Cooling Fan Confirmation; Fan Failure Sensor Confirmation; Temperature Sensor Confirmation; Fan Catching A Foreign Body Sensor Confirmation - Marantz SR-14EX Service Manual

4. Cooling fan confirmation

4.1 Fan failure sensor confirmation

1) Set to be SPK output 1W from the front channel.
2) Connect the 1pin (LOCK) of the connecter JN10 (on P754) to chassis (GND level) by a wire.
3) After 6 seconds the SPK relay works, and the SPK output isn't output.

4.2 Temperature sensor confirmation

1) Connect a resistor (470ohms 1W) between JN10 3pin (T-2CH) and DC +12Voltages.
2) Confirm the cooling fan starts working. (Status : JN09 between 1pin and 2pin = +7.5Voltage, Fan speed = Low)
3) Remove the resistor.
4) Confirm the cooling fan stops.
5) Connect the resistor between JN10 4pin (T-3CH) and DC +12Voltage.
6) Confirm the cooling fan starts working again.
7) Remove the resistor.
8) Confirm the cooling fan stops.
9) Connect the resistor between JN10 3pin (T-2CH) and DC +12Voltage. And then connect another resistor between JN10
4pin (T-3CH) and DC +12Voltage.
10) Confirm the cooling fan starts working.
11) And then connect the resistor between JN10 2pin (SPEED) and DC +12Voltage.
12) Confirm the cooling fan changes to work with high speed. (Status : JN09 between 1pin and 2pin = +11.5Voltage, Fan
speed = High)

4.3 Fan catching a foreign body sensor confirmation

1) Connect the resistor (470ohms 1W) between JN10 3pin (T-3CH) and DC +12Voltage.
2) Confirm the cooling fan starts working. (Status : JN09 between 1pin and 2pin=+7.5Voltage, Fan speed = Low)
3) Set to be SPK output 1W from the front channel.
4) Hold the cooling fan by hand and stop it.
Notes: Take care of wound in the hand!
5) After 6 seconds the SPK relay works and the SPK output isn't output.
JP03
RT73
JT13
C-CH
SL-CH
WA300J101
P754
JP04
IDLING
RP43
RP73
FRONT
R774
J714
SR-CH
WA300J102
TOP
FR-CH
IDLING
RP44
RP74
70
J713
R773
FL-CH
P704