Video System - Pioneer PDP-5020FD Service Manual

1
A

[6] VIDEO SYSTEM

Flowchart of Failure Analysis for The Video System
=> ATV
Analog tuner signal is not
displayed on the screen.
Yes
Is the input selecter set to TV?
(Analog)
B
Yes
Is a signal input to IC8001
(AVSW)? (pin 57)
Yes
Is a HS signal input to IC6811
(IFUCOM)? (pin 3)
Yes
C Which signal is not output,
main or sub signal?
MAIN
Is a signal output from IC8001?
(AVSW) (pin 45)
Yes
Has the signal arrived at IC4702?
(VDEC) (pin 22)
Yes
Are the data output from IC4702?
(VDEC) (pins 93 to 97, 99 to 104,
D
107 to 109)
Yes
Is the communication between
each IC (VDEC, ASIC) on the
MAIN Assy and the microcomputer
normal?
Yes
Replace the MAIN Assy.
E
F
60
1
2
No
Set the Input selector to TV.
(Analog)
No
Has the signal arrived at TP5337?
1
Yes
Is a signal input to TP7558?
No
Has the signal arrived at Q5306
collector?
2
SUB
No
Check around IC8001 and check the communications
between IC8001 and microcomuputer.
3
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.
4
Check around IC4702 and check the communications
No
between IC4702 and microcomuputer.
If there was no ploblem, replace the MAIN Assy.
5
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.
Waveforms
Input signal: NTSC Color-bar (Analog tuner)
IC8001 - pin 57 (in)
1
V: 500 mV/div H: 10 μsec/div
IC4702 - pins 22, 70
4
V: 500 mV/div H: 10 μsec/div
2
3
No
Replace the U5301 (TUNER).
No
Check the 40P FFC (J214) between the MAIN Assy and IO Assy.
If there was problem, replace it.
No
Has the signal arrived at C5363.
No
Is a signal output from IC4601?
(pin 49)
No
Has the signal arrived at IC4702?
(pin 70)
No
Are the data output from IC4702?
(pins 79 to 86, 88 to 90)
IC6811 - pin 3
2
V: 1 V/div H: 10 μsec/div
IC4702 (out)
5
V: 1 V/div H: 2 μsec/div
PDP-5020FD
3
4
No
Replace the U5301 (TUNER).
3
Yes
4
Yes
5
IC8001 - pins 45, 49 (out)
3
V: 500 mV/div H: 10 μsec/div
4