Sony Bravia KDL-40BX450 User manual

SERVICE / TRAINING MANUAL
LCD Digital Color TV
AZ3FK Chassis
Segment: P-2F
9-883-873-01
Self Diagnosis
Supported model
Version Date Subject
1.0 2/24/2012 Original Manual Release Date
ORIGINAL MANUAL ISSUE DATE: 2/2012
HISTORY INFORMATION FOR THE FOLLOWING MANUAL:

SERVICE / TRAINING MANUAL
LCD Digital Color TV
AZ3FK Chassis
Segment: P-2F
9-883-873-01
Self Diagnosis
Supported model
KDL-40BX450

MODEL LIST
MODEL COMMANDER DESTINATION MODEL COMMANDER DESTINATION
9-883-873-01
KDL-40BX450 RM-YD080 US/CND
KDL-40BX450 RM-YD080 LA/MX
KDL-40BX451 RM-YD080 CND
KDL-40BX451 RM-YD080 MX
KDL-46BX450 RM-YD080 US/CND
KDL-46BX450 RM-YD080 LA/MX
KDL-46BX451 RM-YD080 MX

KDL-40BX450/40BX451/46BX450/46BX451 i
TABLE OF CONTENTS
Cautions and Warnings...................................................................................ii
Section 1 - Features and Overview ................................................................1
Features ........................................................................................................1
Specications ................................................................................................1
Chassis Overview..........................................................................................3
Overall Circuit Description.............................................................................4
Main Board ...............................................................................................4
Power Supply Board .................................................................................4
IR Board....................................................................................................4
Switch Unit................................................................................................4
LCD Panel Assembly................................................................................5
Section 2 - Troubleshooting ...........................................................................6
Overview .......................................................................................................6
Updating the Software ..............................................................................6
Self Diagnosis Function.................................................................................6
Standby LED Blink Count .........................................................................6
Viewing the Self Check Diagnosis History................................................7
Triage Chart...................................................................................................8
Section 3 - Flow Charts and Diagrams ..........................................................9
Block Diagram ...............................................................................................9
No Power ................................................................................................10
Standby LED Blinking .............................................................................12
No Video .................................................................................................13
Section 4 - Disassembly/Part Number Information ....................................15
Table-Top Stand and Rear Cover Removal.................................................15
Handling the LVDS FFC Connector.............................................................16
Disconnecting the LVDS FFC Connector ...............................................16
Connecting the LVDS FFC Connector....................................................16
Main Board (A) and Power Supply Board (G10/G11) Removal...................17
Panel Brackets and LCD Panel Removal....................................................18
Cleaning the LCD Panel .........................................................................18
Connectors ..................................................................................................19
Screws ........................................................................................................19
Accessories and Packaging ........................................................................20
Miscellaneous..............................................................................................20
Wire Dressing..............................................................................................21
Section 5 - Updates and Adjustments .........................................................22
Overview .....................................................................................................22
Software Updates for Customers ................................................................22
Software Updates for Servicers...................................................................22
Software Update Responsibility..............................................................23
Checking the Software Version...............................................................23
Examples of Software Correctable Symptoms .......................................23
Overview .....................................................................................................24
Updating the Software.................................................................................24
Accessing Service Adjustment Mode ..........................................................24
Selecting the Panel ID Code .......................................................................25
Accessing Factory Adjustment Mode ..........................................................26
Adjusting the Color Temperature ............................................................26
APPENDIX A: ENCRYPTION KEY COMPONENTS .................................... A-1

