Text preview for : jvc_lt-26a61bj_lt-32a61bu_chassis_ft_sm_[ET].pdf part of JVC LT-26a61bj_LT-32a61bu Service manual JVC LT-26a61bj--LT-32a61bu
Back to : LT-26a61bj_LT-32a61bu_ch. | Home
SERVICE MANUAL
WIDE LCD PANEL TELEVISION
12
2005
YA369
LT-26A61BJ, LT-26A61BU, LT-26A61BU/C,
LT-26A61SJ, LT-26A61SU, LT-26A61SU/C,
LT-32A61BJ, LT-32A61BU, LT-32A61BU/C,
LT-32A61SJ, LT-32A61SU, LT-32A61SU/C
BASIC CHASSIS
FT
TABLE OF CONTENTS
1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
COPYRIGHT © 2005 Victor Company of Japan, Limited No.YA369
2005/12
SPECIFICATION
Contents
LT-26A61BJ LT-32A61BJ
Items LT-26A61BU LT-32A61BU
LT-26A61SJ LT-32A61SJ
LT-26A61SU LT-32A61SU
Dimensions ( W × H × D ) 68.6 cm × 52.5 cm × 26.9 cm [Included stand] 82.0 cm × 60.2 cm × 26.9 cm [Included stand]
68.6 cm × 47.4 cm × 12.1 cm [TV only] 82.0 cm × 55.1 cm × 12.7 cm [TV only]
Mass 14.9 kg [Included stand] 18.8 kg [Included stand]
12.3 kg [TV only] 15.4 kg [TV only]
Power Input AC110V - AC240 V, 50 Hz / 60 Hz
Power Consumption 158 W (Standby: 2.1 W)
TV RF System CCIR (B/G, I, D/K, L)
Colour System PAL, SECAM, NTSC 3.58/4.43 [EXT only]
Stereo System NICAM (B/G, I, D/K, L), A2 (B/G, D/K)
Teletext System FLOF (Fastext level 2.5), TOP, WST(World Standard system)
Receiving Frequency VHF: 47MHz - 470MHz
UHF: 470MHz - 862MHz
Intermediate VIF 38.9MHz (B/G, I, D/K, L)
Frequency SIF 33.4MHz (5.5MHz :B/G)
32.9MHz (6.0MHz :I)
32.4MHz (6.5MHz :D/K)
Colour Sub PAL 4.43MHz
Carrier SECAM 4.40625MHz / 4.25MHz
Frequency NTSC 3.58MHz / 4.43MHz
LCD panel 26V-inch wide aspect (16 : 9) 32V-inch wide aspect (16 : 9)
Screen Size Diagonal : 66 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 5W+5W
Speaker 6.6 cm, round type × 2 (Oblique corn)
Aerial terminal (VHF/UHF) 75 unbalanced, coaxial
EXT-1 / EXT-2 (Input / Output) 21-pin Euro connector (SCART socket ) × 2
EXT-3 (Input) S-Video Mini-DIN 4 pin × 1
Y: 1 V (p-p), Positive (Negative sync provided), 75
C: 0.286 V (p-p) (Burst signal), 75
Video 1 V (p-p), Positive (Negative sync provided), 75 , RCA pin jack × 1
Audio 500 mV (rms), High impedance, RCA pin jack × 2
EXT-4 (Input) Component Video RCA pin jack × 3
1125i/750p Y : 1 V (p-p) (Sync signal: ±0.35V(p-p), 3-value sync.), 75
Pb/Pr : ±0.35V(p-p), 75
625p / 525p / 625i / 525i Y : 1 V (p-p), Positive (Negative sync provided), 75
Cb/Cr : 0.7V(p-p), 75
DIGITAL Input DVI-D signal link 19pin connector × 1(Digital-input terminal is not compatible with computer signal)
Headphone 3.5 mm stereo mini jack × 1
Remote Control Unit RM-C1816S (AA/R6 dry cell battery × 2)
Design & specifications are subject to change without notice.
1-2 (No.YA369)
SECTION 1
PRECAUTION
1.1 SAFETY PRECAUTIONS [EXCEPT FOR UK]
(1) The design of this product contains special hardware, (6) Isolation Check (Safety for Electrical Shock Hazard)
many circuits and components specially for safety After re-assembling the product, always perform an
purposes. For continued protection, no changes should be isolation check on the exposed metal parts of the cabinet
made to the original design unless authorized in writing by (antenna terminals, video/audio input and output terminals,
the manufacturer. Replacement parts must be identical to Control knobs, metal cabinet, screw heads, earphone jack,
those used in the original circuits. Service should be control shafts, etc.) to be sure the product is safe to operate
performed by qualified personnel only. without danger of electrical shock.
