PDP-4271HD
89
5
6
7
8
5
6
7
8
C
D
F
A
B
E
Is the function corresponding to
selected signal input selected?
Select the corresponding signal
with the input selector.
No
Replace flexible cable.
No
Check the communication between
the CN8802 and CN4004 or
between CN8803 and CN4005 or
around of jack.
No
Check the circuit between IC4901 and
IC5301 and replace broken parts.
No
The panel is defective.
No
Check the circuit between IC4901 and
IC5101 and replace broken parts.
No
Check around IC4901 and check the
communications between IC4901
and the microcomputer. If there was
no ploblem replace MAIN Assy.
No
Check around the IC that is found to
have a failure in communication and
the microcomputer. If there was no
ploblem replace MAIN Assy.
No
No
Replace the MAIN Assy.
Yes
Yes
Image for the component signals
is not displayed.
⇒
COMP/PC1
Has the signal arrived at IC4901 ?
Yes
What is a input signal ?
Is a signal output from IC4901?
(pin 41, 43, 45)
Has the signal arrived at IC5301?
(pin 43, 48, 54)
Yes
Has the symptom been settled
when the MAIN Assy is replaced?
Yes
Yes
Is the communication between
each IC on the MAIN Assy and
the microcomputer nomal?
Yes
Has the signal arrived at IC5101 ?
(pin 154, 162, 170)
Yes
Yes
Input sigal: 480i
Input sigal: except 480i
15
18
Is a signal output from IC4901?
(pin 30, 32, 34)
14
13
17
16
13
IC4901 - pin 41 (component_PR)
V: 500 mV/div H: 10
µ
sec/div
13
IC4901 - pin 41 (PC_R)
V: 500 mV/div H: 10
µ
sec/div
15
IC4901 - pin 45 (component_Y)
V: 500 mV/div H: 10
µ
sec/div
15
IC4901 - pin 45 (PC_G)
V: 500 mV/div H: 10
µ
sec/div
17
IC5301 - pin 48 (component)
V: 500 mV/div H: 10
µ
sec/div
17
IC5301 - pin 48 (PC)
V: 500 mV/div H: 20
µ
sec/div
Waveforms
Input signal: Color-bar
14
IC4901 - pin 43 (component_PB)
V: 500 mV/div H: 10
µ
sec/div
14
IC4901 - pin 43 (PC_B)
V: 500 mV/div H: 10
µ
sec/div
16
IC4901 - pin 43 (component)
V: 500 mV/div H: 10
µ
sec/div
16
IC4901 - pin 43 (PC)
V: 500 mV/div H: 10
µ
sec/div
18
IC5301 - pin 54 (component)
V: 500 mV/div H: 20
µ
sec/div
18
IC5301 - pin 54 (PC)
V: 500 mV/div H: 20
µ
sec/div
No video from component
Flowchart of Failure Analysis for The Video System