KDL-40BX450/40BX451/46BX450/46BX451 ii
CAUTION
These servicing instructions are for use by qualied service personnel only.
To reduce the risk of electric shock, do not perform any servicing other than
that contained in the operating instructions unless you are qualied to do so.
WARNING!!
An isolation transformer should be used during any service to avoid possible
shock hazard, in case of live chassis.
!
SAFETY-RELATED COMPONENT WARNING!!
There are critical components used in LCD color TVs that are important for
safety. These components are identied with shading and
!
mark on the
schematic diagrams and the parts list. It is essential that these critical parts
be replaced only with the part number specied in the parts list to prevent
electric shock, re, or other hazard.
NOTE: Do not modify the original design without obtaining written permission
from the manufacturer or you will void the original parts and labor warranty.
CAUTIONS AND WARNINGS
ATTENTION!!
Ces instructions de service sont à l’usage du personnel de service qualié
seulement. Pour prévenir le risque de choc électrique, ne pas faire l’entretien
autre que celui contenu dans le Mode d’emploi à moins que vous soyez
qualié faire ainsi.
ALERTE!!
An d’eviter tout risque d’electrocution provenant d’un chássis sous tension,
un transformateur d’isolement doit etre utilisé lors de tout dépannage.
!
ATTENTION AUX COMPOSANTS
RELATIFS A LA SECURITE!!
Les composants identies par une trame et par une marque
!
sur les
schemas de principe, les vues explosees et les listes de pieces sont d’une
importance critique pour la securite du fonctionnement. Ne les remplacer
que par des composants Sony dont le numero de piece est indique dans le
present manuel ou dans des supplements publies par Sony. Les reglages
de circuit dont l’importance est critique pour la securite du fonctionnement
sont identies dans le present manuel. Suivre ces procedures lors de
chaque remplacement de composants critiques, ou lorsqu’un mauvais
fonctionnement suspecte.

KDL-40BX450/40BX451/46BX450/46BX451 iii
CAUTIONS AND WARNINGS
SETTING UP AND CARRYING THE TV
●Disconnect all cables when carrying the TV.
●Carry the TV with the adequate number of people; larger size TVs require two or more people.
●Correct hand placement while carrying the TV is very important for safety and to avoid damage.
USE CAUTION WHEN HANDLING THE LCD PANEL
When repairing the LCD panel, be sure you are grounded by using a wrist band.
When installing the LCD panel on a wall, the LCD panel must be secured using the 4 mounting holes on the rear cover.
1. Do not press on the panel or frame edge to avoid the risk of electric shock.
2. Do not scratch or press on the panel with any sharp objects.
3. Do not leave the module in high temperatures or in areas of high humidity for an extended period of time.
4. Do not expose the LCD panel to direct sunlight.
5. Avoid contact with water. It may cause a short circuit within the module.
6. Disconnect the AC power when replacing the backlight or inverter circuit.
(High voltage occurs at the inverter circuit at 650Vrms.)
7. Always clean the LCD panel with a soft cloth material.
8. Use care when handling the wires or connectors of the inverter
circuit. Damaging the wires may cause a short.
9. Protect the panel from ESD to avoid damaging the electronic
circuit (C-MOS).
10. During the repair, DO NOT leave the Power On for more than
1 hour while the TV is face down on a cloth.

KDL-40BX450/40BX451/46BX450/46BX451 iv
CAUTIONS AND WARNINGS
CLEANING THE LCD PANEL
CAUTION: When cleaning the TV, be sure to unplug the power cord to avoid any chance of electric shock.
Clean the cabinet of the TV with a dry soft cloth.
Wipe the LCD screen gently with a soft cloth.
;Stubborn stains may be removed with a cloth slightly moistened with a solution of mild soap and warm water.
;If using a chemically pretreated cloth, please follow the instruction provided on the package.
;Never use strong solvents such as a thinner, alcohol or benzine for cleaning.
;Periodic vacuuming of the ventilation openings is recommended to ensure proper ventilation.
;Do Not use paper towels, any type of abrasive pad, rags, rubber or vinyl materials to clean the screen. Using these materials could easily scratch the
screen which may result in permanent damage.
;Do Not use any cleaning product containing alkaline/acid cleaner, scouring powder, or volatile solvent, such as alcohol, ammonia, benzine, thinner or
insecticide. Using any of these harsh cleaners may result in permanent damage to the screen.
;Do Not spray water or detergent directly onto the TV screen . If liquid drips into the bottom of the screen it may cause a failure.

