2.1.3. Preout / Subwoofer out
Check Power Supply Voltages for Preout.
MAIN PCB
[IC1901] : 4pin -9V
[IC1901] : 8pin +9V
Check the PWM waveform of the PWM Modulator.
MAIN PCB
-Preout
[IC1701] : 26(CH0_REF0), 23(CH0_REF1), 22(CH0_REF2) / Lch
10(CH1_REF0), 13(CH1_REF1), 14(CH1_REF2) / Rch
Square wave of approximately 3.3V p-p
-Subwoofer out
[IC1701] : 107(CH7_REF0), 110(CH7_REF1), 111(CH7_REF2) pin
Square wave of approximately 3.3V p-p
Check of Audio output
MAIN PCB
-Preout
Check the Audio signal output from [C1908](L) or [C1918](R).
-Subwoofer out
Check the Audio signal output from [C1990].
Check the MUTE circuit.
MAIN PCB
-Preout
Check that the Audio signal is not muted in [Q1901], [Q1902](Lch)
and [Q1911], [Q1912](Rch).
-Subwoofer out
Check that the Audio signal is not muted in [Q1981] and [Q1982]
Check Reset signal for PWM Modulator [IC1701].
MAIN PCB
[IC1701] : 63pin RESET = "Hi"
Check Clock for PWM Modulator [IC1701].
MAIN PCB
[IC1701] : 154pin MCK_IN = 108MHz
Check Control signal for PWM Modulator [IC1701].
MAIN PCB
[IC1701] : 71(SPI_CK), 72(SPI_CS), 73(SPI_DATA) pin
Check the soldering or replace the device or SMPS.
SMPS PCB
➡ MAIN PCB
[CN1002] 5pin -9V ➡ [Q1003] : -9V
[CN1002] 3pin +9V ➡ [Q1001] : +9V
Check the soldering or replace the device.
[IC1701] : 26, 23, 22, 10, 13, 14 pin
[IC1701] : 107, 110, 111 pin
Check the soldering or replace the device.
[IC1901]
[IC1981]
Check the soldering or replace the device.
[Q1901], [Q1902], [Q1911], [Q1912]
[Q1981], [Q1982]
Check the soldering or replace the device.
[IC1701] : 63pin, [R1715], [IC1201] : 77pin, [R1231]
[IC1701] : 154pin, [OSC1701] : 3pin
[IC1701] : 71, 72, 73pin, [R1726], [R1725], [R1723]
[IC1201] : 83(CSR_SPI_CK), 79(CSR_SPI_CS), 82(CSR_SPI_DI)pin
[R1243], [R1239], [R1242]
OK
OK
OK
OK
OK
NG
NG
NG
NG
NG
END
No faults
Identify the input function from which sound is not output or from which noise occurs, and then check the troubleshooting sec-
tions from 2.2 onwards.
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