JVC LT-26X506/S User manual

SERVICE MANUAL
COPYRIGHT © 2005 Victor Company of Japan, Limited No.YA333
2005/10
LCD FLAT TELEVISION
YA333200510 LT-26X506/S,
LT-32X506/S/L
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-13
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
BASIC CHASSIS
FU

1-2 (No.YA333)
SPECIFICATION
Design & specifications are subject to change without notice.
Items Contents
LT-26X506 LT-32X506
Dimensions ( W ×H ×D )
68.6 cm × 52.7 cm × 30.8 cm
(27-1/8"
× 20-3/4" × 12-1/4")[Includedstand]
68.6 cm × 47.4 cm × 12.2 cm
(27-1/8" × 18-3/4" × 4-7/8") [TV only]
82.0 cm
× 60.4 cm × 30.8 cm
(32-3/8"
× 23-7/8" × 12-1/4")[Includedstand]
82.0 cm × 55.1 cm × 12.7 cm
(32-3/8" × 21-3/4" × 5") [TV only]
Mass 16 kg (35.2 lbs) [Included stand]
12.5 kg (27.5 lbs) [TV only] 20 kg (44.0 lbs) [Included stand] 16.5 kg (36.3 lbs) [TV only]
Power Input AC120 V, 60 Hz
Power Consumption 124 W 186 W
TV RF System CCIR (M)
Color System NTSC
Sound System BTSC (Multi Channel Sound)
Teletext System Closed Caption (T1 - T4 / CC1 - CC4)
TV Receiving Channels
and Frequency VHF low VHF high
UHF
CATV
02ch - 06ch: 54 MHz - 88 MHz
07ch - 13ch: 174 MHz - 216 MHz
14ch - 69ch: 470 MHz - 806 MHz
54MHz - 804 MHz
Low Band: 02 - 06
High Band: 07 - 13
Mid Band: 14 - 22
Super Band: 23 - 36
Hyper Band: 37 - 64
Ultra Band: 65 - 94, 100 - 135
Sub Mid Band: 01, 96 - 99
TV / CATV Total Channel
181 Channels
[Reception of channel A-5 ("95" of the TV set’s on-screen CABLE channel) is
recommended for your TV set.]
Intermediate Frequency Video IF
Sound IF 45.75 MHz 41.25 MHz (4.5 MHz)
Color Sub Carrier 3.58 MHz
LCD panel 26V-inch wide aspect (16 : 9) 32V-inch wide aspect (16 : 9)
Screen Size
Diagonal : 65 cm (H: 57.6 cm × V: 32.4 cm) Diagonal : 80 cm (H: 69.7 cm × V: 39.2 cm)
Display Pixels Horizontal : 1366 dots ×Vertical : 768 dots (W-XGA)
Audio Power Output 5 W + 5 W
Speaker 6.6 cm, round type ×2 (Oblique corn)
Antenna terminal (VHF/UHF) F-type connector, 75 Ωunbalanced, coaxial
Video / Audio input
[INPUT-1/2/3] Component Video [INPUT-1]
1125i / 750p
525p / 525i
S-Video
[INPUT-1/2]
Video
Audio
RCA pin jack ×3
Y : 1 V (p-p) (Sync signal: 0.35V(p-p), 3-value sync.), 75 Ω
Pb/Pr : ±0.35V(p-p), 75 Ω
Y : 1 V (p-p), Positive (Negative sync provided), 75 Ω
Cb/Cr : 0.7V(p-p), 75 Ω
Mini-DIN 4 pin ×2
Y: 1 V (p-p), Positive (Negative sync provided), 75 Ω
C: 0.286V (p-p) (Burst signal), 75 Ω
1 V (p-p), Positive (Negative sync provided), 75 Ω, RCA pin jack ×3
500 mV (rms), High impedance, RCA pin jack ×6
Headphone 3.5 mm stereo mini jack ×1
Remote Control Unit RM-C1271G (AA/R6 dry cell battery ×2)

