Pioneer KURO PDP-LX508D, Service Manual

Page: 57 / 175

PDP-LX5080D
57
5 6 7 8
5 6
7
8
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?
Image for the RGB input signal
is not displasyed.
Select the corresponding signal
with the Input selector.
Is the screen of main side
Analog/Digital TV?
No
Has the signal arrived at IC4601
(AVSW)?
No
Specifications that does not
display in the sub-side.
=> RGB
Sub
Main
Which signal is not output,
main or sub signal?
Check the circuit between IC4701 and
IC4801 and replace broken parts.
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
No
Check around IC4701 and check the
communications between IC4701
and microcomuputer. 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
Replace the MAIN Assy.
Is a signal output from IC4701?
(pins 41, 43 and 45)
Has the signal arrived at IC4801?
(pins 27, 28 and 65)
Yes
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)
Has the signal arrived at IC4701
(RGBSW)?
Yes
Yes
Yes
21 20 19
Is a signal output from IC4601?
(pins 47 and 49)
12 13
14 15
17 16 18
16
IC4701 - pin 41
V: 500 mV/div H: 20
μ
S/div
17 18
IC4701 - pin 45
V: 500 mV/div H: 20
μ
S/div
19
IC4801 - pin 27
V: 500 mV/div H: 20
μ
S/div
20
IC4801 - pin 28
V: 500 mV/div H: 20
μ
S/div
21
IC4801 - pin 65
V: 500 mV/div H: 20
μ
S/div
Waveforms
Input signal: PAL Color-bar (SCART RGB terminal)
IC4701 - pin 43
V: 500 mV/div H: 20
μ
S/div
Check the flexible cables between the CN8804 and
CN4004 or around of input terminals. No
Replace the FFCs or cables.
Check the emitter-follower circuit
between IC4601 and IC4801 and
repair the failure points.