(2) Alterations of the design or circuitry of the products should a) Dielectric Strength Test
not be made. Any design alterations or additions will void The isolation between the AC primary circuit and all metal
the manufacturer's warranty and will further relieve the parts exposed to the user, particularly any exposed metal
manufacturer of responsibility for personal injury or part having a return path to the chassis should withstand a
property damage resulting therefrom. voltage of 3000V AC (r.m.s.) for a period of one second. (.
(3) Many electrical and mechanical parts in the products have . . . Withstand a voltage of 1100V AC (r.m.s.) to an
special safety-related characteristics. These appliance rated up to 120V, and 3000V AC (r.m.s.) to an
characteristics are often not evident from visual inspection appliance rated 200V or more, for a period of one second.)
nor can the protection afforded by them necessarily be This method of test requires a test equipment not generally
obtained by using replacement components rated for found in the service trade.
higher voltage, wattage, etc. Replacement parts which b) Leakage Current Check
have these special safety characteristics are identified in Plug the AC line cord directly into the AC outlet (do not use
the parts list of Service manual. Electrical components a line isolation transformer during this check.). Using a
having such features are identified by shading on the "Leakage Current Tester", measure the leakage current
schematics and by ( ) on the parts list in Service from each exposed metal part of the cabinet, particularly
manual. The use of a substitute replacement which does any exposed metal part having a return path to the chassis,
not have the same safety characteristics as the to a known good earth ground (water pipe, etc.). Any
recommended replacement part shown in the parts list of leakage current must not exceed 0.5mA AC (r.m.s.).
Service manual may cause shock, fire, or other hazards. However, in tropical area, this must not exceed 0.2mA AC
(4) Don't short between the LIVE side ground and (r.m.s.).
ISOLATED (NEUTRAL) side ground or EARTH side Alternate Check Method
ground when repairing. Plug the AC line cord directly into the AC outlet (do not
Some model's power circuit is partly different in the GND. use a line isolation transformer during this check.). Use
The difference of the GND is shown by the LIVE : ( ) side an AC voltmeter having 1000 per volt or more
GND, the ISOLATED (NEUTRAL) : ( ) side GND and sensitivity in the following manner. Connect a 1500
EARTH : ( ) side GND. 10W resistor paralleled by a 0.15µF AC-type capacitor
Don't short between the LIVE side GND and ISOLATED between an exposed metal part and a known good earth
(NEUTRAL) side GND or EARTH side GND and never ground (water pipe, etc.). Measure the AC voltage
measure the LIVE side GND and ISOLATED (NEUTRAL) across the resistor with the AC voltmeter. Move the
side GND or EARTH side GND at the same time with a resistor connection to each exposed metal part,
measuring apparatus (oscilloscope etc.). If above note will particularly any exposed metal part having a return path
not be kept, a fuse or any parts will be broken. to the chassis, and measure the AC voltage across the
(5) When service is required, observe the original lead dress. resistor. Now, reverse the plug in the AC outlet and
Extra precaution should be given to assure correct lead repeat each measurement. Any voltage measured must
dress in the high voltage circuit area. Where a short circuit not exceed 0.75V AC (r.m.s.). This corresponds to
has occurred, those components that indicate evidence of 0.5mA AC (r.m.s.).
overheating should be replaced. Always use the However, in tropical area, this must not exceed 0.3V AC
manufacturer's replacement components. (r.m.s.). This corresponds to 0.2mA AC (r.m.s.).
AC VOLTMETER
(HAVING 1000 /V,
OR MORE SENSITIVITY)
0.15 F AC-TYPE
PLACE THIS PROBE
ON EACH EXPOSED
1500 10W METAL PART
GOOD EARTH GROUND
(No.YA369)1-3
1.2 SAFETY PRECAUTIONS [FOR UK]
(1) The design of this product contains special hardware and 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 product 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 product have special safety-related characteristics. These characteristics are often
not evident from visual inspection nor can the protection afforded by them necessary 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 the 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) The leads in the products are routed and dressed with ties, clamps, tubing's, barriers and the like to be separated from live parts,
high temperature parts, moving parts and / or sharp edges for the prevention of electric shock and fire hazard. When service is
required, the original lead routing and dress should be observed, and it should be confirmed that they have been returned to
normal, after re-assembling.
