pins 48-50) (pin 53)
L L
L H
L H
H H
H H
H L
Q406
DTA124EK
Q403
2SC2712(GRBL)
1SS355
VSX-C100-S
3
4
Display
L "THDCT NG" flashes for 5 seconds.
H
H
H
"HEAT UP" flashes for 5 seconds at 20-
H
sec intervals.
L "OVERHEAT" flashes
+12V
GNDRY
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