KDL-40BX450/40BX451/46BX450/46BX451 v
CAUTIONS AND WARNINGS
SAFETY CHECK-OUT
After correcting the original service problem, perform the following safety
checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered
connections. Check the entire board surface for solder splashes
and bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that
you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described in “Leakage Test”.
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and from all
exposed metal parts to any exposed metal part having a return to chassis,
must not exceed 0.5 mA (500 microamperes). Leakage current can be
measured by any one of three methods.
1. A commercial leakage tester.
Follow the manufacturers’ instructions provided with the tester.
2. A battery-operated AC milliammeter.
3. Measuring the voltage drop across a resistor by means of a VOM
or battery-operated AC voltmeter. The “limit” indication is 0.75 V, so
analog meters must have an accurate low voltage scale. Nearly all
battery-operated digital multimeters that have a 2 VAC range are
suitable. (see Figure A)
To Exposed Metal
Parts on Set
0.15 µF
Earth Ground
AC
Voltmete
r
(0.75V)
Figure A. Use an AC voltmeter to check AC leakage.
HOW TO FIND A GOOD EARTH GROUND
The cover-plate retaining screw on most AC outlet boxes is at earth ground.
Verify the AC outlet box retaining screw ground by connecting a 60W to
100W incandescent (not a neon or uorescent lamp) between the hot side of
the receptacle and the retaining screw. Try both slots, if necessary, to locate
the hot side on the line; the lamp should light at normal brilliance if the screw
is at ground potential. (see Figure B)
Figure B. Checking for earth ground.
Trouble Light
AC Outlet Box

KDL-40BX450/40BX451/46BX450/46BX451 1
FEATURES
The AZ3FK chassis is one of several designs for the 2012 model line of
Sony Bravia® LCD televisions. This manual covers the following models:
KDL-40BX450
KDL-40BX451
KDL-46BX450
KDL-46BX451
The BRAVIA® Sync™ BX45x series LED LCD HDTV
●Brilliant Full HD (1080p) picture quality
●Four HD inputs for a cable box, PS3™ and more1
●Share your pictures on the big screen via USB input
●Crisp detail & contrast w/ Clear Resolution Enhancer
●Optimized picture based on what you’re watching
●Less grain & a clear picture w/ Digital Noise Reduction
●Theater-like movie viewing with 24p True Cinema
●One remote for multiple devices with BRAVIA® Sync™2
SECTION 1 - FEATURES AND OVERVIEW
SPECIFICATIONS
System
Television system
ATSC (8VSB terrestrial): ATSC compliant 8VSB
QAM on cable: ANSI/SCTE 07 2000 (Does not include CableCARD functionality)
Channel coverage
Analog Cable: 1 - 135 / Digital Cable: 1 - 135
Panel system
Speaker output
KDL-46/40BX451: 8 W + 8 W
Input/Output jacks
CABLE/ANTENNA
VIDEO IN 1
AUDIO: 500 mVrms (Typical) / Impedance: 47 kilohms
COMPONENT IN YPBPR(Component Video): Y: 1.0 Vp-p, 75 ohms unbalanced,
sync negative / PB:0.7 Vp-p, 75 ohms
PR: 0.7 Vp-p, 75 ohms / Signal format: 480i, 480p, 720p, 1080i, 1080p
AUDIO: 500 mVrms (Typical) / Impedance: 47 kilohms
HDMI IN 1/2
Audio: Two channel linear PCM 32, 44.1
and 48 kHz, 16, 20 and 24bits, Dolby Digital
PC Input (see Operating Instructions)
AUDIO OUT
DIGITAL AUDIO OUT
(OPTICAL)
PCM/Dolby Digital optical signal
evitisop,smho57,p-pV7.0,BGRgolana,nip-51bus-DNICP
See the PC Input Signal Reference Chart for PC and HDMI IN on page 50.
PC/HDMI IN 1 AUDIO IN
oediVdnacisuM,otohP:054XB04/64-LDKBSU
KDL-46/40BX451: Photo and Video
NTSC: American TV standard
Analog terrestrial: 2 - 69 / Digital terrestrial: 2 - 69
LCD (Liquid Crystal Display) Panel
KDL-46/40BX450: 6 W + 6 W
75-ohm external terminal for RF inputs
VIDEO: 1 Vp-p, 75 ohms unbalanced, sync negative
HDMI: Video: 480i, 480p, 720p, 1080i, 1080p, 1080/24p
500 mVrms (typical)
Stereo mini jack, 500 mVrms, (Typical) / Impedance: 47 kilohms
1. Cables sold separately.
2. Syncs with BRAVIA® Sync or Theatre Sync™ products.

