Pioneer PDP-4271HD Service Manual page 83

5
Flowchart of Failure Analysis for The Drive Assy
Failure analysis for the
drive system ⇒ DR3
The abnormality is associated with
one address or one TCP?
Is the TCP control signal normal?
(See the oscilloscope photos.)
Yes
Replace the panel chassis.
In most cases of damage on one line,
the panel chassis must be replaced.
Failure analysis for the
drive system ⇒ DR4
The abnormality is associated
with a single scan line.
Is the waveform normal when the
voltage is applied to the panel?
Yes
Replace the SCAN IC.
NG
Replace the panel chassis.
Failure analysis for the
drive system ⇒ DR5
The panel mask is not displayed
properly.
Yes
Failure analysis for the
drive system ⇒ DR2
5
6
Diagnose the ADDRESS Assy.
No
Are the FFC cables properly
connected?
Yes
NG
Replace the DIGITAL Assy.
Diagnose the SCAN A and B Assys.
No
Is the cable connected properly
to the 15-pin connector?
Yes
Are the cables connected properly
between the SCAN A and B Assys?
Yes
Yes
Is the waveform of the SCAN IC
control signal from the Y DRIVE
Assy normal?
Check with the slanting ramp mask that moves.
6
7
No
Properly connect the FFC cables.
NG
If the FFC cable that connects the DIGITAL and ADDRESS Assys is in failure,
the abnormality is associated with one address in most cases.
No
Connect the cable properly.
NG
No
Reconnect the cables properly.
NG
No
Replace the Y DRIVE Assy.
PDP-4271HD
7
8
A
B
C
D
E
F
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