Pioneer PDP-5020FD Service Manual page 61

5
=> COMP/S1
Image for the composite or S-video
signal is not displayed.
Yes
Is the function correspondeing to
selected signal input selected?
Yes
Has the signal arrived at IC8001?
(AVSW)
6 7
Yes
Which signal is not output,
main or sub signal?
MAIN
Is a signal output from IC8001?
(AVSW) (pins 42, 45)
8 9
Yes
Has the signal arrived at IC4702?
(VDEC) (pins 22, 26)
10 11
Yes
Is the communication between
each IC (VDEC, ASIC) on the
MAIN Assy and the microcomputer
normal?
Yes
Replace the MAIN Assy.
Waveforms
Input signal: NTSC Color-bar (S termial)
IC8001 - pin 68 (Y)
6 7
V: 500 mV/div H: 20 μsec/div
IC4702 - pin 26 (Main C)
11 12
V: 500 mV/div H: 20 μsec/div
5
6
No
Select the corresponding signal
with the Input selector.
No
Check around the input terminals.
SUB
No
Check around IC8001 and check the communications
between IC8001 and microcomuputer.
If there was no ploblem, replace the IO Assy.
No
Check the 40P FFC (J214) between MAIN Assy and
IO Assy. If there was problem, replace it.
Check around the IC that is found to have failure in
No
communication and the microcomputer.
If there was no ploblem, replace the MAIN Assy.
IC8001 - pin 70 (C) IC8001 - pin 45 (Main Y)
8
V: 500 mV/div H: 20 μsec/div V: 500 mV/div H: 20 μsec/div
IC8001 - pin 49 (Sub Y) IC8001 - pin 47 (Sub C)
13
V: 500 mV/div H: 20 μsec/div V: 500 mV/div H: 20 μsec/div
6
7
NG
Replace the IO Assy.
Is the screen of main side Tuner?
No
Is a signal output from IC8001?
(pins 47, 49)
No
Has the signal arrived at IC4702?
(pins 69, 70)
IC8001 - pin 42 (Main C)
9
V: 500 mV/div H: 20 μsec/div
IC4702 - pin 70 (Sub Y)
14
V: 500 mV/div H: 20 μsec/div
PDP-5020FD
7
8
No
Yes
Specifications that does not
display in the sub-side.
12 13
Yes
14 15
Yes
IC4702 - pin 22 (Main Y)
10
V: 500 mV/div H: 20 μsec/div
IC4702 - pin 69 (Sub C)
15
V: 500 mV/div H: 20 μsec/div
8
A
B
C
D
E
F
61