WARNING
(1) The equipment has been designed and manufactured to meet international safety standards.
(2) It is the legal responsibility of the repairer to ensure that these safety standards are maintained.
(3) Repairs must be made in accordance with the relevant safety standards.
(4) It is essential that safety critical components are replaced by approved parts.
(5) If mains voltage selector is provided, check setting for local voltage.
1-4 (No.YA369)
1.3 INSTALLATION
1.3.1 HEAT DISSIPATION 1.3.3 INSTALLATION REQUIREMENTS
If the heat dissipation vent behind this unit is blocked, cooling To ensure safety in an emergency such as an earthquake, and
efficiency may deteriorate and temperature inside the unit will to prevent accidents, ensure that measures are taken to prevent
rise. The temperature sensor that protects the unit will be the TV dropping or falling over.
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.
It fixes in a band.
Ventilation hole TV Stand
*Diagram differs from actual appearance.
Ventilation hole
1.3.4 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,
*Diagram differs from actual appearance.
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
1.3.2 INSTALLATION REQUIREMENTS lower part of the unit and around them since the decorative
Ensure that the minimal distance is maintained, as specified sheet on the surface of the openings may be deformed.
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.
200 mm 200 mm
150 mm 150 mm
50 mm
*Diagram differs from actual appearance.
(No.YA369)1-5
1.4 HANDLING LCD PANEL
1.4.1 PRECAUTIONS FOR TRANSPORTATION 1.4.2 OPTICAL FILTER (ON THE FRONT OF THE LCD PANEL)
When transporting the unit, pressure exerted on the internal LCD (1) Avoid placing the unit under direct sunlight over a
panel due to improper handling (such as tossing and dropping) prolonged period of time. This may cause the optical filter
may cause damages even when the unit is carefully packed. To to deteriorate in quality and COLOUR.
prevent accidents from occurring during transportation, pay (2) Clean the filter surface by wiping it softly and lightly with a
careful attention before delivery, such as through explaining the soft and lightly fuzz cloth (such as outing flannel).
handling instructions to transporters. (3) Do not use solvents such as benzene or thinner to wipe the
Ensure that the following requirements are met during filter surface. This may cause the filter to deteriorate in
transportation, as the LCD panel of this unit is made of glass and quality or the coating on the surface to come off. When
therefore fragile: cleaning the filter, usually use the neutral detergent diluted
(1) USE A SPECIAL PACKING CASE FOR THE LCD PANEL with water. When cleaning the dirty filter, use water-diluted
When transporting the LCD panel of the unit, use a special ethanol.
packing case (packing materials). A special packing case (4) Since the filter surface is fragile, do not scratch or hit it with
is used when a LCD panel is supplied as a service spare hard materials. Be careful enough not to touch the front
part. surface, especially when taking the unit out of the packing
(2) ATTACH PROTECTION SHEET TO THE FRONT case or during transportation.
Since the front (display part) of the panel is vulnerable,
attach the protection sheet to the front of the LCD panel 1.4.3 PRECAUTIONS FOR REPLACEMENT OF EXTERIOR
before transportation. Protection sheet is used when a LCD PARTS
panel is supplied as a service spare part. Take note of the following when replacing exterior parts (REAR
(3) AVOID VIBRATIONS AND IMPACTS COVER, FRONT PANEL, etc.):
The unit may be broken if it is toppled sideways even when (1) Do not exert pressure on the front of the LCD panel (filter
properly packed. Continuous vibration may shift the gap of surface). It may cause irregular COLOUR.
the panel, and the unit may not be able to display images (2) Pay careful attention not to scratch or stain the front of the
properly. Ensure that the unit is carried by at least 2 LCD panel (filter surface) with hands.
persons and pay careful attention not to exert any vibration (3) When replacing exterior parts, the front (LCD panel) should
or impact on it. be placed facing downward. Place a mat, etc. underneath
(4) DO NOT PLACE EQUIPMENT HORIZONTALLY to avoid causing scratches to the front (filter surface).
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.
1-6 (No.YA369)
SECTION 2
SPECIFIC SERVICE INSTRUCTIONS
2.1 FEATURES
T-V LINK ZOOM
When you have a T-V LINK compatible VCR connected to the This function can change the screen size according to the
EXT-2 Terminal on the TV,it is easier to set up the VCR and to picture aspect ratio.
view videos. DIGITAL VNR
PICTURE MODE This function cuts down the amount of noise in the original
This function can adjust the picture settings automatically. picture.
