Sony KDL-40NX725 / KDL-46NX725 Service Manual ▷ View online
KDL-40NX725/46NX725
19
SECTION 3 - CHASSIS OVERVIEW
Switch Unit
BATL Board
TCON
G5AW Board
LD Board
HEM2 Board
HLT2 Board
Camera Module
Wireless LAN Card
FIGURE 3-2. BOARD LAYOUT FOR KDL-46NX725 ONLY
KDL-40NX725/46NX725
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SECTION 3 - CHASSIS OVERVIEW
OVERALL CIRCUIT DESCRIPTION
“Figure 3-3. Overall Block Diagram” on page 23
provides an overview
of the AZ2-F chassis. The following are descriptions of the boards
and their functions.
MAIN BOARD
Common to all models the Main Board, designated as the BATL
Board, contains the TV control, video, and audio processing circuitry.
All these functions are accomplished using the X-Reality Processor
IC9000.
TUNER
The tuner is a combination ATSC/NTSC unit. It can receive traditional
analog NTSC signals via cable or terrestrial along with ATSC digital
signals via terrestrial (8VSB) or cable (64 or 256 QAM).
X-REALITY PROCESSOR
IC9000 performs the majority of the necessary audio and video
processing on the main board.
TV Microprocessor: The CPU internal to the X-Reality processor
TV Microprocessor: The CPU internal to the X-Reality processor
controls all aspects of the television functions. Input from the user
along with monitoring of critical circuits is also performed by this
CPU.
Digital Audio and Video Decoder: The MPEG2 and Digital Dolby
Digital Audio and Video Decoder: The MPEG2 and Digital Dolby
audio streams are received from the tuner for decompression. All
video sources which are not native 1920 X 1080p 60HZ are scaled to
this resolution. Digital audio content is output to the class D amplifier
for processing and amplification.
HDMI Input and Switching: The customer can select the HDMI1,
HDMI2, HDMI3, HDMI4 input via the HDMI switch IC5500. Each
HDMI input contains a common EDI NVM (internal to IC5500) to
provide display information data to any device connected via the
HDMI inputs.
LVDS Transmitter: Integrated into IC9000 is a Low Voltage
LVDS Transmitter: Integrated into IC9000 is a Low Voltage
Differential Signaling (LVDS) transmitter. This circuit converts
the 8-bit parallel RGB video information into a set of high speed
serial lines for noise-free transmission to the TCON circuits located
internally to the LCD panel.
Scan Converter: Signal processing circuit that performs resolution
Scan Converter: Signal processing circuit that performs resolution
conversion (aspect ratio) and interlaced to progressive scan (IP)
conversion
AUDIO AMPLIFIER
The audio amplifier (IC4601) amplifies the digital audio output of the
X-Reality processor and sends it to the speakers.
TEMPERATURE SENSOR
The temperature sensor detects over-temperature conditions on the
Main Board, LCD Panel, or ambient room temperature and sends
the shutdown signal to the processor.
KDL-40NX725/46NX725
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SECTION 3 - CHASSIS OVERVIEW
POWER SUPPLY
There are different Power Supply Boards used in the models in this
manual. The type of board depends on the size of LCD panel. They
are:
G4BW (40”)
G5AW (46”)
There are 3 distinct sections on the power supply:
Standby Supply: Continuously operational as long as AC power is
G4BW (40”)
G5AW (46”)
There are 3 distinct sections on the power supply:
Standby Supply: Continuously operational as long as AC power is
applied, the standby supply generates 3.3V for the circuits requiring
power while the unit is turned off. An unregulated 19V line is present
to provide power to the main relay, PFC and main power supply at
turn-on.
Main Supply: Once the power supply receives a power-on command
Main Supply: Once the power supply receives a power-on command
from the CPU on the Main Board, the main switching supply is turned
on to provide a regulated 12V source and an regulated 24V source
for the LED power supply circuits.
Converter: Generates the B+ for the local dimming (LD board)
Converter: Generates the B+ for the local dimming (LD board)
circuits to control the backlighting level.
POWER SUPPLY FOR BACKLIGHT SYSTEM
Power for the LED backlights is provided for the LD board via the
G4BW (40”) and G5AW (46”).
LD BOARD (LOCAL DIMMING)
The LD Driver Board is controlled by the TCON/HFR Board to perform
overall backlight power-on, backlight level, and local dimming
functions. The negative voltage rail is pulse width modulated to
control the on time of the LED backlights. LED backlight brightness
is controlled in 4 separate groups (quadrants).
3D IR EMITTER
Designated as the HEM2 Board, this board is the internal 3D IR
Emitter to synchronize the 3D shutter glasses..
WIRELESS LAN BOARD
The wireless transmit/receive circuits are located on this board to
communicate with a wireless network.
SWITCH UNIT
This board contains the power, channel, and volume up/down and
menu buttons.
USB CAMERA
A USB camera is located on the front bezel below the Sony logo.
Special software is located inside IC9000 to use the camera for
power and picture control management. Face recognition software
can determine whether someone is viewing the television. The
number of people, distance from the TV, location from center, and
whether the person(s) are looking at the television provides data to
control the picture brightness and contrast. A lack of face recognition
(no one viewing the television) can also be used to turn off the
backlights, and, eventually turn the TV off for power savings.
KDL-40NX725/46NX725
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SECTION 3 - CHASSIS OVERVIEW
IR BOARD
Designated as the HLT2 Board, the IR Board contains the power,
standby, and timer LED’s are located on this board along with the IR
remote receiver and light level sensor.
LCD PANEL ASSEMBLY
The LCD Panel Assembly includes the LCD Panel, TCON Board,
and LED Backlight system.
NOTE: The LD Board is not always included with the LCD Panel.
NOTE: The LD Board is not always included with the LCD Panel.
Check with the LCD panel manual for the most update information
regarding this.
The LCD Panel contains the actual liquid crystals, color filters, and
The LCD Panel contains the actual liquid crystals, color filters, and
polarizers. The liquid crystals are manipulated by the applied voltage
to pass a specific amount of light - from the backlight- depending on
the level of voltage applied.
The TCON performs all the control, timing, charge, and discharge
The TCON performs all the control, timing, charge, and discharge
functions driving the operation of the LCD Panel.
A new LCD Panel assembly from parts will include the following
A new LCD Panel assembly from parts will include the following
items.
1. LCD Panel
2. LED Backlighting Components (varies)
3. TCON Board
TCON BOARD
The TCON Board communicates between the LCD Panel and the
microprocessor on the Main Board. (NOTE: The TCON Board is not
available as a replacement part for all models.)
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