Flowchart Of Failure Analysis For The Digital Assy - Pioneer PDP-4270XA Service Manual

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5.1.3 FLOWCHART OF FAILURE ANALYSIS FOR THE DIGITAL ASSY

Flowchart of Failure Analysis for The DIGITAL Assy
Failure analysis for the
DIGITAL Assy ⇒ DG1
The on-screen display (OSD) is
not properly indicated.
Is V sync/H existence judgment
detected by issuing the QSI
command?
Yes
Is the indication position correct?
Yes
Is the tone correct?
Yes
Replace the MAIN Assy.
5
6
• If the OSD is not properly displayed although the panel mask is properly displayed,
a failure exists in the path from the output of IC8201 on the MAIN Assy to IC3401 on the DIGITAL Assy.
→ If only the OSD is abnormal, the MAIN Assy is in failure.
No
Is the sync signal properly output
from the MAIN Assy?
Yes
No
Is the 50-pin FFC cable firmly
connected?
Yes
Is the 50-pin FFC cable broken?
No
Is the FFC connector poorly
contacted?
Yes
DIGITAL : D11
MAIN : M1
Replace the MAIN Assy.
No
It is most likely that the sync signal is abnormal.
No
It is most likely that the video signal data are missing.
6
7
No
Replace the MAIN Assy.
If neither the V frequency nor H existence judgment is inappropriate, it is most likely
that the output from the DIGITAL Assy is in free run and that the screen only displays
reset lighting.
(It is judged that the drive, POWER SUPPLY Unit and the panel are normal.)
No
Firmly connect the 50-pin FFC
cable.
When disconnecting the FFC cable, take care not to damage the CN3001 connector
on the DIGITAL Assy, which can easily be damaged.
Yes
Replace the 50-pin FFC cable.
In a case of D11
No
Replace the DIGITAL Assy.
In a case of M1
Replace the MAIN Assy.
PDP-427XD
7
8
A
B
C
D
E
F
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