JVC LT-Z26SX4B Service Manual

YA208200412

SERVICE MANUAL

WIDE LCD PANEL TELEVISION

LT-Z26SX4B, LT-Z26SX4B/A, LT-Z26SX4B

/S, LT-Z26SX4S/S

BASIC CHASSIS

TABLE OF CONTENTS

1 PRECAUTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

2 SPECIFIC SERVICE INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6

3 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

4 ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16

5 TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23

No.YA208

2004/12

SPECIFICATION

Items Contents

Dimensions ( W × H × D ) 70.3cm × 55.5 cm × 30.0 cm [Included stand]

70.3cm × 49.1 cm × 10.7 cm [TV only]

Mass 16.1kg [Included stand]

12.8kg [TV only]

Power Input AC110V - AC240 V, 50 Hz / 60 Hz

Power Consumption 125W (Standby: 2.8W)

TV RF System B, G, I, D, K, K1, M

Colour System PAL / SECAM / NTSC 3.58 / NTSC 4.43

Stereo System A2 (B/G, D/K), NICAM (B/G, I, D/K)

Teletext System FLOF (Fastext), TOP, WST (World Standard System)

Receiving Frequency

Intermediate Frequency VIF

Colour Sub Carrier

LCD panel 26V-inch wide aspect (16:9)

Screen Size Diagonal : 66cm (H:57.6cm × V : 32.4cm) Display Pixels Horizontal : 1366 dots × Vertical : 768 dots (W-XGA)

Audio Power Output 10W + 10W

Speaker 6.6cm, round type × 2 (Oblique corn) Aerial terminal (VHF/UHF) 75Ω unbalanced, coaxial

Video / Audio Input-1/2/3

Video / Audio Output S-Video

PC (RGB) Input D-sub 15pin × 1

Audio Output 500mV (rms), Low impedance, RCA pin jack × 2 Headphone 3.5mm stereo mini jack × 1 Remote Control Unit RM-C1830H (AA/R6 dry cell battery × 2)

Design & specifications are subject to change without notice.

Component Video

VHF Low

VHF High

UHF

CATV

SIF

PAL

SECAM

NTSC

[Input-1/3]

1125i

625p / 525p

625i / 525i

S-Video

[Input-1/2]

Video Audio

46.25MHz - 168.25MHz

175.25MHz - 463.25MHz

471.25MHz - 863.25MHz Mid (X - Z+2, S1 - S10) / Super (S11 - S20) / Hyper (S21 - S41) bands

38.0MHz (B, G, I, D, K, L)

32.26MHz (5.74MHz: B), 32.15MHz (5.85MHz: G), 31.45MHz (6.55MHz: I)

31.75MHz (6.25MHz: D), 32.15MHz (5.85MHz: K)

4.43MHz

4.40625MHz / 4.25MHz

3.58MHz / 4.43MHz

Component connector (2-row 14-pn × 1) (Input-1) RCA pin jack × 3 (Input-3) Y : 1V (p-p) (Sync signal: ±0.35V(p-p), 3-value sync.), 75 Ω Pb/Pr : ±0.35V(p-p), 75 Ω Y : 1V (p-p), Positive (Negative sync provided), 75 Ω Pb/Pr : 0.7V(p-p), 75 Ω Mini-DIN 4 pin connector × 2 Y: 1V (p-p), Positive (Negative sync provided), 75 Ω C: 0.286V (p-p) (Burst signal), 75 Ω 1V (p-p), Positive (Negative sync provided), 75 Ω, RCA pin jack × 3 500mV (rms), High impedance, RCA pin jack × 6

Mini-DIN 4 pin connector × 1 Y: 1V (p-p), Positive (Negative sync provided), 75 Ω C: 0.286V (p-p) (Burst signal), 75 Ω 1V (p-p), Positive (Negative sync provided), 75 Ω, RCA pin jack × 1 500mV (rms), Low impedance, RCA pin jack × 2

R/G/B : 0.7V (p-p), 75Ω

HD / VD : 1V (p-p) to 5V (p-p), high impedance < Available signal >

VGA : 640 pixels × 480 pixels (Horizontal : 31.5kHz / Vertical : 60Hz) XGA : 1024 pixels × 768 pixels (Horizontal : 48.4kHz / Vertical : 60Hz)

1-2 (No.YA208)

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 1000Ω per 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)

0.15 F AC-TYPE

GOOD EARTH GROUND

1500 10W

PLACE THIS PROBE ON EACH EXPOSED ME TAL PAR T

(No.YA208)1-3

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.

Ventilation hole

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. Use the supplied screws to firmly attach the supplied hooks (OPTION) to the back of the TV, and use commercially available cord to fix the TV to rigid components such as walls and columns.

Wall

Hook

The hook for fall prevention(option)

It fixes in a band.

TV Stand

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.

150 mm

200 mm

150 mm

200 mm

50 mm

*Diagram differs from actual appearance.

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.

1-4 (No.YA208)

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).

