Pioneer PDP-5071PU Service Manual page 92

1
Flowchart of Failure Analysis for The Video System
A
No video from Composite or S-VIDEO
⇒ COMP/S1
Image for the composite or s-video
signal is not displayed.
Yes
Is the function correspondeing to
selected signal input selected?
Yes
Is the compornent cable is
B
connect to jack? (Input2, Input4)
Yes
Has the signal arrived at IC4701?
(pin 85, 91, 60)
Yes
Which signal is not output,
main or sub signal?
MAIN
Is a signal output from IC4701?
(pin 47, 49)
3
Yes
C
Has the signal arrived at IC5101?
(pin 148, 158)
7
Yes
Is the communication between
each IC on the MAIN Assy and the
microcomputer normal?
Yes
Has the symptom been settled
when the MAIN Assy is replaced?
Yes
D
Replace the MAIN Assy.
Waveforms
Input signal: Color-bar
IC4701 - pin 85, 91, 60
1
V: 500 mV/div H: 20 µsec/div
E
IC4701 - pin 45 (composite)
5
V: 500 mV/div H: 20 µsec/div
F
92
1
2
No
Select the corresponding signal
with the Input selector.
No
Disconnect component and
confirm again.
No
Check the flexible cable between
CN8802 and CN4004.
1
Check the flexible cable between
CN8803 and CN4005.
SUB
No
Check around IC4701 and check the
communications between IC4701
4
and microcomuputer. If there was
no ploblem replace the MAIN ASSY.
No
Check the circuit between IC4701 and
IC5101 and replace broken parts.
8
No
Check around the IC that is found to
have failure in communication and
the microcomputer. If there was no
ploblem replace MAIN Assy
No
The panel is defective.
IC4701 - pin 57 IC4701 - pin 47 (s-video)
2 3
V: 500 mV/div H: 20 µsec/div V: 500 mV/div H: 20 µsec/div
IC7001 - pin 3 (composite) IC5101 - pin 148 (composite)
6 7
V: 500 mV/div H: 20 µsec/div V: 500 mV/div H: 20 µsec/div
PDP-5071PU
2
3
NG
Replace the TANSHI Assy.
NG
Replace or reconnect flexible cable.
No
Is a signal output from IC4701?
Yes
Has the signal arrived at IC7001?
(pin 3)
IC4701 - pin 49 (composite)
4
V: 500 mV/div H: 20 µsec/div
IC5101 - pin 148 (s-video)
7
V: 500 mV/div H: 20 µsec/div
3
4
5
No
Check the circuit between IC4701 and
IC7001 and replace broken parts.
6
IC4701 - pin 49 (s-video)
4
V: 500 mV/div H: 20 µsec/div
IC5101 - pin 158 (s-video)
8
V: 500 mV/div H: 20 µsec/div
4