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Chassis AL29NO, AL40NO Model LTM295W, LTM405W
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CONFIDENTIAL
LCD-TV
Chassis Model
AL29NO LTM295W
AL40NO LTM405W
SERVICE Manual
LCD-TV CONTENTS
1. Precautions
2. Product Specifications
3. Disassembly & Reassembly
4. Alignment & Adjustments
5. Troubleshooting
6. Exploded View & Parts List
7. Electrical Parts List
8. Block Diagram
9. Wiring Diagram
10. Schematic Diagrams
11. Panel Description
CONFIDENTIAL
1 Precautions
Follow these safety, servicing and ESD precautions to prevent damage and to protect against potential hazards such as
electrical shock.
1-1 Safety Precautions
1-1-1 Warnings
1. For continued safety, do not attempt to modify the
(READING SHOULD
circuit board. NOT BE ABOVE 0.5mA)
2. Disconnect the AC power and DC Power Jack
before servicing. DEVICE
LEAKAGE
CURRENT
UNDER TESTER
1-1-2 Servicing the LCD Monitor TEST
TEST ALL
EXPOSED METAL
1. When servicing the LCD Monitor disconnect the SURFACES
AC line cord from the AC outlet.
2-WIRE CORD
2. It is essential that service technicians have an
accurate voltage meter available at all times. Check
the calibration of this meter periodically. ALSO TEST WITH
PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED) EARTH
1-1-3 Fire and Shock Hazard GROUND
Before returning the monitor to the user, perform the Figure 1-1. Leakage Current Test Circuit
following safety checks:
1. Inspect each lead dress to make certain that the 4. With the unit completely reassembled, plug the AC
leads are not pinched or that hardware is not line cord directly into a 120V AC outlet. With the
lodged between the chassis and other metal parts in unit's AC switch first in the ON position and then
the monitor. OFF, measure the current between a known earth
2. Inspect all protective devices such as nonmetallic ground (metal water pipe, conduit, etc.) and all
control knobs, insulating materials, cabinet backs, exposed metal parts, including: metal cabinets,
adjustment and compartment covers or shields, screwheads and control shafts. The current
isolation resistor-capacitor networks, mechanical measured should not exceed 0.5 milliamp. Reverse
insulators, etc. the power-plug prongs in the AC outlet and repeat
3. Leakage Current Hot Check (Figure 1-1): the test.
WARNING:
Do not use an isolation transformer during this test. 1-1-4 Product Safety Notices
Use a leakage current tester or a metering system
Some electrical and mechanical parts have special
that complies with American National Standards
safety-related characteristics which are often not
Institute (ANSI C101.1, Leakage Current for evident from visual inspection. The protection they give
Appliances), and Underwriters Laboratories (UL may not be obtained by replacing them with
Publication UL1410, 59.7). components rated for higher voltage, wattage, etc. Parts
that have special safety characteristics are identified by
! on schematics and parts lists. A substitute
replacement that does not have the same safety
characteristics as the recommended replacement part
might create shock, fire and / or other hazards. Product
safety is under review continuously and new
instructions are issued whenever appropriate.
LTM295W/LTM405W 1-1
1 Precautions
CONFIDENTIAL
1-2 Servicing Precautions
WARNING: An electrolytic capacitor installed with the wrong polarity might explode.
Caution: Before servicing units covered by this service manual, read and follow the Safety Precautions
section of this manual.
Note: If unforeseen circumstances create conflict between the following servicing precautions and any of the
safety precautions, always follow the safety precautions.
1-2-1 General Servicing Precautions
1. Always unplug the unit's AC power cord from the 4. Check the insulation between the blades of the AC
AC power source and disconnect the DC Power plug and accessible conductive parts (examples:
Jack before attempting to: metal panels, input terminals and earphone jacks).
(a) remove or reinstall any component or assembly, 5. Insulation Checking Procedure: Disconnect the
(b) disconnect PCB plugs or connectors, (c) connect power cord from the AC source and turn the power
a test component in parallel with an electrolytic switch ON. Connect an insulation resistance meter
capacitor. (500 V) to the blades of the AC plug.