(No.YA208)1-5

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 FEATURES

D.I.S.T. (Digital Image Scaling Technology)

This system uses line interpolation to double the number of scanning lines and achieve high resolution, flicker-free picture.

COLOUR MANAGEMENT

This function ensures dull colours are compensated to produce natural hues.

PICTURE MANAGEMENT

This function makes it easier to see the dark areas when a picture has many dark areas, and makes it easier to see the bright areas when a picture has many bright areas.

ZOOM

This function can change the screen size according to the picture aspect ratio.

2.2 MAIN DIFFERENCE LIST

Item LT-Z26SX4B LT-Z26SX4B/A LT-Z26SX4B/S LT-Z26SX4S/S

FRONT PANEL COLOUR BLACK ←←SILVER

POWER CORD Round pin (2-pin) type

SHIELD COVER(DIGITAL SIGNAL PWB)

TOP SHIELD CASE(DIGITAL SIGNAL PWB)

SIDE SHIELD CASE(DIGITAL SIGNAL PWB)

DIGITAL SIGNAL P.W.B SFL0D301A-H2 SFL0D303A-H2 SFL0D302A-H2 ←

Not used ← Used ← Not used Not used Used ← Not used Not used Used ←

DIGITAL VNR

This function cuts down the amount of noise in the original picture.

SUPER DIGIPURE

This function uses the latest in digital technology to give you a natural-looking picture.

PULL DOWN

This function displays a cinema film picture more smoothly and naturally on the screen.

3D CINEMA SOUND

You can enjoy sounds with a widerambience.

Australia pin (2-pin) type

UK pin (3-pin) type ←

1-6 (No.YA208)

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 Specifications Remarks

Maximum dimensions ( W × H × D ) 627mm × 374mm × 52mm

Weight 4.5kg

Effective screen size Diagonal: 660.4mm (H:575.7mm × V : 323.7mm) 26V type

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:0.4215mm, Vertically:0.4215mm

Displayed colour 16777216 colours 256 colours for R, G, and B

Brightness 500cd/m

Contrast ratio 800: 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

Power supply voltage in LCD 6.5V

Power supply voltage in inverter 18V

Panel interface system LVDS (Low Voltage Differential Signaling)

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.

(No.YA208)1-7

2.3.2 MAIN CPU PIN FUNCTION [IC7501 : DIGITAL SIGNAL PWB ASS'Y]

Pin Pin name I/O Function Pin Pin name I/O Function

1 TCK I Test purpose 65 D2 I/O Program ROM data for main CPU 2 TMS I Test purpose 66 D12 I/O Program ROM data for main CPU 3 TDI I Test purpose 67 D10 I/O Program ROM data for main CPU 4 TDO O Test purpose 68 VSS33 - GND 5 P2.8 O Not used 69 VDD33 I 3.3V 6 P2.9 O Blue for OSD 70 D4 I/O Program ROM data for main CPU 7 P2.10 O Blue for OSD 71 D3 I/O Program ROM data for main CPU 8 P2.11 O Blue for OSD 72 D11 I/O Program ROM data for main CPU

