Pioneer SC-LX75 - Page 44

35
SC-57
5
6 7 8
5
6 7 8
A
B
C
D
E
F
No Sound
Head Phone
Speaker Front ch
Speaker
(Front ch is OK)
Pre OUT Front ch
Diagnose MIC HP ASSY
(arround JA3476)
or replace MIC HP ASSY
Yes
No
No
Analog in (e.g CD)
Pure Direct 
Pre out sound
Yes
Check A-DAC BRIDGE ASSY
CN3794,3793 21,23 pin Signal
(FL OUT, FR OUT)
Diagnose AUDIO ASSY
Go to flow [A]
Diagnose or replace
IR POWER AMP ASSY
No
No
No
Yes
No
No
Yes
Yes
Diagnose DAC HIGH ASSY
(DA part is NG) Go to flow [B]
Yes
Zone2 Audio No
output (MAIN is OK)
Analog in output
from Zone 2 line
Yes
No
Digital inoutput
from Zone 2 line out?
No
Yes
No
Check MIC HP ASSY
CN3472 1 or 3 pin
(HP OUTPUT SIGNAL)
Yes
Check CONNECTORS and FFCs
MIC HPF-IN BRIDGE
INTERFACEFB CONNECT
FRONT BRIDGEAUDIO ASSY
No Problem /
No Damage
No
Diagnose AUDIO ASSY
(circuits arround IC2801)
or replace AUDIO ASSY
Analog Input
Digital Input
INPUT ?
Change to
"Auto Surround"
Pre OUT Front ch
A-DAC BRIDGE ASSY
CN3794,3793 25,27 pin Signal
D-DAC BRIDGE ASSY
CN3781 20,23,24,27 pin
Clock,Data
D-DAC BRIDGE ASSY
CN3781 3,9,10,12 pin Clock,Data
Diagnose or replace
DIGITAL MAIN ASSY
D-DAC BRIDGE ASSY
CN3781 5 pin Clock
Yes
Pre OUT Front ch
Signal
No
Yes
AUDIO ASSY
CN3051 10,14 pin Signal
Yes
No
Check the signal path of
FL OUT,FR OUT in AUDIO
ASSY or replace AUDIO ASSY
Pre OUT
(Front ch is OK)
A-DAC BRIDGE ASSY
CN3794,3793
5,7,9,11,13,15,17 pin Signal
Yes
No
D-DAC BRIDGE ASSY
CN3781 20,23,24,28,29,30 pin
Clock,Data
Yes
No
Pre OUT of C, SL, SR,
SBL, SBR, FHL or FHR
OK?
No
Yes
AUDIO ASSY
CN3051 2,4,6,8,12,
16,18 pin Signal
Yes
No
A-DAC BRIDGE ASSY
CN3794,3793 1,3 pin Signal
D-DAC BRIDGE ASSY
CN3781 14,15,16,18 pin
Clock,Data
Yes
No
Zone3 Audio No output
(MAIN is OK)
IR BUFFER ASSY
CN6803 18,23 pin Signal
Diagnose or replace
IR BUFFER ASSY
No
Yes
IR BUFFER ASSY
CN6802 6,11,16,21 pin,
CN6803 3,8,13 pin Signal
No
Yes
When headphone is
connected,speaker
relays turn off
(hear relay click sound)
Yes
No
Check MIC HP ASSY
CN3472 7 pin(XHPDET)
When headphone is
connected +3.3V0V
Diagnose MIC HP ASSY
(arround Q3451)
or replace MIC HP ASSY
Check CONNECTORS and FFCs
MIC HPF-IN BRIDGE
INTERFACEFB CONNECT
FRONT BRIDGEAUDIO
D-AUDIO BRIDGEDIGITAL MAIN ASSY
No Problem /
No Damage
No
Yes
Diagnose or replace
DIGITAL MAIN ASSY
Diagnose or replace
DIGITAL MAIN ASSY
Check the signal path of
audio output signals in AUDIO
ASSY or replace AUDIO ASSY
Diagnose or replace
IR POWER AMP ASSY
Diagnose or replace
IR BUFFER ASSY
Diagnose DAC HIGH ASSY
(AD or DIR part is NG)
Go to flow [B]
Check the audio signal in AUDIO ASSY
(CN2502 5,7,9,11,13,15,17 pin
IC2501orIC3273(IC3221)
IC2751,IC3151,IC3201,IC3251,IC3271,
IC3272Preout terminals)
or replace AUDIO ASSY
Check the audio signal in AUDIO ASSY
(Selected input terminalIC2501
CN2502 25,27 pin) or replace AUDIO ASSY
Diagnose DAC HIGH ASSY
(DA part is NG) Go to flow [B]
Check the audio signal in AUDIO ASSY
(CN2502 21,23 pin IC2702IC2501
IC3101JA3101)
or replace AUDIO ASSY
Check the audio signal in AUDIO ASSY
(IC2501 34,35pin
JA2951 Zone2 OUT terminal)
or replace AUDIO ASSY
Check the audio signal in AUDIO ASSY
(CN2502 1,3pinIC2501)
or replace AUDIO ASSY
Diagnose DAC HIGH ASSY
(DA part is NG) Go to flow [B]
Diagnose or replace
DIGITAL MAIN ASSY
Check the audio signal in AUDIO ASSY
(IC2501 77,78 pin
JA2951 Zone3 OUT terminal)
or replace AUDIO ASSY
Set"STEREO"mode with
STANDARD SURROUND key.
When speakers set ON/OFF
with SPEAKERS key, is INTER
FACE ASSY CN7006 9 pin
changed 0  5V?
Yes
DIGITAL MAIN ASSY CN603
1 pin changed 05V?
Check IC612 11, 13 pin on
DIGITAL MAIN ASSY. If it is OK,
repalce DIGITAL MAIN ASSY
No
No
Yes
Check relay signal path between
INTER FACE ASSY and DIGITAL MAIN ASSY
Analog in (e.g CD)
Select EXT. STEREO
When speakers set ON/OFF
with SPEAKERS key, is INTER
FACE ASSY CN7006 6, 7, 8,
10 pin changed 0  5V?
Analog in (e.g CD)
Select EXT. STEREO
Yes
Yes
DIGITAL MAIN ASSY CN603
2 pin, CN602 18, 19, 20 pin
changed 0 5V?
No
Check Relay ON/OFF singla a t
IC612 and IC601 on DIGITAL MAIN ASSY.
If it is OK, repalce DIGITAL MAIN ASSY
No
Check relay signal path
between INTER FACE ASSY
and DIGITAL MAIN ASSY
Only iPodUSB and HMG
can be selected for
zone 2 digital input.
BD,HDMI can't be selected.
It's specification.
Yes
Analog in output
from Zone 3 line
No
Yes
Digital inoutput
from Zone 3 line out?
No
Yes
Zone line out is OK, but speaker out NG.
Zone speaker out takes same signal path as
one of main channels.(It can be selected by
SP system setting.)
Refer to speaker (front is OK) flow.
Which channels correspond to zone, refer to
instruction manual.
Only iPodUSB and HMG
can be selected for
zone 3 digital input.
BD,HDMI can't be selected
It’s specification.
C
C
B
This is just for general reference and does not including every single case.
NO SOUND