2. Some components are raised above the printed The insulation resistance between each blade of the
circuit board for safety. An insulation tube or tape AC plug and accessible conductive parts (see
is sometimes used. The internal wiring is above) should be greater than 1 megohm.
sometimes clamped to prevent contact with
6. Always connect a test instrument's ground lead to
thermally hot components. Reinstall all such
the instrument chassis ground before connecting
elements to their original position.
the positive lead; always remove the instrument's
3. After servicing, always check that the screws, ground lead last.
components and wiring have been correctly
reinstalled. Make sure that the area around the
serviced part has not been damaged.
1-3 Electrostatically Sensitive Devices (ESD) Precautions
Some semiconductor (solid state) devices can be easily damaged by static electricity. Such components are commonly
called Electrostatically Sensitive Devices (ESD). Examples of typical ESD are integrated circuits and some field-effect
transistors. The following techniques will reduce the incidence of component damage caused by static electricity.
1. Immediately before handling any semiconductor 6. Do not remove a replacement ESD from its
components or assemblies, drain the electrostatic protective package until you are ready to install it.
charge from your body by touching a known earth Most replacement ESDs are packaged with leads
ground. Alternatively, wear a discharging wrist- that are electrically shorted together by conductive
strap device. To avoid a shock hazard, be sure to foam, aluminum foil or other conductive materials.
remove the wrist strap before applying power to 7. Immediately before removing the protective
the monitor. material from the leads of a replacement ESD,
2. After removing an ESD-equipped assembly, place it touch the protective material to the chassis or
on a conductive surface such as aluminum foil to circuit assembly into which the device will be
prevent accumulation of an electrostatic charge. installed.
3. Do not use freon-propelled chemicals. These can Caution: Be sure no power is applied to the
generate electrical charges sufficient to damage chassis or circuit and observe all
ESDs. other safety precautions.
4. Use only a grounded-tip soldering iron to solder or
desolder ESDs. 8. Minimize body motions when handling
unpackaged replacement ESDs. Motions such as
5. Use only an anti-static solder removal device. Some brushing clothes together, or lifting your foot from
solder removal devices not classified as "anti-static" a carpeted floor can generate enough static
can generate electrical charges sufficient to damage electricity to damage an ESD.
ESDs.
1-2 LTM295W/LTM405W
CONFIDENTIAL
2 Product Specifications
2-1 Specifications
Description
Item
LTM295W LTM405W
LCD Panel TFT-LCD panel, RGB vertical stripe, normally black TFT-LCD panel, RGB vertical stripe, normally black
transmissive, (29 -Inch) viewable, 0.4935 mm pixel pitch transmissive, (40-Inch) viewable, 0.6735 mm pixel pitch
Scanning Frequency Horizontal : 30 KHz ~ 60 KHz
Vertical : 56 Hz ~ 75 Hz
Display Colors 16,777,216 Million colors
Maximum Resolution Horizontal : 1280 Pixels
Vertical : 768 Pixels
Input Video Signal Analog, 0.7 Vp-p ± 5% positive at 75 ,
internally terminated
Input Sync Signal Type : Seperate H/V sync, Composite H/V, Sync-on-Green
Level : TTL level
AC power voltage & Frequency AC 90 ~ 240V 60 Hz/50 Hz ± 3 Hz, DC 28V / 8A
Power Consumption 160W (max) 220W (max)
Dimensions
Unit (W x D x H) 29.9 x 7.7 x 22.4 Inches (759.6 x 195.0 x 568.5 mm) 39.6 x 11.8 x 29.4 Inches (1006.0 x 300.0 x 746.5 mm)
Carton (W x D x H) 37.8 x 7.7 x 22.4 Inches (961.2 x 195.0 x 568.5 mm) 49.1 x 11.8 x 29.4 Inches (1247.6 x 300.0 x 746.5 mm)
Weight (Net / Gross) 18.0 kg (39.682 lbs) 28.0 kg ( 61.715 lbs)
Environmental Considerations Operating Temperature : 50°F ~ 104°F (10°C ~ 40°C)
Humidity : 10 % ~ 80 %
Storage Temperature : -4°F ~ 113°F (-20°C ~ 45°C)
Humidity : 5 % ~ 95 %
Color NTSC-M
TV System
Sound BTSC, A2 STEREO, EIAJ
Antena Input 75, Coaxial Cable
Sound Characteristics ·Max Internal speaker Out : Right c 10 W / Leftc 10 W
·Bass control Range : -6 ± -12dB ~ +6 ± 12dB
·TREBLE control Range : -10 ± -12dB ~ +10 ± 12dB
·Output frequency : RFc 80 Hz~15 KHz / A/Vc 80 Hz~20 KHz
·Line out : RFc 80 Hz~15 KHz / A/Vc 80 Hz~20 KHz
·SyncMaster LTM295W/LTM405W comply with SWEDAC (MPRII) recommendations for reduced electromagnetic fields.
