Diagnosis - Pioneer PDP-4270XA Service Manual

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5. DIAGNOSIS

5.1 TROUBLE SHOOTING
5.1.1 FLOWCHART OF FAILURE ANALYSIS FOR THE WHOLE UNIT
A
Flowchart of Failure Analysis for The Whole Unit
START
Problems concerning STB status
Is the STB LED lit?
Yes
B
Problems concerning the power
C
Can the unit be turned on
(Relay ON)?
Yes
A shutdown occurs.
No
D
A power-down occurs.
No
Problems concerning lighting of the panel
Does the screen display reset
lighting?
Yes
E
Is the panel arbitrary turned on or
off repeatedly? Or do luminescent
spots appear on the screen?
No
Is there any local abnormality
on the screen?
Yes
F
A
74
1
2
No
Is STB 3.3 V power supplied?
(Check the power at the IF micro-
computer on the MAIN Assy.)
Yes
Is the voltage at AC_DET on the
POWER SUPPLY Unit high?
Yes
Failure analysis for the
MAIN Assy. ⇒ MA1
No
Is the power shutdown?
Yes
Yes
See "Shutdown diagnosis." ⇒ SD
Yes
See "Power-down diagnosis." ⇒ PD
No
Is the drive off?
No
Failure analysis for the
drive system ⇒ DR1
Yes
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS3
Failure analysis for the
drive system ⇒ DR2
Yes
No
Is the abnormality associated
with one address or one TCP?
Yes
Failure analysis for the
drive system ⇒ DR3
PDP-427XD
2
3
No
Check if the cable that connects
the POWER SUPPLY and MAIN
Assys is firmly connected.
The blue LED on the DIGITAL Assy indicates ON/STB
of the panel and causes for a power-down or shutdown.
If neither the blue nor red LED lights, it is likely that the
power to the STB system is not supplied. (failure, PASV-STB status)
No
Replace the POWER SUPPLY
Unit.
Is the voltage at the RELAY port
No
of the connectors between the
DIGITAL and POWER SUPPLY
Assys H (3.3 V)?
Yes
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS2
A power-down will not be generated if the drive is off.
Yes
Turn the drive on.
In a case where luminescent spots appear
or the panel is repeatedly turned on or off
In a case where luminescent spots appear
No
Is the abnormality associated
with a single scan line?
Yes
Failure analysis for the
drive system ⇒ DR4
3
4
NG
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS1
No
Failure analysis for the
MAIN Assy. ⇒ MA2
If the module microcomputer does not
receive the PON command, it is likely
that the main microcomputer did not
issue the command.
• Check the DRF SW.
• Before turning the drive off with the RS-232C
commands or using the remote control unit,
turn the unit off.
No
Replace the panel chassis.
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