(No.YA333)1-3
SECTION 1
PRECAUTION
1.1 SAFETY PRECAUTIONS
(1) The design of this product contains special hardware,
many circuits and components specially for safety
purposes. For continued protection, no changes should be
made to the original design unless authorized in writing by
the manufacturer. Replacement parts must be identical to
those used in the original circuits. Service should be
performed by qualified personnel only.
(2) Alterations of the design or circuitry of the products should
not be made. Any design alterations or additions will void
the manufacturer's warranty and will further relieve the
manufacturer of responsibility for personal injury or
property damage resulting therefrom.
(3) Many electrical and mechanical parts in the products have
special safety-related characteristics. These
characteristics are often not evident from visual inspection
nor can the protection afforded by them necessarily be
obtained by using replacement components rated for
higher voltage, wattage, etc. Replacement parts which
have these special safety characteristics are identified in
the parts list of Service manual. Electrical components
having such features are identified by shading on the
schematics and by ( ) on the parts list in Service
manual. The use of a substitute replacement which does
not have the same safety characteristics as the
recommended replacement part shown in the parts list of
Service manual may cause shock, fire, or other hazards.
(4) Don't short between the LIVE side ground and
ISOLATED (NEUTRAL) side ground or EARTH side
ground when repairing.
Some model's power circuit is partly different in the GND.
The difference of the GND is shown by the LIVE : ( ) side
GND, the ISOLATED (NEUTRAL) : ( ) side GND and
EARTH : ( ) side GND.
Don't short between the LIVE side GND and ISOLATED
(NEUTRAL) side GND or EARTH side GND and never
measure the LIVE side GND and ISOLATED (NEUTRAL)
side GND or EARTH side GND at the same time with a
measuring apparatus (oscilloscope etc.). If above note will
not be kept, a fuse or any parts will be broken.
(5) When service is required, observe the original lead dress.
Extra precaution should be given to assure correct lead
dress in the high voltage circuit area. Where a short circuit
has occurred, those components that indicate evidence of
overheating should be replaced. Always use the
manufacturer's replacement components.
(6) Isolation Check (Safety for Electrical Shock Hazard)
After re-assembling the product, always perform an
isolation check on the exposed metal parts of the cabinet
(antenna terminals, video/audio input and output terminals,
Control knobs, metal cabinet, screw heads, earphone jack,
control shafts, etc.) to be sure the product is safe to operate
without danger of electrical shock.
a) Dielectric Strength Test
The isolation between the AC primary circuit and all metal
parts exposed to the user, particularly any exposed metal
part having a return path to the chassis should withstand a
voltage of 3000V AC (r.m.s.) for a period of one second. (.
. . . Withstand a voltage of 1100V AC (r.m.s.) to an
appliance rated up to 120V, and 3000V AC (r.m.s.) to an
appliance rated 200V or more, for a period of one second.)
This method of test requires a test equipment not generally
found in the service trade.
b) Leakage Current Check
Plug the AC line cord directly into the AC outlet (do not use
a line isolation transformer during this check.). Using a
"Leakage Current Tester", measure the leakage current
from each exposed metal part of the cabinet, particularly
any exposed metal part having a return path to the chassis,
to a known good earth ground (water pipe, etc.). Any
leakage current must not exceed 0.5mA AC (r.m.s.).
However, in tropical area, this must not exceed 0.2mA AC
(r.m.s.).
Alternate Check Method
Plug the AC line cord directly into the AC outlet (do not
use a line isolation transformer during this check.). Use
an AC voltmeter having 1000Ωper volt or more
sensitivity in the following manner. Connect a 1500Ω
10W resistor paralleled by a 0.15µF AC-type capacitor
between an exposed metal part and a known good earth
ground (water pipe, etc.). Measure the AC voltage
across the resistor with the AC voltmeter. Move the
resistor connection to each exposed metal part,
particularly any exposed metal part having a return path
to the chassis, and measure the AC voltage across the
resistor. Now, reverse the plug in the AC outlet and
repeat each measurement. Any voltage measured must
not exceed 0.75V AC (r.m.s.). This corresponds to
0.5mA AC (r.m.s.).
However, in tropical area, this must not exceed 0.3V AC
(r.m.s.). This corresponds to 0.2mA AC (r.m.s.).
AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)
PLACE THIS PROBE
ON EACH EXPOSED
METAL PART
1500 10W
0.15 F AC-TYPE
GOOD EARTH GROUND

1-4 (No.YA333)
1.2 INSTALLATION
1.2.1 HEAT DISSIPATION
If the heat dissipation vent behind this unit is blocked, cooling
efficiency may deteriorate and temperature inside the unit will
rise. The temperature sensor that protects the unit will be
activated when internal temperature exceeds the pre-determined
level and power will be turned off automatically.Therefore,
please make sure pay attention not to block the heat dissipation
vent as well as the ventilation outlet behind the unit and ensure
that there is room for ventilation around it.
1.2.2 INSTALLATION REQUIREMENTS
Ensure that the minimal distance is maintained, as specified
below, between the unit with and the surrounding walls, as well
as the floor etc.Install the unit on stable flooring or stands.Take
precautionary measures to prevent the unit from tipping in order
to protect against accidents and earthquakes.
1.2.3 INSTALLATION REQUIREMENTS
To ensure safety in an emergency such as an earthquake, and
to prevent accidents, ensure that measures are taken to prevent
the TV dropping or falling over.
1.2.4 NOTES ON HANDLING
(1) WHEN TAKING UNIT OUT OF A PACKING CASE
When taking the unit out of a packing case, do not grasp
the upper part of the unit. If you take the unit out while
grasping the upper part, the LCD PANEL may be damaged
because of a pressure. Instead of grasping the upper part,
put your hands on the lower backside or sides of the unit.
(2) AS FOR PRESSING OR TOUCHING A SPEAKER
Be careful not to press the opening of the speaker in the
lower part of the unit and around them since the decorative
sheet on the surface of the openings may be deformed.
Ventilation hole
Ventilation hole
*Diagram differs from actual appearance.
*Diagram differs from actual appearance.
150 mm
200 mm
150 mm
200 mm
50 mm
MENU
INPUT +CHANNEL Ð + VOLUME Ð POWER
OPERATE
It fixes in a band.
TV Stand
*Diagram differs from actual appearance.

