Denon PMA-50, Service Manual

Page: 35 / 93

Check the PWM waveform output of PWM Modulator by Oscilloscope.
AMP PCB
[IC9006] : 5pin (Lch)
[IC9005] : 5pin (Lch)
[IC9011] : 5pin (Rch)
[IC9011] : 5pin (Rch)
Check the square waveform of the terminals. If an approximate
5V
P-P
square wave can be confirmed at each terminal, there are no
problems with DIR (PCM9211) and the PWM Modulator (CSRA6601).
No faults
Identify the input function from which sound is not output or from
which noise occurs, and check the troubleshooting sections from
2.3
onwards.
2.1.A
PWM waveform (square wave) is not output. Fault in the
DIR (PCM9211) or PWM Modulator (CSRA6601).
Check
“2.2. COMMON (Power, Contorl signal line)”
,
and check the soldering or replace each devicce if there
are no faults.
[IC204] on MAIN PCB.
[IC903] on AMP PCB.
2.1.B
PWM waveform (square wave) is disrupted.
Fault in output stage circuti.
Check the soldering. If the fault still occurs check
"2.1.A". .
NG
NG
OK
2. No Sound, Noise generated
2.1. COMMON(signal)
Check Digital Audio Data output from DIR.
MAIN PCB
[IC204] : 17, 18, 19, 20pin
DIR_LRCK, DIR_BCK, DIR_DATA, DIR_MCK
OK
Check the soldering or replace each device.
[IC204] : 17, 18, 19, 20pin on MAIN PCB.
NG
Check Digital Audio Data input for PWM Modulator.
AMP PCB
[IC903] : 80, 82, 81pin
WS, SCK, SD
OK
Check the soldering or replace each device.
[IC903] : 80, 82, 81pin on AMP PCB.
NG
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