·Designs and specifications are subject to change without prior notice.
LTM295W/LTM405W 2-1
CONFIDENTIAL
2-2 Pin Assignments
Pin No. 30 Pin Signal Cable (DVI Analog) Pin No. 30 Pin Signal Cable (DVI Analog)
1 RX2+ 16 GND
2 RX2- 17 Check · D-Sub
3 GND 18 GND
4 RX1+ 19 DDC_5V
5 RX1- 20 DDC_5V
6 GND 21 GND
7 RX0+ 22 V/Sync
8 RX0- 23 GND
9 GND 24 H/Sync
10 RXC+ 25 GND
11 RXC- 26 Blue
12 GND 27 GND
13 DDC (Clock) 28 Green
14 DDC (Data) 29 GND
15 GND 30 Red
2 Product Specifications
CONFIDENTIAL
2-3 Timing Chart
This section of the service manual describes the timing that the computer industry recognizes as standard
for computer-generated video signals.
Table 2-1 Timing Chart
Mode DTV/ DTV/
VGA3/60 Hz VGA/72 Hz VGA/75 Hz VGA/85 Hz MAC/60 Hz MAC/66 Hz SVGA/56 Hz SVGA/60 Hz SVGA/72 Hz
59.94 Hz 59.94 Hz
640 x 480 640 x 480 640 x 480 640 x 480 640 x 480 640 x 480 800 x 600 800 x 600 800 x 600
Timing 1280 x 720 1920 x 1080
fH (kHz) 44.955 33.716 31.5 37.9 37.5 43.3 31.5 35.0 35.2 37.9 48.1
A µsec 1650 2200 800 832 840 832 800 864 1024 1056 1040
B µsec 40 44 96 40 64 56 96 64 72 128 120
C µsec 70 44 40 120 120 80 48 96 128 88 64
D µsec 1280 1920 640 640 640 640 640 640 800 800 800
E µsec 260 192 8 16 16 56 16 64 24 40 56
fV (Hz) 59.94 59.94 60.0 72.8 75.0 85.0 60.0 66.7 56.3 60.3 72.2
O msec 750 1125 525 520 500 509 525 525 625 628 666
P msec 5 15 2 3 3 3 2 3 2 4 6
Q msec 20 2 25 20 16 25 33 39 22 23 23
R msec 720 1080 480 480 480 480 480 480 600 600 600
S msec 5 5 2 1 1 1 10 3 1 1 37
Clock
Freq. 74.176 74.176 25.175 31.500 31.500 36.000 25.175 30.240 36.000 40.000 50.000
(MHz)
Polarity
H.Sync /+ /+ Negative Negative Negative Negative Negative Negative /+ Positive Positive
V.Sync /+ /+ Negative Negative Negative Negative Negative Negative /+ Positive Positive
Remark Separate Separate Separate Separate Separate Separate Separate Separate Separate Separate Separate
Separate Sync
Horizontal Vertical
Video
Video Video
Video
CC DD E E Q Q RR S S
Sync
Sync Sync
Sync
B
B PP
AA O O
A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width
C : Back porch D : Active time Q : Back porch R : Active time
E : Front porch S : Front porch
LTM295W/LTM405W 2-3
2 Product Specifications
CONFIDENTIAL
Table 2-2 Timing Chart (continued)
Mode
SVGA/75 Hz SVGA/85 Hz MAC/74 Hz XGA/60 Hz XGA/70 Hz XGA/75 Hz XGA/85 Hz MAC/60 Hz MAC/74 Hz VESA/75 Hz MAC/75 Hz
800 x 600 800 x 600 832 x 624 1024 x 768 1024 x 768 1024 x 768 1024 x 768 1024 x 768 1024 x 768 1152 x 864 1152 x 870
Timing
fH (kHz) 46.9 53.7 49.7 48.4 56.5 60.0 68.7 48.8 60.2 67.5 68.7
A µsec 1056 1048 1152 1344 1328 1312 1376 1312 1328 1600 1456
B µsec 80 64 64 136 136 96 96 96 96 128 128
C µsec 160 152 224 160 144 176 208 128 176 256 144
D µsec 800 800 832 1024 1024 1024 1024 1024 1024 1152 1152
E µsec 16 32 32 24 24 16 48 64 32 64 32
fV (Hz) 75.0 85.1 74.6 60.0 70.1 75.0 85.0 60.0 74.9 75.0 75.1