(No.YA333)1-5
1.3 HANDLING LCD PANEL
1.3.1 PRECAUTIONS FOR TRANSPORTATION
When transporting the unit, pressure exerted on the internal LCD
panel due to improper handling (such as tossing and dropping)
may cause damages even when the unit is carefully packed. To
prevent accidents from occurring during transportation, pay
careful attention before delivery, such as through explaining the
handling instructions to transporters.
Ensure that the following requirements are met during
transportation, as the LCD panel of this unit is made of glass and
therefore fragile:
(1) USE A SPECIAL PACKING CASE FOR THE LCD PANEL
When transporting the LCD panel of the unit, use a special
packing case (packing materials). A special packing case
is used when a LCD panel is supplied as a service spare
part.
(2) ATTACH PROTECTION SHEET TO THE FRONT
Since the front (display part) of the panel is vulnerable,
attach the protection sheet to the front of the LCD panel
before transportation. Protection sheet is used when a LCD
panel is supplied as a service spare part.
(3) AVOID VIBRATIONS AND IMPACTS
The unit may be broken if it is toppled sideways even when
properly packed. Continuous vibration may shift the gap of
the panel, and the unit may not be able to display images
properly. Ensure that the unit is carried by at least 2
persons and pay careful attention not to exert any vibration
or impact on it.
(4) DO NOT PLACE EQUIPMENT HORIZONTALLY
Ensure that it is placed upright and not horizontally during
transportation and storage as the LCD panel is very
vulnerable to lateral impacts and may break. During
transportation, ensure that the unit is loaded along the
traveling direction of the vehicle, and avoid stacking them
on one another. For storage, ensure that they are stacked
in 2 layers or less even when placed upright.
1.3.2 OPTICAL FILTER (ON THE FRONT OF THE LCD PANEL)
(1) Avoid placing the unit under direct sunlight over a
prolonged period of time. This may cause the optical filter
to deteriorate in quality and COLOUR.
(2) Clean the filter surface by wiping it softly and lightly with a
soft and lightly fuzz cloth (such as outing flannel).
(3) Do not use solvents such as benzene or thinner to wipe the
filter surface. This may cause the filter to deteriorate in
quality or the coating on the surface to come off. When
cleaning the filter, usually use the neutral detergent diluted
with water. When cleaning the dirty filter, use water-diluted
ethanol.
(4) Since the filter surface is fragile, do not scratch or hit it with
hard materials. Be careful enough not to touch the front
surface, especially when taking the unit out of the packing
case or during transportation.
1.3.3 PRECAUTIONS FOR REPLACEMENT OF EXTERIOR
PARTS
Take note of the following when replacing exterior parts (REAR
COVER, FRONT PANEL, etc.):
(1) Do not exert pressure on the front of the LCD panel (filter
surface). It may cause irregular COLOUR.
(2) Pay careful attention not to scratch or stain the front of the
LCD panel (filter surface) with hands.
(3) When replacing exterior parts, the front (LCD panel) should
be placed facing downward. Place a mat, etc. underneath
to avoid causing scratches to the front (filter surface).

1-6 (No.YA333)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
ASPECT
This feature will help you adjust the picture you are watching
to give you the best possible picture quality.
NATURAL CINEMA
Watching the movie or animation, press the Natural Cinema to
adjust the out line of the images to make thin more sharp.
VIDEO STATUS
Expression of a favorite screen can be chosen by the VIDEO
STATUS function.
MTS STEREO
The voice multiplex function of the MTS system is built in.
(MTS = Multi channel Television Sound system)
HYPER SURROUND
Creates a deep, three-dimensional sound effect by channeling
the audio through the TV's front-firing speakers.
2.2 MAIN DIFFERENCE LIST
2.3 TECHNICAL INFORMATION
2.3.1 LCD PANEL
This unit uses the flat type panel LCD (Liquid Crystal Display) panel that occupies as little space as possible, instead of the
conventional CRT (Cathode Ray Tube), as a display unit.
Since the unit has the two polarizing filter that are at right angles to each other, the unit adopts "normally black" mode, where light
does not pass through the polarizing filter and the screen is black when no voltage is applied to the liquid crystals.
2.3.1.1 SPECIFICATIONS
The following table shows the specifications of this unit.
Item LT-26X506/S LT-32X506/S
LCD PANEL UNIT QLD0370-001 QLD0371-001
DIGITAL PWB QAL0754-001 QAL0755-001
POWER PWB QAL0756-001 QAL0757-001
Item Specifications
LT-26X506 LT-32X506
Maximum dimensions ( W ×H ×D ) 626.0 mm ×373.0 mm ×51.0 mm 760.0 mm ×450.0 mm ×50.0 mm
Weight 4.7 kg 7.5 kg
Effective screen size Diagonal: 650 mm (H: 576 mm ×V: 324 mm) Diagonal: 800 mm (H: 697 mm ×V: 392 mm)
Aspect ratio 16 : 9
Drive device / system a-Si-TFT active matrix system
Resolution Horizontally 1366 ×Vertically 768 ×RGB < W-XGA > 3147264 dots in total
Pixel pitch (pixel size) Horizontally: 0.4215 mm Vertically: 0.4215mm
Horizontally: 0.51075 mm Vertically: 0.51075 mm
Displayed colour 16777216 colours 256 colours for R G and B
Brightness 500cd/m2
Contrast ratio 800 : 1 1000 : 1
Response time 8ms
View angle Horizontally: 170°Vertically: 170°
Surface polarizer Anti-Glare type Low reflective coat
Colour filter Vertical stripe
Backlight U-type Cold cathode fluorescent lamp ×8
Direct-type Cold cathode fluorescent lamp × 16
Power supply voltage in LCD 6.5 V
Power supply voltage in inverter 26.4 V 25.2 V
Panel interface system LVDS (Low Voltage Differential Signaling)

