4. Audio is not output due to a problem in the analog circuit (Line Out, Variable Out, H/P Out)
This section details items to check if the digital audio signal is being correctly input to the MAIN PCB DAC IC [
IC508].
Check the Clock.
MAIN PCB の DAC IC[IC508
: 7pin], MASTER CLOCK 22.5792MHz or
24.576MHz
Check the Input/output voltage of +1.2V (Power supply IC for DAC)
MAIN PCB
[
IC509: 3pin]+5.0V OUT
[
IC510: 3pin]+3.3V OUT
Is the input voltage normal?
Check the power supply voltage.
MAIN PCB
[
Q549] collector terminal: 12.0V (design standard value) Within ±
1V.
[
Q547] collector terminal: -12.0V (design standard value) Within ±
1V.
Is the power supply voltage abnormal?
Check the signal.
MAIN PCB[
R839] MUTE
Is the level "
Hi"?
(If "
Lo" is displayed, output is muted for Line, Variable and H/P.)
Check each part listed after "
YES" in "
Check each part listed after "
1.4. I2C Communication Line Abnor-
".
The MCU is malfunctioning or latched.
Check the Clock.
FPGA[IC501] と PLD[U501]
[R590] : PCM-MCLK/DBCK, [R585] : PLD_DACI_MCK
Replace the MAIN PCB if repair of single parts proves too compli-
cated.
Check each part listed after "
YES" in "
".
YES
NO
NO
YES
NO
YES
NO
YES
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
43