O msec 625 631 667 806 806 800 808 813 804 900 915
P msec 3 3 3 6 6 3 3 6 3 3 3
Q msec 21 27 39 29 29 28 36 33 30 32 39
R msec 600 600 624 768 768 768 768 768 768 864 870
S msec 1 1 1 3 3 1 1 6 3 1 3
Clock
Freq. 49.500 56.250 57.284 65.000 75.000 78.750 94.500 64.000 80.000 108.000 100.000
(MHz)
Polarity
H.Sync Positive Positive Negative Negative Negative Positive Positive Negative Negative Positive Negative
V.Sync Positive Positive Negative Negative Negative Positive Positive Negative Negative Positive Negative
Remark Separate Separate Separate Separate Separate Separate Separate Separate Separate Separate Separate
Separate Sync
Horizontal Vertical
Video
Video Video
Video
CC DD E E Q Q RR S S
Sync
Sync Sync
Sync
B
B PP
AA O O
A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width
C : Back porch D : Active time Q : Back porch R : Active time
E : Front porch S : Front porch
2-4 LTM295W/LTM405W
2 Product Specifications
CONFIDENTIAL
Table 2-3 Timing Chart (continued)
Mode
SUN/66 Hz SUN/76 Hz SXGA/60 Hz NCD/70 Hz HP/72 Hz SXGA/75 Hz SUN/76 Hz
1152 x 900 1152 x 900 1280 x 1024 1280 x 1024 1280 x 1024 1280 x 1024 1280 x 1024
Timing
fH (kHz) 61.8 71.7 64.0 74.4 78.1 80.0 81.1
A µsec 1528 1472 1688 1680 1728 1688 1664
B µsec 128 96 112 160 192 144 64
C µsec 208 208 248 208 192 248 288
D µsec 1152 1152 1280 1280 1280 1280 1280
E µsec 40 16 48 32 64 16 32
fV (Hz) 66.0 76.0 60.0 70.0 72.0 75.0 76.1
O msec 937 943 1066 1063 1085 1066 1066
P msec 4 8 3 3 3 3 8
Q msec 31 33 38 36 55 38 32
R msec 900 900 1024 1024 1024 1024 1024
S msec 2 2 1 0 3 1 2
Clock
Frequency 94.500 105.561 108.000 125.000 135.000 135.000 135.000
(MHz)
Polarity
H.Sync /+ Negative Positive Negative Negative Positive Negative
V.Sync /+ Negative Positive Negative Negative Positive Negative
Remark Separate Separate Separate Separate Separate Separate Separate
Separate Sync
Horizontal Vertical
Video
Video Video
Video
CC DD E E Q Q RR S S
Sync
Sync Sync
Sync
B
B PP
AA O O
A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width
C : Back porch D : Active time Q : Back porch R : Active time
E : Front porch S : Front porch
LTM295W/LTM405W 2-5
2 Product Specifications
CONFIDENTIAL
Table 2-4 Timing Chart (continued)
Mode
UXGA/60Hz UXGA/65Hz UXGA/70Hz NCD/64Hz SUN/66 Hz WUXGA2/60 Hz
1600 x 1200 1600 x 1200 1600 x 1200 1600 x 1200 1600 x 1200 1920 x 1200
Timing
fH (kHz) 75 81.25 87.5 80.038 89.286 74.52
A µsec 2160 2160 2160 2124 2240 2592
B µsec 192 192 192 160 256 208
C µsec 304 304 304 308 368 336
D µsec 1600 1600 1600 1600 1600 1920
E µsec 64 64 64 56 16 128
fV (Hz) 60 65 70 64.443 66.931 60
O msec 1250 1250 1250 1242 1334 1242
P msec 3 3 3 3 10 3
Q msec 46 46 46 38 44 38
R msec 1200 1200 1200 1200 1200 1200
S msec 1 1 1 1 80 1
Clock
Frequency 162.000 175.500 189.000 170.000 200.000 193.156
(MHz)
Polarity