(No.YA333)1-7
2.3.1.2 PIXEL FAULT
There are three pixel faults - bright fault , dark fault and flicker fault - that are respectively defined as follows.
BRIGHT FAULT
In this pixel fault, a cell that should not light originally is lighting on and off.
For checking this pixel fault, input ALL BLACK SCREEN and find out the cell that is lighting on and off.
DARK FAULT
In this pixel fault, a cell that should light originally is not lighting or lighting with the brightness twice as brighter as originally lighting.
For checking this pixel fault, input 100% of each R/G/B colour and find out the cell that is not lighting.
FLICKER FAULT
In the pixel fault, a cell that should light originally or not light originally is flashing on and off.
For checking this pixel fault, input ALL BLACK SCREEN signal or 100% of each RGB colour and find out the cell that is flashing on
and off.
2.3.2 MAIN CPU PIN FUNCTION [U302 : MAIN PWB]
Pin Pin name I/O Function Pin Pin name I/O Function
1 HP-VOL O Headphone Volume control (pwm) 24 NC - Not Use
2
PWR-LED-B O POWER INDICATER CONTROL "HIGH" 25 IIC DATA I/O I2C bus Data(for inter IC)
3 PWR-LED-D O POWER INDICATER CONTROL "LOW" 26 IIC CLOCK I/O I2C bus Clock(for inter IC)
4 VSS - GND 27 PGEN O 6WIRE bus Enable(for MTL013)
5XIN I 32.768KHz for system clock (deviding to10MHz) 28 PGCLK O 6WIRE bus Clock(for MTL013)
6XOUT O 32.768KHz for system clock (deviding to10MHz) 29 THERMAL I heat watch
7VDD I5V 30 LVDS-PWR -NotUse
8 NC - Not Use 31 SYNC-IN I Horizontal sync(for sync detect)
9 TV-PWR O Main Power Control 32 RMT-IN I Remote control
10 AFT I Auto Fine Tuning Voltage input 33 NC - Not Use
11 KEY1 I key scan data 1 34 DATA1 I Enable for on boad flash CPU writer
12 KEY2 I key scan data 2 35 S1-TIN1 I video1 s1 terminal input detect
13 RESET I RESET 36 S1-TIN2 I video2 s1 terminal input detect
14 FILTER O Cllosed Caption-filter 37 D-TIN I video1 component terminal input detect
15 CVIN I CVBS for Cllosed Caption data slice 38 PG0 I/O 6WIRE bus data0(for MTL013)
16 NC - Not Use 39 PG1 I/O 6WIRE bus data1(for MTL013)
17 VS I Vertical sync 40 PG2 I/O 6WIRE bus data2(for MTL013)
18 HD I Horizontal sync 41 PG3 I/O 6WIRE bus data3(for MTL013)
19 R O R for closed caption 42 NC - Not Use
20 G O G for closed caption 43 HP-DET O Headphone terminal input detect
21 B O B for closed caption 44 CCFL O LAMP power control
22 BL O BLANKING for closed caption 45 PNL-PWR O LCD panel power control
23 AV-RST O Reset for inter IC 46 D-DIMMER O Pwm dimming control1(for LAMP)
24 NC - Not Use 47 A-DIMMER O Pwm dimming control2(for LAMP)
25 IIC DATA I/O I2C bus Data(for inter IC) 48 NC - Not Use

1-8 (No.YA333)
SECTION 3
DISASSEMBLY
3.1 DISASSEMBLY PROCEDURE
CAUTION AT DISASSEMBLY:
• Make sure that the power cord is disconnected from the outlet.
• Pay special attention not to break or damage the parts.
• When removing each board, remove the connectors as required. Taking notes of the connecting points (connector numbers)
makes service procedure manageable.
• Make sure that there is no bent or stain on the connectors before inserting, and firmly insert the connectors.
3.1.1 REMOVING THE STAND
(1) Remove the JACK COVER.
(2) Remove the 2 screws [A], then remove the STAND
COVER.
(3) Remove the 4 screws [B], then remove the STAND.
3.1.2 REMOVING THE REAR COVER
• Remove the STAND.
(1) Remove the 8 screws [C], 1 screw [D] and 2 screws [E],
then remove the REAR COVER.
3.1.3 REMOVING THE POWER PWB
• Remove the STAND.
• Remove the REAR COVER.
(1) Remove the 3 screws [F] and 1 screw [G], then remove the
TERMINAL BASE.
(2) Remove the 8 screws [H], then remove the BACK
BRACKET.
(3) Remove the 6 screws [J], then remove the POWER PWB
SHIELD.
(4) Remove the 5 screws [K], then remove the POWER PWB.
3.1.4 REMOVING THE MAIN PWB
• Remove the STAND.
• Remove the REAR COVER.
• Remove the TERMINAL BASE.
• Remove the BACK BRACKET.
• Remove the POWER PWB SHIELD.
(1) Remove the 6 screws [L], then remove the MAIN PWB.
3.1.5 REMOVING THE DIGITAL PWB
• Remove the STAND.
• Remove the REAR COVER.
• Remove the TERMINAL BASE.
• Remove the BACK BRACKET.
(1) Remove the 4 screws [M], then remove the DIGITAL PWB.
3.1.6 REMOVING THE KEY PWB
• Remove the STAND.
• Remove the REAR COVER.
(1) Remove the 2 screws [P], then remove the KEY PWB.
3.1.7 REMOVING THE LED PWB
• Remove the STAND.
• Remove the REAR COVER.
(1) Remove the 2 screws [Q], then remove the LED PWB.
3.1.8 REMOVING THE SPEAKER
• Remove the STAND.
• Remove the REAR COVER.
(1) Remove the 6 screws [R], then remove the SPEAKER (L/
R).
CAUTION:
Please do not disassembly the SPEAKER.
When the speaker is decomposed, the performance cannot be
kept.
3.1.9 REMOVING THE LCD PANEL UNIT
• Remove the STAND.
• Remove the REAR COVER.
• Remove the TERMINAL BASE.
• Remove the BACK BRACKET.
(1) Remove the 6 screws [S], then remove the MAIN BASE.
(2) Remove the 6 screws [T], then remove the FRONT
PANEL.
(3) Remove the 2 screws [U], then remove the TOP FRAME.
(4) Remove the 2 screws [V], then remove the BOTTOM
FRAME.
NOTE:
• Pay special attention not to break or damage on the FRONT
PANEL.
• The LCD PANEL UNIT is fixed to the FRONT PAMEL (at the
back side)by using double-side adhesive tapes. To remove
the LCD PANEL UNIT, remove the adhesive tape on the
FRONT PANEL slowly.

