Pioneer KURO PDP-LX508D, Service Manual

Page: 56 / 175

PDP-LX5080D
56
1 2 3 4
1 2 3 4
C
D
F
A
B
E
Flowchart of Failure Analysis for The Video System
No
No
Yes
Yes
Yes
Is the function correspondeing to
selected signal input selected?
Has the signal arrived at IC4601
(AVSW)?
Image for the composite or S-video
signal is not displasyed.
Select the corresponding signal
with the Input selector.
Check the flexible cable between CN8804 and CN4004.
Check the flexible cable between CN8801 and CN9351.
Check the cable between CN8802 and CN9352.
Check around input terminals.
No
Replace the FFCs or cables.
No
Specifications that does not
display in the sub-side.
=> COMP/S1
Sub
Main
Which signal is not output,
main or sub signal?
Check the emitter-follower circuit
between IC4601 and IC4801 and
repair the failure points.
No
Check around the IC that is found to
have failure in communication and
the microcomputer. If there was no
ploblem, replace the MAIN Assy.
No
Check around IC4601 and check the
communications between IC4601
and microcomuputer. If there was
no ploblem, replace the MAIN Assy.
No No
No
Replace the MAIN Assy.
Is a signal output from
IC4601? (pins 42 and 45)
Has the signal arrived at IC4801
(VDEC)?
(pins 22 and 26)
Yes
Is the communication between
each IC (VDEC, ASIC) on the
MAIN Assy and the microcomputer
normal?
Yes
Yes
Has the signal arrived at
IC4801? (pins 69 and 70)
Yes
Yes
Yes
11 10
Is a signal output from
IC4701? (pins 47 and 49)
Is the screen of main side
Analog/Digital TV?
12 13
14 15
8 9
8
IC4601 - pin 42
V: 500 mV/div H: 20
μ
S/div
9 10
IC4801 - pin 22
V: 500 mV/div H: 20
μ
S/div
11
IC4801 - pin 26
V: 500 mV/div H: 20
μ
S/div
15
IC4801 - pin 70
V: 500 mV/div H: 20
μ
S/div
12
IC4701 - pin 47
V: 500 mV/div H: 20
μ
S/div
13
IC4701 - pin 49
V: 500 mV/div H: 20
μ
S/div
14
IC4801 - pin 69
V: 500 mV/div H: 20
μ
S/div
Waveforms
Input signal: PAL Color-bar (S terminal)
IC4601 - pin 45
V: 500 mV/div H: 20
μ
S/div