H.Sync /+ /+ /+ /+ /+ Negative
V.Sync /+ /+ /+ /+ /+ Positive
Remark Separate Separate Separate Separate Separate Separate
Separate Sync
Horizontal Vertical
Video
Video Video
Video
CC DD E E Q Q RR S S
Sync
Sync Sync
Sync
B
B PP
AA O O
A : Line time total B : Horizontal sync width O : Frame time total P : Vertical sync width
C : Back porch D : Active time Q : Back porch R : Active time
E : Front porch S : Front porch
2-6 LTM295W/LTM405W
2 Product Specifications
CONFIDENTIAL
2-4 DTV Timing Chart
Table 2-5 DTV Timing chart
Timing No. 1 2 3
Originator 274M 296M 293M
Mode Name 1080i/60iHz 720p/60Hz 480p/60Hz
Resolution (HxV) 1920x1080 1280x720 720x483
HORIZONTAL
Frequency 33.750kHz 45.000kHz 31.469kHz
Total time 29.630µs 22.222µs 31.778µs
Border (L / R) 0.000µs 0.000µs 0.000µs
Data time 25.859µs 17.239µs 26.667µs
Front porch 0.593µs 0.943µs 0.593µs
Sync. width 0.593µs 0.539µs 2.333µs
Back porch 2.586µs 3.502µs 2.185µs
Sync. polarity - - -
VERTICAL
Frequency 30Hz 60Hz 60Hz
Total time 33.333ms 16.667ms 16.683ms
Border (T / B) 0.000ms 0.000ms 0.000ms
Data time - 16.000ms 15.349ms
Front porch 0.059ms 0.111ms 0.191ms
Sync. width 0.148ms 0.111ms 0.191ms
Back porch 0.444ms 0.444ms 0.953ms
Sync. polarity - - -
Dot Clock 75MHz 75MHz 27MHz
LTM295W/LTM405W 2-7
2 Product Specifications
CONFIDENTIAL
Memo
2-8 LTM295W/LTM405W
CONFIDENTIAL
3 Disassembly and Reassembly
This section of the service manual describes the disassembly and reassembly procedures for the
LTM295W/LTM405W monitor.
WARNING: This monitor contains electrostatically sensitive devices. Use caution when handling
these components.
3-1 Disassembly
Cautions:1. Disconnect the monitor from the power source before disassembly.
2. Follow these directions carefully; never use metal instruments to pry apart the cabinet.
1. Remove 4 screws of the cover rear.
2. Remove the stand from LCD-TV.
LTM295W/LTM405W 3-1
3 Disassembly and Reassembly
CONFIDENTIAL
3. Remove 4 screws of the cover rear.
4. Pull the cover rear.
3-2 Reassembly
Reassembly procedures are in the reverse order of Disassembly procedures.
3-2 LTM295W/LTM405W
CONFIDENTIAL
4 Alignments and Adjustments
This section of the service manual explains how to use the DDC JIG to adjust the black, red, green, and blue
levels of the FPD when you replace the AD Board, and how to update the microprocessor when you
change the Panel or Lamp(s).
4-1 General Alignment Instuction
1. Usually, a color TV-VCR needs only slight touch-up adjustment upon installation.
Check the basic characteristics such as height, horizontal and vertical sync.
2. Use the specified test equipment or its equivalent.
3. Correct impedance matching is essential.
4. Avoid overload. Excessive signal from a sweep generator might overload the front-end
of the TV. When inserting signal markers,do not allow the marker generator to distort
test result.
