Pioneer SC-LX90 Service Manual page 96

5
No audio output from the Preout connector (Assys)
Failure in the D/A converter
Failure in the
A/D converter or
1 Input a PCM signal (signal from a
its periphery
CD, etc.) to COAX.
2 Set the listening mode to Pure Direct
No further
diagnosis is (PCM Direct).
3 Set the signal switch to Auto or PCM.
possible in this
state.
After the above settings are completed,
are signals output from FD, BCK, and
LRCK on the DIGI BRIDGE Assy?
NG
Check if the DIGI BRIDGE Assy is
properly connected. (Is a pin bent and/or
short-circuited?)
NG
Failure in circuits (selector,
Poor connection
etc.) on the path from
of connectors or
the DIR to the DIGI
improper repair
BRIDGE Assy
work
Is ±15-V power output from the OP amp, which is
located at the stage after the DAC?
OK
Failure in the DAC or
its peripheral circuits
5
6
Failure in the digital small-signal system block
OK
Check if sound is output when the "SRC" audio parameter
is set to OFF.
OK
Is power to the DAC (V + 3DA and V + 5DA) output?
OK
Poor connection of connectors
on the path of power supply
SC-09TX
6
7
Failure in the Failure in the DIR
DSP
If audio signals are input to the
No further COAX, OPT, and FRONT OPT
diagnosis is connectors, is sound of those
possible in this signals output?
state.
NG
Failure in the DIR
or its peripheral
circuits
NG
Failure in the regulator for V + 5DA
or the power-supply block connected
to that regulator
NG
7
8
OK
Failure in circuits
(selector, etc.) on the
path from the input
connector, with which
no sound output is
available, to the DIR
OK
Failure in an oscillation circuit in
the periphery of the X1001, or
the SRC or its peripheral circuits
NG
8
A
B
C
D
E
F
41