Philips 32PFL3403D/85, Руководство по обслуживанию

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Circuit Descriptions, Abbreviation List, and IC Data Sheets EN 80 LC8.1U LA 9.
9.1.3 SSB Cell Layout
Figure 9-2 SSB top view
9.2 LCD Power Supply
The Power Supply Unit (PSU) in this chassis is a buy-in and is
a black-box for Service. When defective, a new panel must be
ordered and the defective panel must be returned for repair,
unless the main fuse of the unit is broken. Always replace the
fuse with one with the correct specifications! This part is
commonly available in the regular market.
Different PSUs are used in this chassis:
•
32" sets use a “Delta” PSU (DPS-182CP A)
• 42" sets use an “LG” PSU (LGIT PLHL-T721A or -T720A)
• 47" sets use an “LG” PSU (LGIT PLHL-T722A)
• 52" sets use a “Delta” PSU (DPS-411AP A).
Some Power Supply Units deliver also the high voltage to drive
the backlight of the LCD panel (then called IPB= Integrated
Power Board). These LCD panels come therefore without
inverters. In addition, all PSU’s deliver the following voltages to
the chassis:
•
High voltage to drive the backlight units (no inverters
needed)
• +3V3
STBY
to SSB
• +12 V
display
to SSB
• +12 V
audio
and -12 V
audio
to SSB
• +12 V to DC-DC converters to SSB
• +12 V to Bolt-on Supply (where applicable) to SSB
• +24 V to Bolt-on Supply (where applicable) to SSB.
9.3 DC/DC converters
On-board DC-DC converters convert the +12 V coming from
the PSU and deliver the following voltages:
•
+5 V (+5V
tuner
)
• +5 V (+5V_SW)
• +3.3 V (+3V3_SW)
• +2.5 V (+2V5)
• +1.8 V (+1V8_SW)
• +1.1 V (+1V1_SW)
• +1.2 V (+1V2)
The power supply system consists on standby, switched, and
regulated voltages. The Standby voltage, +3V3STBY, will be
available once AC supply is provided to the system. As for the
other voltages, namely switched and regulated voltages, these
are available once STANDBY signal is pulled “low” to allow
other supplies from the PSU to turn “on”. The switched supplies
are generated from the main +12V supply, while the regulated
supplies are derived from the switched supplies.
There are a number of detection circuits to detect the following
supplies; +12V, +12Vdisp and +3V3_SW. The +12V is the
main supply voltage from the PSU that enables the switched
voltages to be generated. The +12Vdisp is the supply to the
display timing controller, while the +3V3_SW is powering the
microprocessor and its flash memory.
The following diagram shows the power supply architecture of
the SSB:
H_17740_045.eps
250108
FOR FUTURE USE
FPGA
AMBI
LIGHT
CHANNEL
DECODER
HDMI
DEMULTI
PLEXER
DOUBLE
FRAME
RATE
MAIN VIDEO/
AUDIO
PROCESSING
FLASH MEMORY
DDR
HYBRID TUNER
AUDIO CLASS - D
DC - DC CONVERSION
iTV
SAW
MPEG2
DECODER/
ENCODER