2.2 MAIN DIFFERENCE LIST
Item LT-26A61BJ LT-26A61BU LT-26A61BU/C LT-26A61SJ LT-26A61SU LT-26A61SU/C
PAINT COLOUR BLACK BLACK BLACK SILVER SILVER SILVER
LCD PANLEL UNIT QLD0408-001-JUK QLD0370-002-JUK QLD0408-001-JUK
MAIN PWB QAL0823-001 QAL0822-001 QAL0823-001
Item LT-32A61BJ LT-32A61BU LT-32A61BU/C LT-32A61SJ LT-32A61SU LT-32A61SU/C
PAINT COLOUR BLACK BLACK BLACK SILVER SILVER SILVER
LCD PANLEL UNIT QLD0409-001-JUK QLD0371-001-JUK QLD0409-001-JUK
MAIN PWB QAL0825-001 QAL0824-001 QAL0825-001
2.3 21-PIN EURO CONNECTOR (SCART) : EXT-1 / EXT-2
Pin No. Signal designation Matching value EXT-1 EXT-2
1 AUDIO R output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT)
2 AUDIO R input 500mV(rms) (Nominal), High impedance Used (R1) Used (R2)
3 AUDIO L output 500mV(rms) (Nominal), Low impedance Used (TV OUT) Used (LINE OUT)
4 AUDIO GND Used Used
5 GND (B) Used Used
6 AUDIO L input 500mV(rms) (Nominal), High impedance Used (L1) Used (L2)
7 B input 700mV(B-W), 75 Used Used
8 FUNCTION SW Low : 0V-3V Used Used
(SLOW SW) High : 8V-12V, High impedance
9 GND (G) Used Used
10 SCL / T-V LINK Not used Used
(SCL2 / TV-LINK)
11 G input 700mV(B-W), 75 Used Used
12 SDA Not used Used (SDA2)
13 GND (R) Used Used
14 GND (YS) Used Not used
15 R / C input R : 700mV(B-W), 75 Used (R) Used (C2/R)
C : 300mV(P-P), 75
16 Ys input (FAST SW) Low : 0V-0.4V, High : 1V-3V, 75 Used Used
17 GND (VIDEO output) Used Used
18 GND (VIDEO input) Used Used
19 VIDEO output 1V(P-P) (Negative sync), 75 Used (TV OUT) Used (LINE OUT)
20 VIDEO / Y input 1V(P-P) (Negative sync), 75 Used Used
21 COMMON GND Used Used
(P-P= Peak to Peak, B-W= Blanking to white peak)
[Pin assignment]
20 18 16 14 12 10 8 6 4 2
21 19 17 15 13 11 9 7 5 3 1
(No.YA369)1-7
2.4 HOW TO IDENTIFY MODELS
BJ, BU, SJ and SU models : "AE" is added to the serial No. after at the Rating label.
BU/C and SU/C models : "CE" is added to the serial No. after at the Rating label.
MODEL No. LT-26A60BJ LT-32A60BJ
LT-26A60BU LT-32A60BU
LT-26A60SJ LT-32A60SJ
LT-26A60SU LT-32A60SU
AE
SERIAL NO.
CE
Indicated
2.5 TECHNICAL INFORMATION
2.5.1 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.
2.5.1.1 SPECIFICATIONS
The following table shows the specifications of this unit.
Specifications
Item 26V-TYPE LCD PANEL UNIT 32V-TYPE LCD PANEL UNIT
QLD0370-002-JUK QLD0408-001-JUK QLD0371-001-JUK QLD0409-001-JUK
Maximum dimensions ( W × H × D ) 626 mm × 373 mm × 52 mm 626 mm × 373 mm × 47.5 mm 760 mm × 450 mm × 50 mm 760 mm × 450 mm × 45 mm
Weight 4.7 kg 4.2 kg 7.0 kg 7.2 kg
Effective screen size Diagonal: 660 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: 0.51075mm
Displayed colour 16777216 colours 256 colours for R G and B
Brightness 500cd/m2
Contrast ratio 1000 : 1 800 : 1 1000 : 1 800 : 1
Response time less than 22 ms less than 35 ms less than 22 ms less than 20 ms
View angle (Horizontally) 178° 170°
View angle (Vertically) 178° 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 5V 6.5 V 5V
Power supply voltage in inverter 24 V
Panel interface system LVDS (Low Voltage Differential Signaling)
2.5.1.2 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.