5. Connect the TV only to an DC power source with voltage and frequency as specified on
the backcover nameplate.
6. Do not attempt to connect or disconnect any wire while the TV is turned on. Make sure
that the power cord is disconnected before replacing any parts.
7. To protect aganist shock hazard,use an isolation transform.
LTM295W/LTM405W 4-1
4 Alignments and Adjustments
CONFIDENTIAL
Memo
4-2 LTM295W/LTM405W
CONFIDENTIAL
5 Troubleshooting
5-1 No Power
29":Does proper DC 28 V appear
at DC jack connected to CN28? No
Check SMPS PCB and Adapter.
40":Does proper DC 28 V appear
at DC jack connected to CN29?
Yes
Does proper DC 5 V appear at No
Check CN201 and related circuit.
Pin 17 of CN201?
Yes
Does proper DC 5 V appear at No
Check IC952, IC955 and IC 958.
Pin 2 of IC952, IC955 and IC 958?
Yes
Does proper DC 3.3 V No
appear at Pin 2 of IC953, Check IC953, IC954, IC956 and IC957.
IC954, IC956 and IC957?
Yes
Does proper DC 2.5 V appear at No
Check IC961 and IC964.
Pin 2 of IC961 and IC964?
Yes
Check IC963, IC906 and IC905.
LTM295W/LTM405W 5-1
5 Troubleshooting
CONFIDENTIAL
5-2 No Video (CVBS, S-Video)
Power indicator is green
Does the signal appear at No
Check IC1.
Pin 5, 9, 11 and 36 of IC1?
Yes
Does the clock pulse appear at No
Check IC302 and related circuit.
Pin 6, 13 and Pin 69, 70 of IC302?
Yes
Does the colck pluse No
appear at R812, R813 and Check related circuit of IC801.
H/V Sync pulse of IC801?
Yes
Replace LCD Panel.
5-2 LTM295W/LTM405W
5 Troubleshooting
CONFIDENTIAL
5-3 No Picture (PC Signal [Analog])
No
Check Pin 22 and 24 of CN201. Check CN201 and related circuit.
Yes
No
Check Pin 66 and 67 of CN203. Check IC203 and related circuit.
Yes
Does the colck pluse No
appear at R619, R621 and Check IC603 and related circuit.
H/V Sync pulse of IC603?
Yes
IC901 and IC903 and replace it.
LTM295W/LTM405W 5-3
5 Troubleshooting
CONFIDENTIAL
5-4 No Sound (RF, PC, Video, Component)
Does the signal appear at No
Pin 47, 48, 50, 51, 53, 54, 56, Check IC503 and related circuit.
57 and 67 of IC503?
Yes
No
Check Pin 10 and 13 of IC504? Check IC504 and related circuit Q501.
Yes
Does the signal appear at No
Replace L502, L503, L504 and L505.
L502, L503, L504 and L505?
Yes
29":Check Speaker and CN2.
40":Check Speaker and CN2.
5-4 LTM295W/LTM405W
5 Troubleshooting
CONFIDENTIAL
5-5 No Picture (DTV)
Power inductor is green.
Yes
29":Does the signal appear at
Pin 16, 18 and 20 of CN103? No Check related circuit and
40":Does the signal appear at input signal of connector.
Pin 16, 18 and 20 of CN3?
Yes
Dose the signal appear at No
Check IC403 and related circuit.
Pin 15, 19 and 21 of IC403?
Yes
Dose the signal appear at No
Check IC404 and related circuit.
Pin 43, 48 and 54 of IC404?
Yes
Check IC801 and related circuit.
LTM295W/LTM405W 5-5
5 Troubleshooting
CONFIDENTIAL
Memo
5-6 LTM295W/LTM405W
CONFIDENTIAL
6 Exploded View and Parts List
6-1 LTM295W
LTM295W/LTM405W 6-1
6 Exploded View & Parts List
CONFIDENTIAL
6-2 LTM405W
6-2 LTM295W/LTM405W
MDIN 1 00 Scaler
MUX
(HD Deinterlacer) Jack Asm
LTM295W/LTM405W
8 Block Diagram
Scaler
Jack Asm ALTERA
EPA3032
LVDS
VSP9437