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OPERATION CHECK-3
PONPING DETECTION/ THERMAL SENSOR/ CARRIER WAVEFORM
[When]
Exchange parts on Power amplifier PC board (NACLD-9283) and PC board ass'y.
[Procedure]
1. Connect the AC power cord to a wall outlet and turn on the unit.
2. Set the unit as follows.
VOLUME : MIN. , SPEAKERS : A
Ponping protect
Ponping protect
1. Check to turn off speaker relay (RL5001) after short circuiting TEST2 by resistance 27 kohms. Refer to <Fig-1>
2. Check to turn off speaker relay (RL5001) after short circuiting TEST3 by resistance 27 kohms. Refer to <Fig-1>
Thermal sensor
Thermal sensor
Check to turn off speaker relay (RL5001) after short circuiting TEST1 and GND by resistance 390 ohms.
Refer to <Fig-1>
Carrer wave
Carrer wave
Check the carrier waveform of each ch of SPEAKERS A by oscilloscope (without low pass filter).
Level is about
1.5 Vp-p
1.5 V
p-p, it is OK.
<Fig-1>
Power amplifier PC board
TEST2
GND
TEST1
(NACLD-9283)
Side-A
+
-
A-9355
TEST3
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