(No.YA333)1-9
Fig.1
BACK BRACKET
POWER PWB SHIELD
MAIN BASE
INSULATOR
TOP FRAME
BOTTOM FRAME
STAND
STAND COVER
JACK COVER
REAR COVER
POWER PWB
POWER CORD
LCD PANEL UNIT
KEY PWB
KNOB BASE
LED PWB
FRONT PANEL
TERMINAL BASE
SPEAKER
SPEAKER
MAIN PWB
DIGITAL PWB
A
B
C
D
H
H
M
F
L
L
G
R
S
R
P
V
T
U
U
T
K
S
J
E
Q
CONTROL KNOB
This exploded view shows the LT-26X506.
LT-32X506 slightly differs from this exploded
view, however it can be disassembled in the
same procedure as LT-26X506.

1-10 (No.YA333)
3.2 MEMORY IC REPLACEMENT
• This model uses the memory IC.
• This memory IC stores data for proper operation of the video and drive circuits.
• When replacing, be sure to use an IC containing this (initial value) data.
3.2.1 MEMORY IC REPLACEMENT PROCEDURE
1. Power off
Switch off the power and disconnect the power plug from the AC outlet.
2. Replace the memory IC
Be sure to use the memory IC written with the initial setting values.
3. Power on
Connect the power plug to the AC outlet and switch on the power.
4. Receiving channel setting
Refer to the OPERATING INSTRUCTIONS and set the receive channels (Channels Preset) as described.
5. User setting
Check the user setting items according to the given in page later. Where these do not agree, refer to the OPERATING
INSTRUCTIONS and set the items as described.
6. SERVICE MODE setting
Verify what to set in the SERVICE MODE, and set whatever is necessary (Fig.1). Refer to the SERVICE ADJUSTMENT for setting.
3.2.2 SERVICE MODE SETTING
SERVICE MODE SCREEN
Fig.1
NOTE:
As self check feature is not used in this TV, “2. SELF
CHECK” cannot be selected (screen display only).
SETTING ITEM
SERVICE MENU
SERVICE MENU
1.ADJUST
1.ADJUST
2.SELF_CHECK
2.SELF_CHECK
3.I2C STOP
3.I2C STOP
SERVICE MODE SCREEN
ADJUSTMENT MODE SCREEN
S001 R DRIVE 126
S001 R DRIVE 126
NT FULL STD H
NT FULL STD H
Not used
(Display only)
Setting items Settings Item No.
Video system setting Adjust S001 - S024

(No.YA333)1-11
3.2.3 SETTINGS OF FACTORY SHIPMENT
3.2.3.1 BUTTON OPERATION 3.2.3.2 REMOTE CONTROL DIRECT OPERATION
3.2.3.3 REMOTE CONTROL MENU OPERATION
1. PICTURE ADJUST
Customers can adjust the picture setting of menu screen as their
own like but the picture standard value during factory shipment is as
below.
< NTSC MODE >
< HD MODE >
2. SOUND ADJUST
3. CLOCK / TIMERS
4. INITIAL SETUP
Setting item Setting position
POWER Off
CHANNEL CABLE-02
VOLUME 10
Setting item Setting position
INPUT TV
CHANNEL CABLE-02
VOLUME 10
DISPLAY OFF
ASPECT NTSC PANORAMA
HD / ATSC FULL
SLEEP TIMER OFF
VIDEO STATUS DYNAMIC
HYPER SURROUND OFF
Setting item DYNAMIC STANDARD GAME THEATER
PICTURE 00 00 00 00
BRIGHT 00 00 00 00
COLOR [phone]
TINT 00 00 00 00
DETAIL +05 00 00 00
ENERGY SAVER MODE +30 +20 00 -10
COLOR TEMPERATURE HIGH LOW HIGH HIGH
DIG. NOISE CLEAR OFF OFF OFF OFF
NATURAL CINEMA AUTO AUTO AUTO AUTO
Setting item
DYNAMIC STANDARD GAME THEATER
PICTURE 00 00 00 00
BRIGHT 00 00 00 00
COLOR +05 00 -10 00
TINT 00 00 00 00
DETAIL +05 00 00 00
ENERGY SAVER MODE +30 +20 00 -10
COLOR TEMPERATURE HIGH LOW HIGH LOW
DIG. NOISE CLEAR OFF OFF OFF OFF
NATURAL CINEMA AUTO AUTO AUTO AUTO
Setting item Setting position
BASS 00
TREBLE 00
BALANCE 00
Setting item Setting position
ON / OFF TIMER OFF
Setting item Setting position
NOISE MUTING ON
FRONT PANEL LOCK OFF
POWER INDICATOR HIGH
LANGUAGE ENG.
CLOSED CAPTION OFF(CC1/T1)
AUTO SHUT OFF OFF
XDS ID ON
V-CHIP OFF

1-12 (No.YA333)
3.3 REPLACEMENT OF CHIP COMPONENT
3.3.1 CAUTIONS
(1) Avoid heating for more than 3 seconds.
(2) Do not rub the electrodes and the resist parts of the pattern.
(3) When removing a chip part, melt the solder adequately.
(4) Do not reuse a chip part after removing it.
3.3.2 SOLDERING IRON
(1) Use a high insulation soldering iron with a thin pointed end of it.
(2) A 30w soldering iron is recommended for easily removing parts.
3.3.3 REPLACEMENT STEPS
1. How to remove Chip parts
[Resistors, capacitors, etc.]
(1) As shown in the figure, push the part with tweezers and
alternately melt the solder at each end.
(2) Shift with the tweezers and remove the chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply extra solder to each lead.
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove
the chip part.
NOTE :
After removing the part, remove remaining solder from the
pattern.
2. How to install Chip parts
[Resistors, capacitors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the
solder. Then heat and melt the solder at both ends of the
chip part.
[Transistors, diodes, variable resistors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(2) Grasp the chip part with tweezers and place it on the
solder.
(3) First solder lead Aas indicated in the figure.
(4) Then solder leads Band C.
SOLDER SOLDER
AB
C
A
B
C