9 P2.12 O Blue for OSD 73 RSTIN I Reset 10 P2.13 O Blue for OSD 74 POWER O Sleep state release for chassis CPU [Relese : L] 11 P2.14 I Not used 75 P3.1 O Not used 12 P2.15 O Request for chassis CPU communication 76 REMOCON I Remote control 13 VSS33 - GND 77 P3.3 I Clock for OSD 14 VDD33 I 3.3V 78 P3.4 O Red for OSD 15 P4.5 O Not used 79 P3.5 O Red for OSD 16 A20 O Program ROM address for main CPU 80 P3.6 O Red for OSD 17 A19 O Program ROM address for main CPU 81 P3.7 O Red for OSD 18 A18 O Program ROM address for main CPU 82 MTST O Data transmission for chassis CPU communication 19 A17 O Program ROM address for main CPU 83 MTSR I Data receive for chassis CPU communication 20 VSS25 - GND 84 VSS33 - GND 21 VDD25 I 2.5V 85 VDD33 I 3.3V 22 A16 O Program ROM address for main CPU 86 VSS25 - GND 23 A8 O Program ROM address for main CPU 87 VDD25 I 2.5V 24 A7 O Program ROM address for main CPU 88 TXD0 O Communication for adjustment 25 A9 O Program ROM address for main CPU 89 RXD0 O Communication for adjustment 26 A6 O Program ROM address for main CPU 90 P3.12 O Red for OSD 27 A5 O Program ROM address for main CPU 91 CLK O Clock for chassis CPU communication 28 A10 O Program ROM address for main CPU 92 P3.15 O Green for OSD 29 A11 O Program ROM address for main CPU 93 P5.14 O Green for OSD 30 A12 O Program ROM address for main CPU 94 P5.15 O Green for OSD 31 VSS33 - GND 95 TRIG_IN O Green for OSD 32 VDD33 I 3.3V 96 TRIG_OUT O Green for OSD 33 A4 O Program ROM address for main CPU 97 P6.2 O Green for OSD 34 A3 O Program ROM address for main CPU 98 P6.3 O I 35 A2 O Program ROM address for main CPU 99 P6.4 I/O I 36 A1 O Program ROM address for main CPU 100 P6.5 O Teletext signal select [Analog RGB : H / Digital RGB : L] 37 A0 O Program ROM address for main CPU 101 IRQ O Not used 38 A13 O Program ROM address for main CPU 102 VSYNC I Vertical sync 39 ARAS/A14 O Program ROM address for main CPU 103 HSYNC I Horizontal sync 40 CAS/A15 O Program ROM address for main CPU 104 41 VSS33 - GND 105 BLANK O Ys for OSD / Teletext 42 VDD33 I 3.3V 106 VDD33 I 3.3V 43 MEMCLK O Clock for memory 107 VSS33 - GND 44 CSSDRAM O Chip select for memory 108 XTAL1 I 6MHz for system clock 45 CLKEN O Clock enable for memory 109 XTAL2 O 6MHz for system clock 46 CSROM O Chip select for memory 110 VSSA - GND 47 RD O Read for memory 111 VDDA I 2.5V 48 UDQM O Control buffer of memory 112 R O R for OSD / Teletext 49 LDQM O Control buffer of memory 113 G O G for OSD / Teletext 50 WR O Write for memory 114 B O B for OSD / Teletext 51 D15 I/O Program ROM data for main CPU 115 VSSA - GND 52 VSS33 - GND 116 VDDA I 2.5V 53 VDD33 I 3.3V 117 CVBS2 I Video for Teletext 54 D7 I/O Program ROM data for main CPU 118 VSSA - GND 55 D0 I/O Program ROM data for main CPU 119 VDDA I 2.5V 56 D14 I/O Program ROM data for main CPU 120 CVBS1B I Video for Teletext 57 D8 I/O Program ROM data for main CPU 121 CVBS1A I Video for Teletext 58 D6 I/O Program ROM data for main CPU 122 VSSA - GND 59 D1 I/O Program ROM data for main CPU 123 VDDA I 2.5V 60 VSS33 - GND 124 KEY1 I Key scan data 1 [ON : H] 61 VDD33 I 3.3V 125 KEY2 I Key scan data 2 [ON : H] 62 D13 I/O Program ROM data for main CPU 126 MECA_SW I Main power ON / OFF control [ON : L] 63 D9 I/O Program ROM data for main CPU 127 P5.3 I Not used 64 D5 I/O Program ROM data for main CPU 128 TMODE I Test purpose

COR/RSTOUT

C bus clock (for main memory)

C bus Data (for main memory)

O Not used

1-8 (No.YA208)

2.3.3 SUB (CHASSIS) CPU PIN FUNCTION [IC7001 : DIGITAL SIGNAL PWB ASS'Y]

Pin Pin name I/O Function Pin Pin name I/O Function

1 LB_PRO O Not used 51 BS_TXD O 2 P_MU O Picture muting [Muting = H] 52 BS_RXD I Not used : Data receive for digital tuner communication 3 JP_CSB O Not used (NC) 53 NC O Not used (NC) 4 A_MU O Audio muting [Muting = H] 54 VREF+ I 3.3V power supply 5 M_MU O Audio muting (for AUDIO OUT) [Muting = H] 55 PDP_TX O 6 PC_SEL O RGB(PC) INPUT select 56 PDP_RX I Data receive for SUB (DRIVE) CPU communication 7 ON_TIMER O POWER INDICATOR (LED) brightness [LOW = L] 57 SDA0 I/O Data for Inter IC (serial) bus : EEP-ROM (IC7002) 8 ILA0 O Not used : LCD back light lighting 58 SCL0 O Clock for Inter IC (serial) bus : EEP-ROM (IC7002)

9 ILA1 O Not used : LCD panel overshoot refresh timing 59 SDA_DVI I/O 10 ILA2 O Not used 60 SCL_DVI O 11 POW_LED O POWER LED lighting [ON = H] 61 AVSS - GND 12 WORD O Not used 62 DIGII_PHOT I 13 MI_CK I Clock for main CPU communication 63 AGC I Not used 14 MI_TX I Data receive for main CPU communication 64 EXT_YS1 I Not used 15 MI_RX O Data transmission for MAIN CPU communication 65 EXT_YS2 I Not used 16 MI_REQ O 17 VDD I 3.3V power supply 67 DIGI_PRO O Not used : For DIGITAL-IN (HDMI) 18 FOSC O Not used (NC) 68 GCR_RST O Not used (NC) 19 VSS - GND 69 GR_ON O Not used (NC) 20 X1 I Not used : Low speed oscillatior 70 SYNC_SEL O Not used : Sync select for digital tuner 21 X0 O Not used : Low speed oscillatior 71 NC O Not used (NC) 22 VDD I 3.3V power supply 72 NC O Not used (NC) 23 OSC1 I System clock osillation (crystal) : 16MHz 73 SBD5 I/O 24 OSC0 O System clock osillation (crystal) : 16MHz 74 SBT5 I 25 MODE I Single chip mode 75 NMI I 3.3V power supply 26 BS1.5CTL O Not used : Digital tuner power / reset control 76 COMP I Not used : AV COMPULINK lll control 27 A92RES O 28 BS_RST O Not used: Reset for Digital tuner power / reset control 78 VSYNC I V. sync pulse 29 LIP_RST O Not used: Reset for Sound delay (Lip sync) 79 WAKE I Reset for sub(chassis) CPU 30 SOFT_OFF O Not used 80 31 VMUTE I Not used: Picture muting request from digital tuner 81 NC O Not used (NC) 32 VOUTENB O Not used: Video cutoff for digital tuner 82 RST I Reset for MAIN CPU [Reset = L] 33 MDR_CON I Not used: System cable connection monitor for PDP 83 VDD I 3.3V power supply 34 AVDD I 3.3V power supply 84 SCL3A O Clock for Inter IC (serial) bus control 35 BS_POW O Not used : Digital tuner power control 85 SDA3A I/O Data for Inter IC (serial) bus control

