Pioneer PDP-5020FD Service Manual page 51

5
[2] POWER SUPPLY UNIT
Flowchart of Failure Analysis for The POWER SUPPLY Unit
Failure analysis for the
POWER SUPPLY Unit => PS1
Failure analysis for the
POWER SUPPLY Unit => PS2
Failure analysis for the
POWER SUPPLY Unit => PS3
5
6
STB 3.4 V power is not output.
Is the cable connected firmly to
the P7 connector?
Yes
Yes
Is the cable to the P7 connector
broken?
No
Yes
Is the fuse (F102) blown?
No
Yes
Is one of the limiting resistors
(R126) blown?
No
The POWER SUPPLY Unit is
normal.
The power is not on, even though
the RELAY port is active.
Is the relay (RY102) 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-5020FD
6
7
No
Properly connect the cable between
the P7 and M2 connectors.
Replace the defective cable (J109).
Replace the POWER SUPPLY
Unit.
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.
7
8
Check the voltage at the MAIN Assy and
POWER SUPPLY Unit.
Check the resistance between D112 cathode
and JW194 (jumper),
using a tester.
• Check the relay operation at the JW281
(jumper). (Voltage: 5 V)
• Check the relay sound (click).
• Check the voltage between the JW154
(jumper) (-) and JW139 (jumper) (+).
• The voltage must be around 400 V.
(340V or less are defective.)
Caution: High voltage!
The specified voltage values are between
72 and 78 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.
8
A
B
C
D
E
F
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