(No.YA333)1-13
SECTION 4
ADJUSTMENT
4.1 ADJUSTMENT PREPARATION
(1) There are 2 ways of adjusting this TV : One is with the
REMOTE CONTROL UNIT and the other is the
conventional method using adjustment parts and
components.
(2) The adjustment using the REMOTE CONTROL UNIT is
made on the basis of the initial setting values. The
setting values which adjust the screen to the optimum
condition can be different from the initial setting
values.
(3) Make sure that connection is correctly made AC to AC
power source.
(4) Turn on the power of the TV and measuring instruments for
warming up for at least 30 minutes before starting
adjustments.
(5) If the receive or input signal is not specified, use the most
appropriate signal for adjustment.
(6) Never touch the parts (such as variable resistors,
transformers and condensers) not shown in the adjustment
items of this service adjustment.
4.2 PRESET SETTING BEFORE ADJUSTMENTS
Unless otherwise specified in the adjustment items, preset the
following functions with the REMOTE CONTROL UNIT.
4.3 MEASURING INSTRUMENT AND FIXTURES
• Signal generator (Pattern generator)[NTSC]
• Remote control unit
4.4 ADJUSTMENT ITEMS
VIDEO CIRCUIT
• WHITE BALANCE (HIGH LIGHT) adjustment
4.5 BASIC OPERATION OF SERVICE MODE
4.5.1 HOW TO ENTER THE SERVICE MODE
(1) Set to 0 minutes using the [SLEEP TIMER] key.
(2) Press the [VIDEO STATUS] key and [DISPLAY] key
simultaneosly, then enter the SERVICE MODE.
NOTE:
• As self check feature is not used in this TV, “2. SELF
CHECK” cannot be selected (screen display only).
• Before entering the SERVICE MODE, confirm that the
setting of TV/CATV switch of the REMOTE CONTROL UNIT
is at the "TV" side and the setting of VCR/DVD switch is at
the "VCR" side. If the switches have not been properly set,
you cannot enter the SERVICE MODE.
• When a number key other than the [1] keys is pressed in the
SERVICE MENU SCREEN, the other relevant screen may
be displayed.
This is not used in the adjustment procedure. Press the
[MENU] key to return to the SERVICE MENU SCREEN.
4.5.2 HOW TO EXIT THE SERVICE MODE
Press the [BACK] key to exit the Service mode.
Setting item Settings position
PICTURE MODE STANDARD
PICTURE adjustments Centre
COLOUR TEMP. NORMAL
SOUND adjustments Centre
SERVICE MENU
SERVICE MENU
1.ADJUST
1.ADJUST
2.SELF_CHECK
2.SELF_CHECK
3.I2C STOP
3.I2C STOP
SERVICE MODE SCREEN
ADJUSTMENT MODE SCREEN
S001 R DRIVE 126
S001 R DRIVE 126
NT FULL STD H
NT FULL STD H
Not used
(Display only)

1-14 (No.YA333)
4.5.3 DESCRIPTION OF STATUS DISPLAY OF
ADJUSTMENT MODE
(1) SIGNAL SYSTEM
The signal displayed on the screen is displayed.
(2) SCREEN MODE
(3) VIDEO STATUS
(4) COLOR TEMPERATURE
(5) SETTING ITEM NAME
Setting item name are displayed. The setting item numbers to
be displayed are listed below.
(6) SETTING ITEM NO.
Setting item numbers are displayed. For the setting item
names to be displayed, refer to "Initial setting value of adjust-
ment mode".
(7) SETTING VALUE (DATA)
The SETTING VALUE is displayed.
4.5.4 CHANGE AND MEMORY OF SETTING VALUE
SELECTION OF SETTING ITEM
• [CH+] / [CH-] key.
Change the setting items up/ down.
CHANGE OF SETTING VALUE (DATA)
• [VOL+] / [VOL-] key.
Change the setting values up/down.
MEMORY OF SETTING VALUE (DATA)
Changed setting value is memorized by pressing [MUTING]
key.
4.5.5 SERVICE MODE SELECT KEY LOCATION
NT : 525i (Composite / S-video input)
5I : 525i (Component input)
5P : 525p
1I : 1125i
7P : 750p
FULL : FULL
1609 : CINEMA, CINEMA ZOOM
PANO : PANORAMA, HD PANORAMA
REGU : REGULAR
STD : STANDARD
DYN : DYNAMIC
TH : THEATER
GAME : GAME
H:HIGH
L:LOW
Item No. Setting item
S001 - S024 Video system setting
S001 R DRIVE 126
S001 R DRIVE 126
NT FULL STD H
NT FULL STD H
SIGNAL SYSTEM SCREEN MODE PICTURE MODE
SETTING VALUE (DATA)SETTINGITEM No. SETTING ITEM
COLOUR TEMP.
POWER
VCR/DVD switch
NUMBER
DISPLAY
VOL-
TV/CATV switch
MENU
SLEEP TIMER
VIDEO STATUS ASPECT CH+
VOL+
CH-
EXIT
RM-C1271G