DsyncSW2

36 37 LB_POW O Not used : Power control for low bias line 87 SDA3B I/O Data for Inter IC (serial) bus control 38 NC O Not used (NC) 88 39 HOTPLUG I 40 MECA_SW I Mechanical monitor for POWER switch [Push = L] 90 DIGI_INT I Not used : Reset for HDMI process [Reset = L ] 41 MAIN_POW O Main power control [ON = L] 91 DVI_RST O Not used : Reset for DVI format conversion 42 MSP_RST O AUDIO OUT output mode select [VARIABLE = L] 92 VSS - GND 43 VREF- I Not used 93 SCL5055 O 44 AFT2 I Not used : AFT voltage for sub tuner 94 45 AFT1 I AFT voltage for VHF/UHF tuner 95 SDA5055 I/O Data for Inter IC (serial) bus : JCC5055 (DIST process) 46 KEY2 I Key scan data for front switch (MENU/CH+/CH-) 96 47 KEY1 I Key scan data for front switch (VOL+/VOL-) 97 NC O Not used (NC) 48 NC O Not used (NC) 98 15K/OTH O Main video select [Fixed = H] 49 NC O Not used (NC) 99 DsyncSW1 O 50 AC_IN I AC power pulse for timer clock 100 57 BUSY I Busy monitor for JCC5057 (New DIST process)

Data request for main CPU communication [Request = L]

Reset for IC1001(3D YC SEP / COLOUR DEMODULAT) [Reset = H]

O Sync select for DIGITAL-IN [Cotrolled with 99-pin] 86 SCL3B O Clock for Inter IC (serial) bus control

Not used : Video communiation monitor for receiver unit (PDP)

66 VDD I 3.3V power supply

77 REMO I Remote control

POWERGOOD

DIGI_SYNCSEL

89 DIGI_LRSW O Not used : For DIGITAL-IN (HDMI)

VFORMATSEL

OSD_MODE_SEL

Not used : Data transmission for digital tuner communication

Data transmission for SUB (DRIVE) CPU communication

Not used : Data for Inter IC (serial) bus for panel communication Not used : Clock for Inter IC (serial) bus for panel communication

Not used: Photo sensor for DIGITAL-IN illegal copy protection

Not used : Data for writing on board (connect CN01P : for Frash ROM type) Not used : Clock for writing on board (connect CN01P : for Frash ROM type)

I Power error detection [NG = H]

O Not used

Clock for Inter IC (serial) bus : JCC5055 (DIST process)

O Not used : Digital tuner clock control

O Not used : OSD mode select

Not used : Sync select for DIGITAL-IN [Cotrolled with 36-pin]

(No.YA208)1-9

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

NOTE:

• 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 (Fig.1)

(1) Remove the 2 screws [A], then remove the STAND

COVER.

(2) Remove the 4 screws [B], then remove the STAND.

3.1.2 REMOVING THE REAR COVER (Fig.1)

• Remove the STAND. (1) Remove the JACK COVER (L/R). (2) Remove the 7 screws [C], the 4 screws [D], and the 1

screws [E] .

(3) Remove the REAR COVER.

3.1.3 REMOVING THE POWER PWB / REGULATOR PWB

(Fig.1)

• Remove the STAND.

• Remove the REAR COVER. (1) Remove the 5 screws [F], then remove the FAN

BRACKET.

(2) Remove the 1 screw [G], then remove the POWER CORD

HOLDER. (3) Remove the POWER CORD from the POWER PWB. (4) Remove the REGULATOR PWB. (5) Remove the 5 screw [H], then remove the POWER PWB.

3.1.4 REMOVING THE ANALOG SYGNAL PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

• Remove the FAN BRACKET. (1) Remove the 6 screws [J] then remove the TERMINAL

BASE.

(2) Remove the 6 screws [K] and the 2 hex screws [W] then

remove the ANALOG SYGNAL PWB.

