Pioneer PDP-4270XA Service Manual page 92

1
A
Flowchart of Failure Analysis for The Audio System
A
Has the sound of the Analog
broadcasting output?
Yes
B
Has the sound of the HDMI
output?
Yes
Has the sound of the Digital
broadcasting output?
Yes
C
Has the sound of the SCART input
or PC input output?
D
Yes
Has the sound of the side input
output?
E
F
92
1
2
Is a signal input to IC4701?
No
(pins 22, 23)
50 51
Yes
Check the communications around the
IC4701 and between the IC4701 and
the microcomputer. If there was no
ploblem, replace the MAIN Assy.
Is a signal output from IC5402?
No
(pins 7, 8)
52 53
Yes
Check the communications around the
IC4701 and between the IC4701 and
the microcomputer. If there was no
ploblem replace the MAIN Assy.
Check the FFC and cables between
No
the MAIN Assy and R07 DT Assy.
Does not sound output even if replace
them?
Yes
Is a signal input to IC4701?
(pins 19, 20)
50 51
Yes
Check the communications around the
IC4701 and between the IC4701 and
the microcomputer. If there was no
ploblem replace the MAIN Assy.
Check the FFC between CN8802
No
and CN4004 or between CN9003
and CN4005, or check around the
input terminals.
Yes
Is a signal input to IC4701?
50 51
Yes
Check the communications around the
IC4701 and between the IC4701 and
the microcomputer. If there was no
ploblem replace the MAIN Assy.
Check the cables between CN9002
No
and CN9205 or between CN9001
and CN9202, or check around the
pin jack.
Yes
Check the FFC between CN8802
and CN4004 or between CN9003
and CN4005.
Yes
Is a signal input to IC4701?
50 51
Yes
Check the communications around the
IC4701 and between the IC4701 and
the microcomputer. If there was no
ploblem replace the MAIN Assy.
PDP-427XD
2
3
Check the communications around
No
the U4501 (FE) and between the
U4501 and IC4701.
No
Is a signal output from IC5401?
OK
Replace the IC5402.
Poor contact of the connector or
No
FFC, or cable is defective.
Replace FFC or cable.
No
Is a signal input to IC4000 of the
R07 DT Assy?
Yes
Check around IC4000 and repair
the failure points.
NG
Replace the FFC.
Check between input terminal and
No
CN4004 and CN4005 and repair
the failure points.
NG
Replace the cables.
NG
Replace the FFC.
Check between side input terminal
No
and CN4004 and CN4005 and
repair the failure points.
3
4
NG Replace the U4501 (FE) and
repair the failure points.
NG
Replace the IC5401.
No
Replace the R07 DT Assy.
Waveforms
Input signal: L/R 1 kHz
IC4701 - pin 22
50
V: 1 V/div H: 400 µS/div
IC4701 - pin 23
51
V: 1 V/div H: 400 µS/div
IC5402 - pin 7
52
V: 1 V/div H: 400 µS/div
IC5402 - pin 8
53
V: 1 V/div H: 400 µS/div
4