DOWNLOAD Sony KDL-40EX725 (serv.man2) Service Manual ↓ Size: 11.58 MB | Pages: 51 in PDF or view online for FREE

Model
KDL-40EX725 (serv.man2)
Pages
51
Size
11.58 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LEVEL 3
File
kdl-40ex725-sm2.pdf
Date

Sony KDL-40EX725 (serv.man2) Service Manual ▷ View online

5
KDL-40EX725
KDL-40EX725
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 below.
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, such as the Simpson 229 or RCA 
WT-540A. Follow the manufacturers’ instructions to use these 
instructions.
2.  A battery-operated AC milliampmeter. The Data Precision 245 
digital multimeter is suitable for this job.
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. 
The Simpson’s 250 and Sanwa SH-63TRD are examples of 
passive VOMs that are suitable. Nearly all battery-operated digital 
multimeters that have a 2 VAC range are suitable (see Figure A).
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate 
retaining screw on most AC outlet boxes is also at earth ground. If the 
retaining screw is to be used as your earth ground, verify that it is at 
ground by measuring the resistance between it and a cold-water pipe 
with an ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt 
trouble- light (not a neon 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).
To Exposed Metal
Parts on Set
0.15 µF
Earth Ground
AC
Voltmeter
(0.75V)
Trouble Light
AC Outlet Box
Ohmmeter
Cold-water Pipe
Figure A. Using an AC voltmeter to check AC leakage.
Figure B. Checking for earth ground.
6
KDL-40EX725
KDL-40EX725
SECTION 1:  DIAGRAMS
1-1.  CIRCUIT BOARDS LOCATION
SWITCH
UNIT
HLR2
HEM2
HMS3
TCON
LD
G4
BATV
1-2.  PRINTED WIRING BOARDS AND SCHEMATIC DIAGRAMS INFORMATION
All capacitors are in µF unless otherwise noted. pF : µµF 50WV or 
less are not indicated except for electrolytics and tantalums.
All electrolytics are in 50V unless otherwise specified.
All resistors are in ohms.  k
=1000, M=1000k
Indication of resistance, which does not have one for rating  
electrical power, is as follows: 
Pitch : 5mm 
    Rating 
electrical 
power 
1
/
 4 
W
1
/
 4 
W in resistance, 
1
/
10 
W and 
1
/
16 
W in chip resistance.
: nonflammable resistor
 : fusible resistor
 : internal component
 : panel designation and adjustment for repair
 : earth ground
 : earth-chassis
All variable and adjustable resistors have characteristic curve B,  
unless otherwise noted.
Readings are taken with a color-bar signal input.
Readings are taken with a 10M
 digital multimeter.
Voltages are DC with respect to ground unless otherwise noted.
Voltage variations may be noted due to normal production 
tolerances.
All voltages are in V.
S : Measurement impossibility.
: B+line.
: B-line.  (Actual measured value may be different).
: signal path. (RF)
Circled numbers are waveform references.
The components identified by shading and 
!
 symbol are critical for safety. Replace 
only with part number specified. 
The symbol 
 indicates a fast operating fuse and is displayed on the component 
side of the board. Replace only with fuse of the same rating as marked.
NOTE: The components identified by a red outline and a   mark contain confidential 
information. Specific instructions must be adhered to whenever these components 
are repaired and/or replaced. 
See Appendix A: Encryption Key Components in the back of this manual. 
7
KDL-40EX725
KDL-40EX725
G
D
S
B1 E1
C2
B2 C1
E2
2
3
4
5
6
7
8
9
1
G
D
S
B2 E2
C1
B1 C2
E1
B2 E2
C1
B1 C2
E1
B2 E2
C1
B1 C2
E1
B1 E1
E2
C1(B2)
C2
B1
E2
C1
C2
(B2)
E1
(B2)
E1
E2
B1
C2
C1
B1
E1
C2
B2
C1
E2
G
S
S
D
G
D
B1
E1
C2
B2
C1
E2
B1
E2
C2
C1(B2)
E2
B1
C1
C2
E1(B2)
C2
B1
C1
E2
E1(B2)
C2
B1
C1
E2
B2
E1
C2
Ver.1.6
Transistor
(FET)
Transistor
Transistor
Transistor
Transistor
Transistor
Transistor
Transistor
Transistor
Transistor
Discrete semiconductor
(Chip semiconductors that are not actually used are included.)
Diode
Diode
Diode
Diode
Diode
Diode
Diode
Diode
Diode
Diode
Source
Source
Anode
Anode
(NC)
(NC)
Cathode
Anode
Cathode
Common
Cathode
Cathode
Common
Cathode
Cathode
Common
Common
Common
Common
Cathode
Anode
Base
Emitter
Collector
Base
Emitter
Collector
Drain
Gate
Gate
Drain
Device
Printed symbol
Terminal name
Circuit
Terminal name of semiconductors in silk screen
printed circuit (    )
Anode
Anode
Anode Cathode
Anode Anode
Cathode
Transistor
(FET)
Transistor
(FET)
Emitter
Collector
Base
Transistor
Source
Gate
Drain
Cathode
Anode
Anode
Cathode
Anode
Anode
*
18
11
17
16
15
14
13
12
10
21
20
19
23
22
REFERENCE INFORMATION 
RESISTOR 
: RN  
METAL FILM
: RC 
SOLID
: FPRD  NONFLAMMABLE CARBON
: FUSE  NONFLAMMABLE FUSIBLE
: RW 
NONFLAMMABLE WIREWOUND
: RS 
NONFLAMMABLE METAL OXIDE
: RB 
NONFLAMMABLE CEMENT
 
ADJUSTMENT RESISTOR
COIL 
: LF-8L  MICRO INDUCTOR
CAPACITOR
: TA 
TANTALUM
: PS 
STYROL
: PP 
POLYPROPYLENE
: PT 
MYLAR
: MPS 
METALIZED POLYESTER
: MPP 
METALIZED POLYPROPYLENE
: ALB 
BIPOLAR
: ALT 
HIGH TEMPERATURE
: ALR 
HIGH RIPPLE
KDL-40EX725
KDL-40EX725
1-3.  BLOCK DIAGRAM
BATV
X-Reality Processor
TV Microprocessor
Video Processing
HDMI Processing
HDCP Processing
IP (Image Processor)
Scan Converter (Scalar)
Audio Processing
Video Switcher
HDMI Switcher
ATSC/NTSC Tuner
Temperature Sensor
Audio Output Amplifier
Control
LVDS 
Keys
Power/
SIRCS
LCD Panel Assembly
LCD PANEL
Switch Unit
LEDs
IR Sensor
Light Level
HLR2
Power
G4 Board
LCD Panel
R
L
RF Input
Component/Composite
Composite
PC Input
4 HDMI Inputs
Optical Digital Audio Output
LED
Backlight System
TCON/HFR
(120Hz)
AC 
Input
2 USB 2.0
Motion Sensor
RJ45 Ethernet
HMS3
Headphone/Analog Audio Output
Power +
Power -
3D Emitter
HEM2
Main Power Supply
Standby Power Supply
AC Relay
LED Backlight Power Supply 
LED Power
Power & 
Control
Control
NOTE: The LD-Board is NOT included 
in the LCD Panel Assembly
Power Key
Function Keys
LD
FIGuRE 3-1.  OVERALL BLOCK DIAGRAM
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