3.1.6 REMOVING THE RECEIVER PWB / CONNECTOR PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

(1) Remove the 3 screws [U], then remove the TUNER BASE

and SIDE SHIELD CASE.

(2) Remove the 4 screws [O] then remove the RECEIVER

PWB.

(3) Remove the 4 screws [P] then remove the RECEIVER

PWB BRACKET.

(4) Remove the 2 screws [Q] then remove the CONNECTOR

PWB.

3.1.7 REMOVING THE DIGITAL SIGNAL PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

• Remove the TUNER BASE.

(1) Remove the 9 screws [S] and the 3screws [T], then

remove the SHIELD COVER.

(2) Remove the 5 screws [V], then remove the DIGITAL

SIGNAL PWB.

3.1.8 REMOVING THE SPEAKER (Fig.2)

• Remove the STAND.

• Remove the REAR COVER.

(1) Remove the 5 screws [a], then remove the SPEAKER

BOX. (2) Remove the 4 screws [b], then remove the SPEAKER (L /R). (3) Remove the 4 screws [c], then remove the DUCT(L/R).

NOTE:

Since the speaker is attached in a certain direction, attach the speaker in the same correct direction as it has been attached.

3.1.5 REMOVING THE FRONT CONTROL PWB CONTROL / FRONT SENSOR PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

(1) Remove the 2 screws [L], then remove the CONTROL

KNOB ASSY.

(2) Remove the 2 screws [M], then remove the FRONT

CONTROL PWB.

(3) Remove the FRONT SENSOR PWB.

1-10 (No.YA208)

3.1.9 REMOVING THE LCD PANEL UNIT (Fig.2)

• Remove the STAND.

• Remove the REAR COVER. (1) Remove the 6 screws [d] and the 4 screws [e]. (2) Remove the LCD PANEL UNIT. (3) Remove the 7 screws [f]. then remove the MAIN BASE. (4) Remove the 2 screws [g]. then remove the TOP FRAME. (5) Remove the 2 screws [h]. then remove the BOTTOM

FRAME.

REAR COVER

REGULATOR PWB

JACK COVER

POWER CORD

RECEIVER PWB

STAND COVER

JACK COVER

STAND

FAN BRACKET

TUNER BASE

SHIELD COVER

[LT-Z26SX4B/S, LT-Z26SX4S/S]

INSULATOR

POWER PWB

ANALOG SIGNAL PWB

TERMINAL BASE

FRONT SENSOR PWB

POWER CORD

HOLDER

FRONT CONTROL PWB

CONTROL KNOB ASSY

RECEIVER PWB BRACKET

CONNECTOR PWB

Fig.1

SIDE SHIELD CASE

TOP SHIELD CASE

[LT-Z26SX4B/S, LT-Z26SX4S/S]

DIGITAL SIGNAL PWB

FRONT

(No.YA208)1-11

MAIN BASE

TOP FRAME

LCD PANEL UNIT

BOTTOM FRAME

SPEAKER BOX

DUCT

DUCT SHEET

DUCT

SPEAKER

1-12 (No.YA208)

FRONT PANEL

FRONT

DUCT SHEET

SPEAKER

Fig.2

3.2 MEMORY IC REPLACEMENT

S001 PREPARE 0 PAL50 FULL STD H

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

• 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

MAIN MENU SCREEN

SETTING ITEM

Setting items Settings Item No.

Video system setting Adjust S001 - S039

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

Audio system setting Fixed T001 - T010

Panel control system setting Fixed P001 - P010

Drive system setting Fixed D001 - D187

Main CPU system setting Fixed Z001 - Z010

ADJUSTMENT MODE SCREEN

S001 PREPARE 0 PAL50 FULL STD H

Fig.1

(No.YA208)1-13

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

POWER Off

CHANNEL PR1

VOLUME 10

TV/VIDEO TV

STANDBY MODE OFF

3.2.3.3 REMOTE CONTROL MENU OPERATION

(1) PICTURE

Setting item Setting position

PICTURE MODE BRIGHT

WHITE BALANCE COOL

FEATURES

DIGITAL VNR AUTO (LOW)

Super DigiPure AUTO

PULL DOWN AUTO

COLOUR MANAGEMENT ON

PICTURE MANAGEMENT ON

COLOUR SYSTEM MAIN Depends on PR/CH

SUB AUTO

4:3 AUTO ASPECT PANORAMIC

(2) SOUND

Setting item Setting position

STEREO / I•II Stereo sound

BASS Centre

TREBLE Centre

BALANCE Centre

CINEMA SURROUND OFF

A.H.B. ON

BBE ON

CHANNEL PR1

VOLUME 10

ZOOM PANORAMIC

CINEMA OFF

SUB PICTURE VIDEO-1

(4) FEATURES

SLEEP TIMER OFF

APPEARANCE TYPE D

CHILD LOCK ID NO.0000, All CH off

BLUE BACK ON

AUTO SHUTOFF OFF

FAVORITE SETTING RESET

(5) SET UP

AUTO PROGRAM TV channel automatically set

EDIT/MANUAL PRESET CH only

LANGUAGE ENGLISH

VIDEO-1 SETTING COMPONENT

VIDEO-3 SETTING COMPONENT

AI VOLUME ON

TELETEXT LANGUAGE GROUP-1

Setting item Setting position

1-14 (No.YA208)

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.]