1-8 (No.YA369)
2.5.2 MAIN CPU PIN FUNCTION [U302 : MAIN PWB]
Pin Pin name I/O Function Pin Pin name I/O Function
1 D1 I/O Program ROM data for CPU 51 NC2 - Not used
2 D4 I/O Program ROM data for CPU 52 XTAL2 O 6MHz for system clock
3 D2 I/O Program ROM data for CPU 53 XTAL1 I 6MHz for system clock
4 D3 I/O Program ROM data for CPU 54 NC3 - Not used
5 XROM O This pin must be pulled low to access external ROM. 55 VSSA - GND
6 VDD 2.5 I 2.5V 56 VDDA 2.5 I 2.5V
7 VSS - GND 57 R O R for teletext
8 VDD 3.5 I 3.5V 58 G O G for teletext
9 P0.0 I/O Address/Data for scaler IC 59 B O B for teletext
10 P0.1 I/O Address/Data for scaler IC 60 BLANK/COR O Ys for Teletext
11 P0.2 I/O Address/Data for scaler IC 61 NC4 - Not used
12 P0.3 I/O Address/Data for scaler IC 62 P1.7 O Reset for Scaler IC [H=Reset]
13 P0.4 - Not used 63 NC5 - Not used
14 P0.5 O Address latch Enable 64 WR O Write for memory
15 P0.6 - Not used 65 RD O Read for memory
16 P0.7 - Not used 66 NC6 Not used
17 ENE - Not used 67 A19 O Program ROM address for CPU
18 STOP - Not used 68 A18 O Program ROM address for CPU
19 OCF - Not used 69 A16 O Program ROM address for CPU
20 EXTIF - Not used 70 A17 O Program ROM address for CPU
21 CVBS I Video for teletext 71 A15 O Program ROM address for CPU
22 VDDA 2.5 I 2.5V 72 FL_PGM - Test purpose
23 VSSA - GND 73 VDD 2.5 I 2.5V
24 P2.0 I Scart2 ID [H=Detect] 74 VSS - GND
25 P2.1 I key scan data 1 75 VDD 3.3 I 3.3V
26 P2.2 I key scan data 2 76 A14 O Program ROM address for CPU
27 P2.3 I Scaet1 ID [H=Detect] 77 A12 O Program ROM address for CPU
28 NC1 - Not used 78 A13 O Program ROM address for CPU
29 HS/SSC I Horizontal sync 79 A7 O Program ROM address for CPU
30 VS I Vertical sync 80 FL_RST - Test purpose
31 P3.0 O Data Read for Scaler IC 81 A8 O Program ROM address for CPU
32 P3.1 O Comunication for adjustment [H=TXD] 82 A6 O Program ROM address for CPU
33 P3.2 I TV-Link in 83 A9 O Program ROM address for CPU
34 P3.3 I Remote control 84 A5 O Program ROM address for CPU
35 P3.4 I/O I2C bus Data(for EEPROM) 85 A11 O Program ROM address for CPU
36 P3.5 O I2C bus Clock(for EEPROM) 86 A4 O Program ROM address for CPU
37 P3.6 O Data Write for Scaler IC 87 ALE O Address Latch Enable
38 P3.7 I Comunication for adjustment [H=RXD] 88 PSEN O Program Store Enable
39 VSS - GND 89 A3 O Program ROM address for CPU
40 VDD 3.3 I 3.3V 90 A10 O Program ROM address for CPU
41 P1.0 O RGB Select [L=SCART1, H=SCART2] 91 VSS - GND
42 P1.1 I Headphone Ident [L=Detect] 92 VDD 3.3 I 3.3V
43 P1.2 I/O I2C bus Data(for inter IC) 93 A2 O Program ROM address for CPU
44 P1.3 O I2C bus Clock(for inter IC) 94 A1 O Program ROM address for CPU
45 P1.4 O Reset for inter IC [L=Reset] 95 FL_CE - Test purpose
46 P1.5 I PC Detect [L=Detect] 96 D7 I/O Program ROM data for CPU
47 P1.6 O Memory Pack I2C S/W [L=Detect] 97 A0 O Program ROM address for CPU
48 P4.2 O Main power control [L=ON, H=OFF] 98 D6 I/O Program ROM data for CPU
49 P4.3 O TV-Link out 99 D0 I/O Program ROM data for CPU
50 RST O Reset [L=Reset] 100 D5 I/O Program ROM data for CPU
(No.YA369)1-9
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 3.1.6 REMOVING THE LED PWB
(1) Remove the JACK COVER. · Remove the STAND.