(No.YA333)1-15
4.6 INITIAL SETTING VALUES IN THE SERVICE MODE
• Perform fine-tuning based on the "initial values" using the remote control when in the Service mode.
• The "initial values" serve only as an indication rough standard and therefore the values with which optimal display can be achieved
may be different from the default values. But, don't change the values that are not written in "ADJUSTMENT PROCEDURE". They
are fixed values.
4.6.1 VIDEO SYSTEM SETTING
Item
No. Item name Variable range Setting value Remark
LT-26X506 LT-32X506
S001 R DRIVE 0 - 255 128 125 Initial setting value is reference value at following condition.
INPUT SIGNAL: NTSC MODE (SD MODE)
COLOR TEMPERATURE: LOW
VIDEO STATUS: STANDARD
S002 G DRIVE 0 - 255 128 125
S003 B DRIVE 0 - 255 128 125
S004 R ST LO HD -63 - 63 0 0 Initial setting value is reference value at following condition.
INPUT SIGNAL: HD MODE
COLOR TEMPERATURE: LOW
VIDEO STATUS: STANDARD
S005 G ST LO HD -63 - 63 0 0
S006 B ST LO HD -63 - 63 0 0
S007 R ST HI SD -63 - 63 -6 -6 Initial setting value is reference value at following condition.
INPUT SIGNAL: NTSC MODE (SD MODE)
COLOR TEMPERATURE: HIGH
VIDEO STATUS: STANDARD
S008 G ST HI SD -63 - 63 -6 -6
S009 B ST HI SD -63 - 63 0 0
S010 R ST HI HD -63 - 63 -6 -6 Initial setting value is reference value at following condition.
INPUT SIGNAL: HD MODE
COLOR TEMPERATURE: HIGH
VIDEO STATUS: STANDARD
S011 G ST HI HD -63 - 63 -9 -9
S012 B ST HI HD -63 - 63 0 0
S013 R TH LO SD -63 - 63 0 0 Initial setting value is reference value at following condition.
INPUT SIGNAL: NTSC MODE (SD MODE)
COLOR TEMPERATURE: LOW
VIDEO STATUS: THEATER
S014 G TH LO SD -63 - 63 -9 -9
S015 B TH LO SD -63 - 63 -24 -24
S016 R TH LO HD -63 - 63 0 0 Initial setting value is reference value at following condition.
INPUT SIGNAL: HD MODE
COLOR TEMPERATURE: LOW
VIDEO STATUS: THEATER
S017 G TH LO HD -63 - 63 -9 -9
S018 B TH LO HD -63 - 63 -24 -24
S019 R TH HI SD -63 - 63 0 0 Initial setting value is reference value at following condition.
INPUT SIGNAL: NTSC MODE (SD MODE)
COLOR TEMPERATURE: HIGH
VIDEO STATUS: THEATER
S020 G TH HI SD -63 - 63 -1 -1
S021 B TH HI SD -63 - 63 -15 -15
S022 R TH HI HD -63 - 63 0 0 Initial setting value is reference value at following condition.
INPUT SIGNAL: HD MODE
COLOR TEMPERATURE: HIGH
VIDEO STATUS: THEATER
S023 G TH HI HD -63 - 63 -1 -1
S024 B TH HI HD -63 - 63 -15 -15

1-16 (No.YA333)
4.7 ADJUSTMENT PROCEDURE
4.7.1 VIDEO CIRCUIT
SECTION 5
TROUBLESHOOTING
This service manual does not describe TROUBLESHOOTING.
Item Measuring
instrument Test point Adjustment part Description
WHITE
BALANCE
(HIGHLIGHT)
Remote
control unit
Signal
generator
[1.ADJUST]
S001: R DRIVE (Red drive)
S002: G DRIVE (Green drive)
S003: B DRIVE (Blue drive)
(1) Receive a NTSC 75% all white signal.
(2) Set "VIDEO STATUS" to "STANDARD".
(3) Set "ASPECT" to "FULL".
(4) Select "COLOUR TEMPERATURE" to "LOW".
(5) Select "1.ADJUST" from the SERVICE MODE.
(6) Set < S001 > (R DRIVE), < S002 > (G DRIVE)
and < S003 > (B DRIVE) to "133".
(7) Adjust to keep one of < S001 > (Red drive),
< S002 > (Green drive) or < S003 > (Blue drive)
unchanged, then lower the other two so that the
all-white screen is equally white throughout.
NOTE:
Set one or more of < S001 >, < S002 >, and
< S003 > to "128" [LT-26X506] or "125" [LT-
32X506].
(8) Check that white balance is properly tracked
from low light to high light. If the white balance
tracking is deviated, adjust to correct it.
(9) Press the [MUTING] key to memoirze the set
value.

(No.YA333)
AV & MULTIMEDIA COMPANY DISPLAY CATEGORY 12, 3-chome, Moriya-cho, Kanagawa-ku, Yokohama-city, Kanagawa-prefecture, 221-8528, Japan
Victor Company of Japan, Limited
VPT
Printed in Japan

COPYRIGHT © 2005 Victor Company of Japan, Limited No.YA333
2005/10
LCD FLAT TELEVISION
YA33320058LT-26X506/S,
LT-32X506/S
BASIC CHASSIS
FU
SCHEMATIC DIAGRAMS
CD-ROM No.SML200510