(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.

SOLDER

[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 A as indicated in the figure.

(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.

(4) Then solder leads B and C.

(No.YA208)1-15

SECTION 4

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

S001 PREPARE 0 PAL50 FULL STD H

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

warning 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.

Setting item Settings position

PICTURE MODE STANDARD

PICTURE adjustments Centre

WHITE BALANCE MID

DIGITAL VNR MIN

Super DigiPure AUTO

PULL DOWN AUTO

COLOUR MANAGEMENT ON

PICTURE MANAGEMENT ON

SOUND adjustments Centre

BBE OFF

CINEMA SORROUND OFF

A.H.B OFF

ZOOM FULL

4.3 MEASURING INSTRUMENT AND FIXTURES

• Oscilloscope

• Signal generator (Pattern generator) [PAL / 625i / 625p / 1125i(50Hz)]

• Remote control unit

4.4 ADJUSTMENT ITEMS

 VIDEO CIRCUIT

• 625i A-D OFFSET adjustment

• 1125i(50Hz) BRIGHTNESS adjustment

• 1125i(50Hz) A-D OFFSET adjustment

• SUB SCREEN A-D OFFSET adjustment

• WHITE BALANCE (HIGH LIGHT) adjustment

4.5 BASIC OPERATION OF SERVICE MODE

4.5.1 HOW TO ENTER THE SERVICE MODE

(1) Press [DISPLAY] key and [MUTING] key on the remote

control unit simultaneously to enter the SERVICE MODE SCREEN.

(2) In the SERVICE MENU, press the [1] key to display

ADJUSTMENT MODE SCREEN.

NOTE:

• Before entering the SERVICE MODE, confirm that the setting of PIP/TV/DVD switch is at the "TV" side. If the switches have not been properly set, you cannot enter the SERVICE MODE.

• When a number key other than the [1] to [3] key is pressed in the SERVICE MODE 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 MODE SCREEN.

SERVICE MODE SCREEN

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

ADJUSTMENT MODE SCREEN

S001 PREPARE 0 PAL50 FULL STD H

1-16 (No.YA208)

4.5.2 HOW TO EXIT THE SERVICE MODE

Press the [MENU] key to exit the Service mode.

4.5.3 DESCRIPTION OF STATUS DISPLAY

S001 PREPARE 0 PAL50 FULL STD H

SIGNAL SYSTEM

SETTING VALUE (DATA)SETTINGITEM No. SETTING ITEM

ZOOM MODE

PICTURE MODE

COLOUR TEMP.

(1) SIGNAL SYSTEM

The signal displayed on the screen is displayed.

PAL50 : PAL50Hz (Composite / S-video) PAL60 : PAL60Hz (Composite / S-video) SECAM : SECAM NTSC3 : NTSC3.58 NTSC4 : NTSC4.43 525I : 525i (Component) 525P : 525p 625I : 625i (Component) 625P : 625p 1125I5 : 1125i 50Hz 1125I6 : 1125i 60Hz PCVGA : PC (VGA) PCXGA : PC (XGA)

(2) ZOOM MODE

State of the SCREEN SIZE or MULTI PICTURE is displayed.

SINGLE SCREEN

FULL : FULL PANO : PANORAMIC 1609 : 16:9 ZOOM 1609S : 16:9 ZOOM SUBTITLE 1409 : 14:9 ZOOM REGU : REGULAR

MULTI SCREEN

M2 : 2-pictures multi M12 : 12-pictures multi

(3) PICTURE MODE

STD : STANDARD BRI : BRIGHT SOFT : SOFT

(5) SETTING ITEM NAME

Setting item name are displayed. The setting item numbers to be displayed are listed below.

Item No. Setting item

S001 - S039 Video system setting

T001 - T010 Audio system setting

P001 - P010 Panel control system setting

D001 - D187 Drive system setting

Z001 - Z010 Main CPU system setting

(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.

4.5.4 CHANGE AND MEMORY OF SETTING VALUE

SELECTION OF SETTING ITEM

• [FUNCTION /] key.

For scrolling up / down the setting items.

S001... ↔ T001... ↔ P001... ↔ D001... ↔ Z001...

CHANGE OF SETTING VALUE (DATA)

• [FUNCTION /] key.

For scrolling up / down the setting values.

MEMORY OF SETTING VALUE (DATA)

Changed setting value is memorized by pressing [MUTING] key.