KDL-40BX450/40BX451/46BX450/46BX451 2
SECTION 1 - FEATURES AND OVERVIEW
•Optional accessories availability depends on its stock.
•Design and specications are subject to change without notice.
*Dimensions and mass are approximate values.
Mass* with stand (kg)
(lb.)
17.2
37.9
13.8
30.4
without stand (kg)
(lb.)
16.0
35.3
12.8
28.2
Supplied accessories
Guide (1)/Warranty Card (1)/Safety and Regulatory Booklet (1)/Software License (1)/Stand
installation guide (1)/Table-Top Stand (1 set)/Screw (3)
common to all models
Optional accessories
Remote control RM-YD080 (1)/Size AA batteries (2)/Operating Instructions (1)/Quick Setup
Connecting cables / Support Belt Kit / Wall-Mount Bracket: SU-WL500
Model name KDL-46BX450
KDL-46BX451
KDL-40BX450
KDL-40BX451
Power and others
Power requirement
Power consumption W 851W 881
in use
in standby
Screen size*
(inches measured diagonally) 0464
)lacitrev( senil 080,1 × )latnoziroh( stod 029,1 noituloser yalpsiD
Speaker/Full range (2) (mm)
(inches)
40 × 100
(1 5/8 × 4)
Dimensions* with stand (mm)
(inches)
1,112 × 713 × 279
43 7/8 × 28 1/8 × 11
980 × 639 × 231
38 5/8 × 25 1/4 × 9 1/8
without stand (mm)
(inches)
1,112 × 675 × 97
43 7/8 × 26 5/8 × 3 7/8
980 × 601 × 94
38 5/8 × 23 3/4 × 3 3/4
wall-mount hole pattern
(mm)300 × 300
wall-mount screw size
(mm)M6 (length: 8-12mm)
Less than 0.2 W with 120 V AC and with 240 V AC less than 0.3 W
110-240 V AC, 50/60 Hz (U.S.A./Canada/Mexico 120 V AC, 60 Hz)

KDL-40BX450/40BX451/46BX450/46BX451 3
SECTION 1 - FEATURES AND OVERVIEW
CHASSIS OVERVIEW
The primary circuits in the AZ3FK chassis consist of a Main Board (A Board), Power Supply Board (G10 Board for the 40” models, and G11 Board for the 46”
models), the IR Board (H Board), the Switch Unit, and the LCD Panel Assembly which includes the TCON Board and the Inverter MT Board.
NOTE: For connector part number information, refer to “Connectors” on page 19. For Wire Dressing information, refer to “Wire Dressing” on page 21.
SWITCH
UNIT
G10/G11
INV
A
H
BOARD LAYOUT

KDL-40BX450/40BX451/46BX450/46BX451 4
SECTION 1 - FEATURES AND OVERVIEW
CPU: The CPU internal to the MT5389 processor controls all aspects of
the television functions. Input from the user along with monitoring of critical
circuits is also performed by this CPU.
LVDS Transmitter: Integrated into the MT5389 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.
POWER SUPPLY BOARD
There are 2 different Power Supply boards used in the models in this
manual. The type of board depends on the size of LCD panel. They are:
●G10 for the 40” models
●G11 for the 46’ models
There are 2 distinct sections on the power supply:
Standby Supply: Continuously operational as long as AC power is applied,
the standby supply generates 3.3VDC for the circuits requiring power while
the unit is turned off. An unregulated 15-volt 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 from
the CPU on the A board, the main switching supply is turned on to provide
a regulated 12V source, a dedicated un-regulated 15V for the audio circuits
and an unregulated 24V source for the inverter circuit.
IR BOARD
Designated as the H Board, the IR Board contains the power, standby, and
timer LED’s that is located on this board along with the IR remote receiver
and light level sensor.
SWITCH UNIT
This board contains the power, channel and volume up/down, and menu
buttons.
OVERALL CIRCUIT DESCRIPTION
“Block Diagram” on page 9 provides an overview of the AZ3FK chassis.
The following are descriptions of the boards and their functions.
MAIN BOARD
Common to all models utilizing the AZ3FK chassis, the Main Board contains
most of the video processing circuitry along with all audio processing.
Control of the television is accomplished via a CPU embedded within the
MT5389 processor. Below is a list of the key components located on the
Main Board.
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).
MT5389 PROCESSOR
This IC performs the majority of the necessary audio and video processing
on the Main Board.
Analog Video Input Switch: All analog video sources are selected and
A/D converted and scaled (if necessary) to 1920 X 1080p 60HZ resolution.
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 amplier for processing and
amplication.
Audio Processing: Analog audio sources are selected and A/D converted
directly by the MT5389. The audio information is then processed digitally.
Digital audio from the tuner and HDMI sources is also input and processed.
Class D amplier provides the drive for the speakers.
HDMI Input and Switching: The customer can select the HDMI1 through
HDMI4 input. Each HDMI input contains a dedicated EDI NVM (not shown)
to provide display information data to any device connected via the HDMI
inputs.