(2) Remove the STAND COVER by sliding it in the direction of · Remove the REAR COVER.
an arrow. (1) Remove the 2 screws [R], then remove the LED PWB.
(3) Remove the 2 screws [A], then remove the STAND
COVER. 3.1.7 REMOVING THE SPEAKER
(4) Remove the 2 screws [B] and 2 screws [C], then remove · Remove the STAND.
the STAND. · Remove the REAR COVER.
(1) Remove the 6 screws [S], then remove the SPEAKER (L/
3.1.2 REMOVING THE REAR COVER R).
· Remove the STAND. CAUTION:
(1) Remove the 8 screws [D], 1 screw [E] and 2 screws [F], Please do not disassembly the SPEAKER.
then remove the REAR COVER. When the speaker is decomposed, the performance cannot be
kept.
3.1.3 REMOVING THE POWER PWB
· Remove the STAND. 3.1.8 REMOVING THE LCD PANEL UNIT
· Remove the REAR COVER. · Remove the STAND.
(1) Remove the 4 screws [G] and 1 screw [H], then remove the · Remove the REAR COVER.
TERMINAL BASE. · Remove the TERMINAL BASE.
(2) Remove the 8 screws [J], then remove the BACK · Remove the BACK BRACKET.
BRACKET. (1) Remove the 6 screws [T], then remove the MAIN BASE.
(3) Remove the 6 screws [K], then remove the POWER PWB (2) Remove the 6 screws [U], then remove the FRONT
SHIELD. PANEL.
(4) Remove the 5 screws [L], then remove the POWER PWB. (3) Remove the 2 screws [V], then remove the TOP FRAME.
(4) Remove the 2 screws [W], then remove the BOTTOM
3.1.4 REMOVING THE MAIN PWB FRAME.
· Remove the STAND.
· Remove the REAR COVER. NOTE:
· Remove the TERMINAL BASE. · Pay special attention not to break or damage on the FRONT
· Remove the BACK BRACKET. PANEL.
· Remove the POWER PWB SHIELD. · The LCD PANEL UNIT is fixed to the FRONT PAMEL (at the
(1) Remove the 7 screws [M] and 2 screws [N], then remove back side)by using double-side adhesive tapes. To remove
the MAIN PWB SHIELD. the LCD PANEL UNIT, remove the adhesive tape on the
(2) Remove the 6 screws [P], then remove the MAIN PWB. FRONT PANEL slowly.
3.1.5 REMOVING THE KEY PWB
· Remove the STAND.
· Remove the REAR COVER.
(1) Remove the 2 screws [Q], then remove the KEY PWB.
1-10 (No.YA369)
C A
B J
JACK COVER
J
F
E BACK BRACKET
STAND
D
MAIN PWB SHIELD
M
REAR COVER
P
K
MAIN PWB
P G N
POWER PWB
J
TERMINAL BASE
INSULATOR POWER CORD
T MAIN BASE H
S
POWER PWB
SHIELD
T
U S
V
TOP FRAME
SPEAKER
V
SPEAKER
U BOTTOM FRAME
W
R
LCD PANEL UNIT
LED PWB
Q
CONTROL PWB
FRONT PANEL
This exploded view shows the LT-32A61
series. LT-26A61 series slightly differs from
this exploded view, however it can be KNOB BASE
disassembled in the same procedure as LT-
26X506.
Fig.1
(No.YA369)1-11
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 SETTING ITEM
NOTE: Setting
As self check feature is not used in this TV, Setting items Settings Item No.
items
"2.SELF_CHECK" cannot be selected (screen display
1.ADJUST Video system setting -1 Adjust S001 - S043
only).