4.5.5 SERVICE MODE SELECT KEY LOCATION

MUTING

NUMBER

PIP/TV/DVD switch

ZOOM

FUNCTION /

CINEMA

FUNCTION /

DISPLAY

(4) WHITE BALANCE

L: WARM H : MID, COOL

(No.YA208)1-17

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 4.6.2 AUDIO SYSTEM SETTING (*Fixed values)

Item

S001 PREPARE 0 - 31 0 0 0

S002 NTSC BL 0 - 15 0 0 0

S003 NTSC CNT 0 - 255 36 36 36

S004 NT CR OF 0 - 15 6 6 6

S005 NT CB OF 0 - 15 6 6 6

S006 525i BL 0 - 15 0 0 0

S007 525i CNT 0 - 255 36 36 36

S008 5i CB OF 0 - 15 0 0 0

S009 5i CR OF 0 - 15 0 0 0

S010 5i CR GN 0 - 15 6 6 6

S011 5i CB GN 0 - 15 6 6 6

S012 HD BL 0 - 63 55 55 55

S013 HD CB OF 0 - 63 56 56 56

S014 HD CR OF 0 - 63 58 58 58

S015 RT CONT 0 - 15 7 7 7

S016 RT CB OF 0 - 15 5 5 5

S017 RT CR OF 0 - 15 6 6 6

S018 RT CL GA 0 - 15 12 12 12

S019 PC CL MB 0 - 7 0 0 0

S020 PC CL LB 0 - 31 0 0 0

S021 PC CL MR 0 - 71 0 0 0

S022 PC CL LR 0 - 31 0 0 0

S023 (Not display) 0 - 255 0 0 0

S024 (Not display) 0 - 255 0 0 0

S025 (Not display) 0 - 255 0 0 0

S026 (Not display) 0 - 255 0 0 0

S027 (Not display) 0 - 255 0 0 0

S028 (Not display) 0 - 255 0 0 0

S029 (Not display) 0 - 255 0 0 0

S030 R DRIVE 0 - 255 133 133 133

S031 G DRIVE 0 - 255 130 130 130

S032 B DRIVE 0 - 255 132 132 132

S033 (Not display) 0 - 255 0 0 0

S034 (Not display) 0 - 255 0 0 0

S035 (Not display) 0 - 255 0 0 0

S036 (Not display) 0 - 255 0 0 0

S037 (Not display) 0 - 255 0 0 0

S038 (Not display) 0 - 255 0 0 0

S039 ILA COM 0 - 1 0 0 0

No.

Item name

Variable

range

Setting value

PAL SECAM NTSC

Item

T001 IN LEVEL 0 - 255 0 0 0

T002 LOW SEP 0 - 255 0 0 0

T003 HIGH SEP 0 - 255 0 0 0

T004 AFC 0 - 255 4 4 4

T005 (Not display) 0 - 255 0 0 0

T006 ATT V ON 0 - 1 0 0 0

T007 ATT U ON 0 - 1 0 0 0

T008 ATT C ON 0 - 1 0 0 0

T009 (Not display) 0 - 255 0 0 0

T010 (Not display) 0 - 255 0 0 0

4.6.3 PANEL CONTOROL SYSTEM SETTING (*Fixed values)

Item

P001 TM HOR H 00 - FF 00 00 00

P002 TM HOR L 00 - FF 00 00 00

P003 TM MIN 00 - FF 00 00 00

P004 TEMP0 0 - 255 0 0 0

P005 (Not display) 0 - 255 0 0 0

P006 (Not display) 0 - 255 0 0 0

P007 (Not display) 0 - 255 0 0 0

P008 (Not display) 0 - 255 0 0 0

P009 (Not display) 0 - 255 0 0 0

P010 (Not display) 0 - 255 0 0 0

4.6.4 DRIVE SYSTEM SETTING (*Fixed values)

Item

D001 SLV GN 00 - 3F 15 15 15

D002 SLVH GN 00 - 3F 13 13 13

D003 SLH GN 00 - 3F 15 15 15

D004 SLV Pf 00 - 03 01 01 01

D005 SLH Pf H 00 - 01 01 01 01

D006 SLH Pf L 00 - 03 01 01 01

D007 SL EGCON 00 - 3F 08 08 08

D008 SL EGONF 00 - 01 01 01 01

D009 SL CRGON 00 - 3F 06 06 06

D010 SL CRGON 00 - 01 01 01 01

D011 SL ON OF 00 - 01 01 01 01

D012 SV GN 00 - 3F 1A 1A 1A

D013 SVH GN 00 - 3F 1B 1B 1B

D014 SH GN 00 - 3F 2E 2E 2E

D015 SV Pf 00 - 03 00 00 00

D016 SV PfH 00 - 01 01 01 01

No.

Item name

Variable

range

Variable

range

Variable

range

Setting value

PAL SECAM NTSC

Setting value

PAL SECAM NTSC

Setting value

PAL SECAM NTSC

1-18 (No.YA208)

Item

Item name

No.