KDL-40BX450/40BX451/46BX450/46BX451 5
SECTION 1 - FEATURES AND OVERVIEW
LCD PANEL ASSEMBLY
The LCD Panel Assembly includes the LCD Panel, TCON Board, and LED
Backlight system.
The LCD Panel contains the actual liquid crystals, color lters, and
polarizers. The liquid crystals are manipulated by the applied voltage to
pass a specic amount of light - from the backlight - depending on the level
of voltage applied.
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 items.
●LCD Panel
●TCON Board
●Inverter MT 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. To determine if the TCON Board is available as a replacement
part, refer to the LCD Panels Manual.
INVERTER MT BOARD
The inverter receives the unregulated 24V from the Power Supply Board
and generates the required high voltage AC to power the backlight lamps. A
control line to turn on the inverter (backlights on) is used in conjunction with
a dimmer control to vary the light level of the CCFL lamps.

KDL-40BX450/40BX451/46BX450/46BX451 6
OVERVIEW
This chapter provides information regarding the Self Diagnosis feature in
our TVs.
UPDATING THE SOFTWARE
The Self Diagnosis function is designed to provide information regarding
the problem with the TV, however, there are several issues that may be
resolved by updating the TV software to the latest version. Always check
the Sony Authorized Servicer Portal at http://www.sony.com/asp for any
issues that are software related. Most symptoms that are correctable by
software updates involve communications issues with other devices or
minor glitches in the operation of a specic function. Below is a list of some
of the symptoms that may be corrected with a software update:
●Fluctuations in picture brightness
●Intermittent picture freezing or noise
●Problems with certain inputs (especially HDMI)
●Intermittent or distorted audio
●Erratic remote control operation
●TV turns on and off by itself
●Loss of color
●Internet connectivity
●Certain features not working correctly
(photo or video le viewing)
SECTION 2 - TROUBLESHOOTING
Self Diagnosis
Supported model
SELF DIAGNOSIS FUNCTION
Critical voltages and circuit operations are monitored by the CPU on the
Main Board. If an error is detected the Self Diagnosis function in the TV will
force the TV to shut down by the CPU. The monitored circuit in which the
fault occurred will automatically cause the CPU to blink the Standby LED
in groups of repeating sequences. The number of times the Standby LED
blinks indicates the possible cause of the problem.
Not all of the available protect codes are used in every model. For example,
models that don’t have the local dimming feature do not use the 4X blink
error as this circuit is found in models that are backlit with uorescent lamps.
The information in this section provides guidance in locating the possible
component causing the shutdown.
STANDBY LED BLINK COUNT
Standby LED
2 times
5 times
LED ON 0.3 sec.
LED OFF 0.3 sec. LED OFF
3 sec.
LED DISPLAY & BLINK COUNT

