Philips 32PF9968/10 Service Manual page 139

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Circuit Descriptions, Abbreviation List, and IC Data Sheets
9.2 LCD Power Supply
9.2.1 42" Sets
The 42" sets in this chassis come with a serviceable Power
Supply Unit. This supply unit delivers the power for the display,
AmbiLight unit and the optional panel (bold-on) for Dynamic
Frame Insertion (DFI). Refer to chapter "Circuit Diagrams and
PWB Layouts", diagrams A1 to A3.
The power supply for the SSB and Audio part are located on
the SSB itself. For a description of the on-board power supply,
refer to Section "On-board Platform Supply".
The supply unit delivers the following voltages to the chassis:
• 12 V for bold-on panel (optional), LCD panel and AmbiLight
(optional).
• 24 V for lamp inverters.
For a block diagram see figure "Block Diagram LCD Power
Supply 42".
1P02
mains filter
mains
mains
harmonics
1308
coil
A Power-Good circuitry is built around items 7015 and 6076.
The so-called POWER-GOOD line indicates the correct
functioning of the 12 V supply. The voltage on this line is 5 V if
the voltage on the 12 V output drops below 10 volt. Refer to
figure "Power-Good circuitry".
rectifier for EUR
relay
doubler/rectifier
for USA
on
off/standby
protections :
overvoltage
overcurrent
softstart
Figure 9-4 Block diagram LCD Power Supply 42"
Q523.1U LA
1P22
resonant 12V
trafo's
5A
and bridge
24V
8A
or
198V
0.7A
frequency
controller
feedback
Figure 9-5 Power-Good circuitry
9. EN 139
for bold on 1P15
for lcd display 1P11
1M90
for ambilight 1M09
power-good = 5V if 12
V is >10 V 1P11
for lamp inverters 1314
1315
1316
1317
1319
1320
control signals 1P11
H_16770_105.eps
260307
Power_good
H_16770_106.eps
260307