Marantz ND8006, Руководство по обслуживанию

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4. Audio PCB Abnormalities and no Audio Output (Line Out, Variable Out, H/P Out)
This section details items to check if the digital audio signal is being correctly input to the Audio PCB DAC IC [ U1019 ].
Is the Master Clock waveform indicated below being input to the Audio PCB DAC IC [ U1019: 7 pin ] in
the function indicated below?
DSD playback (USB-B, NETWORK Module) : 80.000MHz[
U1016
]
PCM playback (USB-B, NETWORK Module, and Fs352.8kHz or more) : 80.000MHz[ U1016 ]
PCM playback (OPT1/2,COAX, and Fs44.1kHz system) : 45.1584MHz[
U1001
]
PCM playback (OPT1/2,COAX, and Fs48kHz system) : 49.152MHz[ U1003 ]
Check the voltage of the DAC power supply IC. AUDIO PCB
Is the input voltage normal?
[ U1007 ]+5.25V OUT
[
U1026
]+3.3V OUT
[ U1027 ]+3.3V OUT
[
U1028
]+1.3V OUT
Check the power supply voltage. AUDIO PCB
Is the power supply voltage abnormal?
[
Q1033
] Emitter terminal: 12.8 V (design standard value) Within ±
1V.
[
Q1034
] Emitter terminal: -12.8V (design standard value) Within ±
1V.
Does the logic level of the Audio PCB [
U1012: 7 pin
] Mute signal
turn to " Hi "?
If the [
U1012: 7 pin
] Mute signal is "
Lo
", then the line, variable and
H/P outputs are muted.
Use a soldering iron to replace the Fuse [ F1001 ] or the Audio PCB.
Check each part listed after " YES " in " 1.3. Power Supply Voltage
Abnormalities ".
Check each part listed after " 1.4. I2C Communication Line Abnor-
malities ".
The System uCOM is malfunctioning or latched.
Check if the Clock output from the crystal oscillator [ U1001, U1003 and U1016 ] output terminals
corresponds with the table to the left.
If output is stopped, check that power is being input to each crystal oscillator power supply input [ 4pin ].
Replace any crystal oscillator exhibiting an abnormality or the Audio PCB.
If there is an abnormality in the power supply, check for abnormalities in [ U1007, U1026, U1027 or
U1028
].
[ U1007 ]+5.25V OUT, [ U1026 ]+3.3V OUT, [ U1027 ]+3.3V OUT, [ U1028 ]+1.3V OUT
Is the FUSE [ F1001 ] blown out?
Check each part listed after " YES " in " 1.3. Power Supply Voltage Abnormalities ".
Check the power supply voltage. AUDIO PCB
Is the voltage abnormal?
[
D1005
] Cathode : +18V ± 3V,
[ D1007 ] Anode : -18V ± 3V
Check that the voltages of [ C1088 : + terminal] and [ C1089 : - terminal] are 14.4 ± 1V and -14.4V ± 1V, respectively.
If there is an abnormality, replace the Zener diode [
D1046, D1023, D1047, D1024
].
If there are no abnormalities, it is likely that there is a [ Q1033 or Q1034 ] malfunction.
Replace the [
Q1033, Q1034
].
Does the logic level of the Audio PCB [ U1012: 2 pin ] turn to " Hi "
with the [
7 pin
]?
YES
NO
NO
YES
NO
NO
NO
NO
YES
YES
NO
YES
YES
YES
If there are no abnormalities in the Audio PCB [ U1012: 1 pin or 8 pin ] 3.3V power supply voltages, there is an isolator IC [ U1012 ] malfunc-
tion.
Replace [ U1012 ] or the Audio PCB.
Before Servicing
This Unit
Electrical
Mechanical
Repair Information
Updating
52