KDL-40BX450/40BX451/46BX450/46BX451 7
SECTION 2 - TROUBLESHOOTING
VIEWING THE SELF CHECK DIAGNOSIS HISTORY
When an error is detected, the Self Check screen records the date(s) and
the number of times the error occurred. This is helpful in conrming past
occurrences of an error, and for determining if an error is intermittent when
the customer is not sure what is causing the television to shut down. If the
screen displays a “0”, no error has occurred.
1. Take the TV out of deep Standby mode by pressing
POWER
to
turn on the TV.
2. Press
POWER
to turn the TV back off.
3. Press the following buttons on the Remote Commander within a
second of each other:
DISPLAY Channel 5 Volume +POWER
Sound Adjustment >>
Wide Band Tuning >>
Range Scan… >>
Self diagnosis history >>
Status Information… >>
LVDS Spectrum(%0) <[ 20 ]>
DPMS <[ Off ]>
Low of HPD <[ 5 ]>
TVD_MCDONE_CNT <[ 20 ]>
Demo Special >>
Bypass AVI Info Detec
t
<[ On ]>
Panel Selection <[ 13_FHD_SLCD_40 ]>
UART Selection No Log
SERIAL NUMBER EDIT 5000027
MODEL NAME EDIT KDL-40BX450
[</>]Set [Home] Exit
Service Mode
4. To access the Self diagnosis history page, press until Self
diagnosis history is highlighted, and then press .
Back <<
002 MAIN_ POWER 000
003 DC_ALERT1 000
003 AUDIO_PROT 000
004 BALANCER_ERR 000
005 TCON_ERR 000
005 PANEL_ID_NVM_ERR 000
006 BACKLIGHT_ERR 000
007 TEMP_ERR 000
00001 00036 00001
[Home] Exit
SELF CHEC
K
SAMPLE SELF CHECK DIAGNOSIS PAGE
2X Blink - Main Power Error
A loss of REG12V from the power supply triggers this protect event. The
usual cause is a failure of the main switching supply. In some instances,
excessive loading on the secondary supply lines can cause the switching
regulator to stop, or fail again, if a replacement board is installed.
3X Blink- DC Regulator/Audio Error
The REG 5V and D3.3V source originating on the Main Board is monitored
for low-voltage conditions by the CPU. A failure causing a 3X shutdown
requires replacing the Main Board.
4X Blink – Balancer Error
NOT USED IN THIS MODEL SERIES
5X Blink - TCON Error/Panel Error
The 5X blink protection mode indicates a communications error with the
timing control circuits (TCON Board) has occurred. If the TCON Board is
available for replacement, replace it, if not, replace the LCD Panel Assembly.
In rare cases a loose or defective LVDS cable could also be the cause.

KDL-40BX450/40BX451/46BX450/46BX451 8
SECTION 2 - TROUBLESHOOTING
6X Blink - Backlight Converter System Failure
If the inverter circuits fails to generate high voltage or one or more of the
backlight lamps fails to light, the television will shut down and display this
diagnostics error. Observing for the presence of backlighting is crucial in
determining which component is likely at fault.
If the backlights turn on before the 6X shutdown occurs, it is safe to assume
that the inverter circuits are functioning and one of the lamps failed to ignite.
Replacing the LCD Panel assembly is necessary. If the backlights never
turn on before the 6X shutdown, the Inverter MT Board has failed. If this
board is available for replacement, replace it, if not, replace the LCD Panel
Assembly.
7X Blink - Temperature Failure
A digital thermometer IC located on the Main Board provides a temperature
reading of the chassis and LCD panel. If the temperature exceeds a pre-
determined point the TV will shut down. If this problem occurs immediately
at turn-on, the temperature sensing IC has failed and replacing the main
board is required. If this occurs after the TV has been running for a while,
check for ventilation issues that could cause the TV to run hotter than
normal.
TRIAGE CHART
Use this general Triage Chart to determine what may possibly be causing the error before going out to the customers location.
1. Confirm the symptom from the customer. 5. Chart Color Code
2. Select that symptom from the chart. RED DOT: (Primary) Most likely defective part
3. Bring the primary component listed for that symptom. BLUE Triangle: (Secondary) Possible defective par
t
Power Audio
2X 3X 5X 6X 7X Dead set No
V
ideo
Whole
Screen
Distortion
Isolated
Area
Distortion
No Audio
Main Board 
*▲▲  
Power Supply 
*** 
H Board
Inverter ▲*
LCD Panel ** 
TCON   ▲▲
***Backlight Does NOT Turn ON before TV Shuts
V
ideoProtection Modes
4. Follow the associated flowcharts in the Training Manual to isolate the board.
Board
* TV Immediate Shuts Off After Power ON & 7X
**Backlight Turns ON before TV Shuts Off
*NOTE: REFER TO LCD PANEL SERVICE
MANUAL IN REFERENCE LIBRARY DATABASE
FOR CORRECT REPLACEMENT PARTS BASED
To access the most recent version of the Triage documents for the models listed in this manual, login into the Sony Authorized Servicer Portal at
http://www.sony.com/asp.