Video system setting -2 Fixed M001 - M009
SERVICE MODE SCREEN Audio System Setting Fixed A001 - A003
Video system setting -3 Fixed D001 - D051
SERVICE MENU
1.ADJUST Video system setting -4 Fixed SD01 - SD15
2.SELF_CHECK Not used
3.I2C STOP
4.OPTION (Display only) Video system setting -5 Fixed DD07 - DD31
1.OPTION Option Setting Fixed 0001 - 0004
1. ADJUST
S001 5I R OF 126
PAL50 FULL STD H
4. OPTION
[Do not adjust]
0001 GAMMA TABLE 000
Fig.1
1-12 (No.YA369)
3.2.3 SETTINGS OF FACTORY SHIPMENT
3.2.3.1 BUTTON OPERATION 3.2.3.2 REMOTE CONTROL DIRECT OPERATION
Setting item Setting position Setting item Setting position
POWER Off CHANNEL PR1
CHANNEL PR1 VOLUME 10
VOLUME 10 ZOOM PANORAMIC
TV/AV TV 3D SOUND OFF
3.2.3.3 REMOTE CONTROL MENU OPERATION
(1) PICTURE (4) FEATURES
Setting item Setting position Setting item Setting position
PICTURE MODE BRIGHT SLEEP TIMER OFF
COLOUR TEMP. COOL CHILD LOCK ID NO.0000, All CH off
FEATURES APPEARANCE TYPE D
DIGITAL VNR AUTO (LOW) BLUE BACK ON
COLOUR SYSTEM TV Depends on PR/CH FAVOURITE SETTING Reset
EXT AUTO
(5) SET UP
4:3 AUTO ASPECT PANORAMIC
Setting item Setting position
(2) SOUND AUTO PROGRAM TV channel automatically set
Setting item Setting position EDIT/MANUAL PRESET CH only
STEREO / I·II Stereo sound LANGUAGE ENGLISH
BASS Centre DECODER (EXT-2) OFF
TREBLE Centre EXT SETTING
BALANCE Centre S-IN BLANK
3D SOUND OFF ID BLANK
DUBBING EXT-1 EXT-2
(No.YA369)1-13
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 2. How to install Chip parts
[Resistors, capacitors, etc.] [Resistors, capacitors, etc.]
(1) As shown in the figure, push the part with tweezers and (1) Apply solder to the pattern as indicated in the figure.
alternately melt the solder at each end.
(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.
(2) Shift with the tweezers and remove the chip part.
[Transistors, diodes, variable resistors, etc.]
[Transistors, diodes, variable resistors, etc.]
(1) Apply solder to the pattern as indicated in the figure.
(1) Apply extra solder to each lead. (2) Grasp the chip part with tweezers and place it on the
solder.
(3) First solder lead A as indicated in the figure.
SOLDER SOLDER
A
(2) As shown in the figure, push the part with tweezers and
alternately melt the solder at each lead. Shift and remove B
the chip part.
C
(4) Then solder leads B and C.
A
B
NOTE :
After removing the part, remove remaining solder from the C
pattern.
1-14 (No.YA369)
SECTION 4
ADJUSTMENT
4.1 ADJUSTMENT PREPARATION 4.2 PRESET SETTING BEFORE ADJUSTMENTS
(1) The adjustment using the REMOTE CONTROL UNIT is Unless otherwise specified in the adjustment items, preset the
made on the basis of the initial setting values. The following functions with the REMOTE CONTROL UNIT.
setting values which adjust the screen to the optimum
Setting item Settings position
condition can be different from the initial setting
values. PICTURE MODE STANDARD
(2) Make sure that connection is correctly made AC to AC PICTURE adjustments Centre
power source.
(3) Turn on the power of the TV and measuring instruments for COLOUR TEMP. NORMAL
warming up for at least 30 minutes before starting
adjustments. 4.3 MEASURING INSTRUMENT AND FIXTURES
(4) If the receive or input signal is not specified, use the most · Signal generator (Pattern generator)[PAL]
appropriate signal for adjustment. · Remote control unit
(5) Never touch the parts (such as variable resistors,
transformers and condensers) not shown in the adjustment
items of this service adjustment. 4.4 ADJUSTMENT ITEMS
4.5 BASIC OPERATION OF SERVICE MODE
4.5.1 HOW TO ENTER THE SERVICE MODE 4.5.3 CHANGE AND MEMORY OF SETTING VALUE
(1) Press [INFORMATION] key and [MUTING] key on the SELECTION OF SETTING ITEM
remote control unit simultaneously to enter the SERVICE · [FUNCTION / ] key.
MODE SCREEN. (Fig.1) For scrolling up / down the setting items.
CHANGE OF SETTING VALUE (DATA)
SERVICE MODE SCREEN · [FUNCTION / ] key.
For scrolling up / down the setting values.
MEMORY OF SETTING VALUE (DATA)
SERVICE MENU
1.ADJUST Changed setting value is memorized by pressing [MUTING]
2.SELF_CHECK key.
