Pioneer PDP-4270XA Service Manual page 76

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5.1.2 FLOWCHART OF FAILURE ANALYSIS FOR THE POWER SUPPLY UNIT
A
Flowchart of Failure Analysis for The POWER SUPPLY Unit
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS1
B
C
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS2
D
Failure analysis for the
POWER SUPPLY Unit. ⇒ PS3
E
F
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2
STB 3.3 V power is not output.
Is the cable connected firmly to
the P8 connector?
Yes
Yes
Is the cable to the P8 connector
broken?
No
Is the fuse (F101) blown?
Yes
Is one of the limiting resistors
(R104/R105) blown?
Yes
The POWER SUPPLY Unit is
normal.
The power is not on, even though
the RELAY port is active.
Is the relay (RL102) on?
Yes
Is the PFC voltage normal?
Yes
The POWER SUPPLY Unit is
normal.
The cells of the panel do not
light normally.
Is the VADR voltage within the
specified values?
Yes
Yes
Is there a fluctuation in the
VADR voltage?
No
Is the VSUS voltage within the
specified range?
Yes
Yes
Is there a fluctuation in the
VSUS voltage?
No
The POWER SUPPLY Unit is
normal.
PDP-427XD
2
3
No
Properly connect the cable
between the P8 and M1 connectors.
Replace the defective cable (J105).
No
Replace the POWER SUPPLY
Unit.
No
Replace the POWER SUPPLY
Unit.
No
Replace the POWER SUPPLY
Unit.
No
Replace the POWER SUPPLY
Unit.
No
Replace the POWER SUPPLY
Unit.
Replace the POWER SUPPLY
Unit.
No
Replace the POWER SUPPLY
Unit.
Replace the POWER SUPPLY
Unit.
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4
Check the voltage at the DIGITAL Assy and
POWER SUPPLY Unit.
Check the resistance between L102 (lead
nearest R104) and the D121 anode,
using a tester.
• Check the relay operation at the terminal
(Pin 11 of P4). (Voltage: 3.3 V)
• Check the relay sound (click).
• Check the voltage between the D204
cathode and RC101 (negative) terminal.
• The voltage must be around 390 V
(failure if it is 340 V or less).
Caution: High voltage!
The specified voltage values are between
57 and 63 V.
The ripple must be within 5 V.
The specified voltage values are between
200 and 210 V (VSU: 125/35°C).
The ripple must be within 10 V.
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