KDL-40BX450/40BX451/46BX450/46BX451 9
SECTION 3 - FLOW CHARTS AND DIAGRAMS
BLOCK DIAGRAM
Component/Composite
RF
Composite
HDMI 1
PC HD15
POWER SUPPLY
SWITCH
UNIT
LED
IR RX
LCD PANEL, TCON, &
CCFL BACKLIGHTS
A
H
L
R
ANALOG AUDIO OUT
OPTICAL AUDIO OUT
MT5389
A/V DECODER
A/V PROCESS
TUNER
USB 1
HDMI 2
LVDS
24V & CTL
AC IN
INVERTER
CLASS D
AUDIO
AMP
G10 (40")
G11 (46")
HDMI 3
HDMI 4
Ethernet
USB 2
OVERALL BLOCK DIAGRAM

KDL-40BX450/40BX451/46BX450/46BX451 10
SECTION 3 - FLOW CHARTS AND DIAGRAMS
NO POWER
UNREG24V
BL-ON
GND
BL_ERR
1~5
6~10
11
12
STBY3.3V
AUDIO_12V
AC_OFF_DET
POWER_ON
1
2
3
4
AUDIO_GND
BL_ERR
REG12V_GND
REG12V
5
6, 7
8, 9
10
BL_ON
TCON_12V
DIMMER
N/C
11
12
13
14
TCON_ON
15
AC IN (N)
AC IN (H)
1
2
CN6401
A
N/C
DIMMER
13
14
CN6402
REG 12V
GND
AUDIO_12V
8
5, 7, 9
10
DIMMER
BL_ERR
1
12
CN201
TCON_12V 14
AC_FF_DET
TCON_ON
3
15
BL_ON 13
STBY 3.3V 4
POWER_ON 2
G10 (40")
G11 (46")
INVERTER
CN6101
LCD PANEL &
CCFL BACKLIGHTS
POWER AND CONTROL BLOCK DIAGRAM

KDL-40BX450/40BX451/46BX450/46BX451 11
SECTION 3 - FLOW CHARTS AND DIAGRAMS
*For Part Number information, Refer to “Section 4 - Disassembly/Part Number Information” on page 15.
No Power
Is standby LED
blinking?
No
Yes
No
See
Protection Shutdown
flowchart
Yes
Does red standby
LED on front panel
light?
Press power
button while
monitoring pin 3 of
CN6401 on power
supply board
High (3.3V)
on pin 3?
Yes
No
Main Board*
Power Supply
Board*
High (3.3V)
on pin 2?
Yes
No
Power Supply
Board*
Power Supply
Board*
NO POWER FLOWCHART

KDL-40BX450/40BX451/46BX450/46BX451 12
SECTION 3 - FLOW CHARTS AND DIAGRAMS
STANDBY LED BLINKING
Protect
Shutdown.
Standby LED
Blinking
No
Yes
No
Yes
2X
3X
5X
No
Yes
LCD Panel*
6X
Yes
7X
No
Immediately
After a While
Check room
temperature and
ventilation around
unit
Power Supply
Board*
Main Board*
“SONY” logo
appears before
shutdown?
Yes
No
LCD Panel*
Power Supply
Board*
Main Board*
PROTECTION SHUTDOWN FLOWCHART
*For Part Number information, Refer to “Section 4 - Disassembly/Part Number Information” on page 15.