2-1(No.YA333)
5.NOTE FOR REPAIRING SERVICE
This model's power circuit is partly different in the GND. The
difference of the GND is shown by the LIVE : ( ) side GND and the
ISOLATED(NEUTRAL): ( ) side GND. Therefore, care must be
taken for the following points.
(1)Do not touch the LIVE side GND or the LIVE side GND and the
ISOLATED(NEUTRAL)side GND simultaneously. if the above
caution is not respected, an electric shock may be caused.
Therefore, make sure that the power cord is surely removed from
the receptacle when, for example, the chassis is pulled out.
(2)Do not short between the LIVE side GND and ISOLATED(NEUTRAL)
side GND or never measure with a measuring apparatus measure
with a measuring apparatus ( oscilloscope, etc.) the LIVE side GND
and ISOLATED(NEUTRAL)side GND at the same time.
If the above precaution is not respected, a fuse or any parts will be broken.
Since the circuit diagram is a standard one, the circuit and
circuit constants may be subject to change for improvement
without any notice.
NOTE
Due improvement in performance, some part numbers show
in the circuit diagram may not agree with those indicated in
the part list.
When ordering parts, please use the numbers that appear
in the Parts List.
STANDARD CIRCUIT DIAGRAM
NOTE ON USING CIRCUIT DIAGRAMS
(7)Ground symbol
: LIVE side ground
: ISOLATED(NEUTRAL)side ground
: EARTH ground
: DIGITAL ground
(6)Connecting method
: Connector : Wrapping or soldering
: Receptacle
(5)Test point
:Test point : Only test point display
Respective voltage values are indicated
: B1
: 9V : 5V
: B2 (12V)
(4)Power Supply
Type
MM : Metalizedmylarcapacitor
PP : Polypropylene capacitor
MPP : Metalized polypropylene capacitor
MF : Metalized film capacitor
TF : Thin film capacitor
BP :Bipolar electrolytic capacitor
TAN : Tantalum capacitor
(3)Coils
No unit
Others : [µH]
: As specified
No indication : Ceramic capacitor
(2)Capacitors
Capacitance value
1or higher : [pF]
less than 1 : [µF]
Withstand voltage
No indication : DC50[V]
Others : DC withstand voltage [V]
AC indicated : AC withstand voltage [V]
Electrolytic Capacitors
47/50[Example]: Capacitance value [µF]/withstand voltage[V]
Composition resistor 1/2 [W] is specified as 1/2S or Comp.
Type
No indication : Carbon resistor
OMR : Oxide metal film resistor
MFR : Metal film resistor
MPR : Metal plate resistor
UNFR : Uninflammable resistor
FR : Fusible resistor
4.INDICATIONS ON THE CIRCUIT DIAGRAM
(1)Resistors
Resistance value
No unit : [Ω]
K: [kΩ]
M
Rated allowable power
No indication : 1/16 [W]
Others : As specified
: [MΩ]
3.INDICATION OF PARTS SYMBOL [EXAMPLE]
In the PW board : R209 R209
1.SAFETY
The components identified by the symbol and shading are
critical for safety. For continued safety replace safety ciritical
components only with manufactures recommended parts.
Since the voltage values of signal circuit vary to some extent
according to adjustments, use them as reference values.
2.SPECIFIED VOLTAGE AND WAVEFORM VALUES
The voltage and waveform values have been measured under the
following conditions.
(1)Input signal : Colour bar signal
(2)Setting positions of
each knob/button and
variable resistor
(3)Internal resistance of tester : DC 20kΩ/V
(4)Oscilloscope sweeping time : H 20µs / div
: V 5ms / div
: Othters Sweeping time is
specified
(5)Voltage values : All DC voltage values
: Original setting position
when shipped
LT-26X506/S, LT-32X506/S

SEMICONDUCTOR SHAPES
CONTENTS
SEMICONDUCTOR SHAPES ......................................................................2-2
WIRING DIAGRAM........................................................................................2-3
BLOCK DIAGRAM........................................................................................2-5
CIRCUIT DIAGRAMS
MAIN PWB CIRCUIT DIAGRAM ................................................................................................................ 2-7
DIGITAL SIGNAL PWB CIRCUIT DIAGRAM ........................................................................................... 2-17
POWER PWB CIRCUIT DIAGRAM [LT-26X506/S] ................................................................................... 2-25
POWER PWB CIRCUIT DIAGRAM [LT-32X506/S] ................................................................................... 2-31
LED BOARD PWB CIRCUIT DIAGRAM ................................................................................................... 2-37
KEY PWB CIRCUIT DIAGRAM................................................................................................................. 2-38
PATTERN DIAGRAMS
MAIN PWB PWB PATTERN ..................................................................................................................... 2-39
DIGITAL SIGNAL PWB PATTERN ........................................................................................................... 2-43
POWER PWB PATTERN [LT-26X506/S]................................................................................................... 2-47
POWER PWB PATTERN [LT-32X506/S]................................................................................................... 2-51
LED BOARD PWB PATTERN ................................................................................................................... 2-55
KEY PWB PATTERN ................................................................................................................................ 2-55
VOLTAGE CHATRS................................................................................... 2-56
WAVEFORMS ............................................................................................ 2-57
USING P.W. BOARD
P.W.B ASS’Y name
MAINP.W.BOARD
DIGITALSIGNAL P.W BOARD
POWER P.W. BOARD
LED P.W. BOARD
KEYP.W. BOARD
QAL0753-001
QAL0754-001
QAL0756-001
QAL0758-001
QAL0759-001
LT-26X506/S LT-32X506/S
QAL0755-001
QAL0757-001
(No.YA333)2-2
IC BOTTOM VIEW FRONT VIEW TOP VIEW
1 N
N
1
OUT
E
IN IN OUTE
1 N
TOPVIEW
1
N
1
N
CHIP IC
TRANSISTOR
BOTTOMVIEW FRONT VIEW TOPVIEW
CHIP TR
E
C
BECB
C
BE
B
(G)
E
(S)
C
(D)
ECB
ECB