3.I2C STOP
4.OPTION
Not used 4.5.4 SERVICE MODE SELECT KEY LOCATION
(Display only)
MUTING
Fig.1 NUMBER VCR/TV/DVD
switch
NOTE:
· As self check feature is not used in this TV,
"2.SELF_CHECK" cannot be selected (screen display
only). INFORMATION
· Before entering the SERVICE MODE, confirm that the
setting of VCR/TV/DVD switch is at the "TV" side. If the MENU
switches have not been properly set, you cannot enter the
SERVICE MODE.
FUNCTION / FUNCTION /
4.5.2 HOW TO EXIT THE SERVICE MODE
Press the [MENU] key to exit the Service mode.
(No.YA369)1-15
4.5.5 ADJUSTMENT MODE (4) WHITE BALANCE
This mode is used to adjust the VIDEO CIRCUIT. State of the colour temperature is displayed.
4.5.5.1 HOW TO ENTER THE ADJUSTMENT MODE NOTE:
When the SERVICE MENU SCREEN of SERVICE MODE is In ADJUSTMENT MODE, the colour temperature can be set
displayed, press [1] key to enter the ADJUSTMENT MODE only to "NORMAL". When it is entered to ADJUSTMENT
(Fig.2). MODE, it is automatically changed to "NORMAL", even if
NOTE: the setting is in other colour temperature.
· When a number key other than the [1] key is pressed in the (5) SETTING ITEM NAME
SERVICE MODE SCREEN, the other relevant screen may Setting item name are displayed. The setting item numbers to
be displayed. be displayed are listed below.
This is not used in the adjustment procedure. Press the
Item No. Setting item
[MENU] key to return to the SERVICE MODE SCREEN.
S001 - S043 Video system setting -1
4.5.5.2 DESCRIPTION OF STATUS DISPLAY M001 - M009 Video system setting -2
SETTINGITEM No. SETTING ITEM SETTING VALUE (DATA) A001 - A003 Audio System Setting
D001 - D051 Video system setting -3
SD01 - SD15 Video system setting -4
S001 5I R OF 126
PAL50 FULL STD H DD07 - DD31 Video system setting -5
(6) SETTING ITEM NO.
Setting item numbers are displayed. For the setting item
names to be displayed, refer to "INITIAL SETTING VALUES
IN THE SERVICE MODE".
(7) SETTING VALUE (DATA)
The SETTING VALUE is displayed.
SIGNAL SYSTEM ZOOM MODE PICTURE MODE COLOUR TEMP.
4.5.6 OPTION MODE [Do not adjust]
(1) SIGNAL SYSTEM Display of optin data setting.
The signal displayed on the screen is displayed.
4.5.6.1 DESCRIPTION OF STATUS DISPLAY
PAL50 : PAL50Hz (Composite / S-video)
PAL60 : PAL60Hz (Composite / S-video) OPTION MODE SCREEN
SECAM : SECAM SETTINGITEM No. SETTING ITEM SETTING VALUE (DATA)
NTSC3 : NTSC3.58
NTSC4 : NTSC4.43
525I : 525i (Component) 0001 GAMMA TABLE 000
525P : 525p
625I : 625i (Component)
625P : 625p
750P6 : 750p 60Hz
PCVGA : PC (VGA)
PCXGA : PC (XGA)
(2) ZOOM MODE
State of the screen mode is displayed. (1) SETTING ITEM NAME
NOTE: Setting item name are displayed. The setting item numbers to
In ADJUSTMENT MODE, the screen mode can be set only be displayed are listed below.
to "FULL". When it is entered to ADJUSTMENT MODE, it is
Item No. Setting item
automatically changed to "FULL", even if the setting is in
other screen mode. 0001 - 0004 optin data setting [Do not adjust]
(3) PICTURE MODE
State of the picture mode is displayed. (2) SETTING ITEM NO.
Setting item numbers are displayed. For the setting item
NOTE: names to be displayed, refer to "INITIAL SETTING VALUES
In ADJUSTMENT MODE, the picture mode can be set only IN THE SERVICE MODE".
to "STANDARD". When it is entered to ADJUSTMENT
MODE, it is automatically changed to "STANDARD", even (3) SETTING VALUE (DATA)
if the setting is in other picture mode. The SETTING VALUE is displayed.
1-16 (No.YA369)
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 ADJUSTMENT MODE
4.6.1.1 VIDEO SYSTEM SETTING -1 4.6.1.2 VIDEO SYSTEM SETTING -2 (Fixed values)
Item No. Item name Variable range Setting value Item No. Item name Variable range Setting value
S001 5I R OF 000 - 255 127 M001 MV CON 000 - 255 105
S002 5I G OF 000 - 255 127