D017 SV PfL 00 - 03 00 00 00

D018 SYL CON 00 - 3F 30 30 30

D019 SYL CONF 00 - 01 01 01 01

D020 SYH CON 00 - 3F 00 00 00

D021 SYH CONF 00 - 01 01 01 01

D022 SC CON 00 - 3F 1A 1A 1A

D023 SC CNONF 00 - 01 01 01 01

D024 SPM BLC 00 - 3F 0B 0B 0B

D025 SPM BLCO 00 - 01 01 01 01

D026 SLIM 00 - 3F 20 20 20

D027 SLIMONF 00 - 01 01 01 01

D028 SCRG 00 - 3F 10 10 10

D029 SRGONF 00 - 01 01 01 01

D030 S ONF 00 - 01 01 01 01

D031 pb GN 00 - 3F 15 15 15

D032 pb PfH 00 - 01 01 01 01

D033 pb PfL 00 - 03 00 00 00

D034 pb CRG 00 - 3F 04 04 04

D035 pb CRGON 00 - 01 01 01 01

D036 pb ONF 00 - 01 01 01 01

D037 pr GN 00 - 3F 15 15 15

D038 pr PfH 00 - 01 01 01 01

D039 pr PfL 00 - 03 00 00 00

D040 pr CRG 00 - 3F 05 05 05

D041 pr CRGON 00 - 01 01 01 01

D042 pr ONF 00 - 01 01 01 01

D043 ENH ONF 00 - 01 01 01 01

D044 (Not display) 00 - FF 00 00 00

D045 (Not display) 00 - FF 00 00 00

D046 (Not display) 00 - FF 00 00 00

D047 (Not display) 00 - FF 00 00 00

D048 (Not display) 00 - FF 00 00 00

D049 (Not display) 00 - FF 00 00 00

D050 (Not display) 00 - FF 00 00 00

D051 (Not display) 00 - FF 00 00 00

D052 (Not display) 00 - FF 00 00 00

D053 (Not display) 00 - FF 00 00 00

D054 (Not display) 00 - FF 00 00 00

D055 (Not display) 00 - FF 00 00 00

D056 (Not display) 00 - FF 00 00 00

D057 (Not display) 00 - FF 00 00 00

D058 (Not display) 00 - FF 00 00 00

D059 (Not display) 00 - FF 00 00 00

D060 (Not display) 00 - FF 00 00 00

D061 (Not display) 00 - FF 00 00 00

D062 (Not display) 00 - FF 00 00 00

D063 (Not display) 00 - FF 00 00 00

D064 (Not display) 00 - FF 00 00 00

D065 (Not display) 00 - FF 00 00 00

Variable

range

Setting value

PAL SECAM NTSC

Item

D066 (Not display) 00 - FF 00 00 00

D067 (Not display) 00 - FF 00 00 00

D068 (Not display) 00 - FF 00 00 00

D069 (Not display) 00 - FF 00 00 00

D070 (Not display) 00 - FF 00 00 00

D071 (Not display) 00 - FF 00 00 00

D072 (Not display) 00 - FF 00 00 00

D073 (Not display) 00 - FF 00 00 00

D074 (Not display) 00 - FF 00 00 00

D075 (Not display) 00 - FF 00 00 00

D076 (Not display) 00 - FF 00 00 00

D077 (Not display) 00 - FF 00 00 00

D078 (Not display) 00 - FF 00 00 00

D079 (Not display) 00 - FF 00 00 00

D080 (Not display) 00 - FF 00 00 00

D081 (Not display) 00 - FF 00 00 00

D082 (Not display) 00 - FF 00 00 00

D083 (Not display) 00 - FF 00 00 00

D084 (Not display) 00 - FF 00 00 00

D085 (Not display) 00 - FF 00 00 00

D086 (Not display) 00 - FF 00 00 00

D087 (Not display) 00 - FF 00 00 00

D088 (Not display) 00 - FF 00 00 00

D089 (Not display) 00 - FF 00 00 00

D090 (Not display) 00 - FF 00 00 00

D091 (Not display) 00 - FF 00 00 00

D092 (Not display) 00 - FF 00 00 00

D093 (Not display) 00 - FF 00 00 00

D094 (Not display) 00 - FF 00 00 00

D095 (Not display) 00 - FF 00 00 00

D096 (Not display) 00 - FF 00 00 00

D097 (Not display) 00 - FF 00 00 00

D098 (Not display) 00 - FF 00 00 00

D099 (Not display) 00 - FF 00 00 00

D100 (Not display) 00 - FF 00 00 00

D101 (Not display) 00 - FF 00 00 00

D102 (Not display) 00 - FF 00 00 00

D103 (Not display) 00 - FF 00 00 00

D104 (Not display) 00 - FF 00 00 00

D105 (Not display) 00 - FF 00 00 00

D106 (Not display) 00 - FF 00 00 00

D107 (Not display) 00 - FF 00 00 00

D108 (Not display) 00 - FF 00 00 00

D109 (Not display) 00 - FF 00 00 00

D110 (Not display) 00 - FF 00 00 00

D111 (Not display) 00 - FF 00 00 00

D112 (Not display) 00 - FF 00 00 00

D113 (Not display) 00 - FF 00 00 00

D114 (Not display) 00 - FF 00 00 00

No.

Item name

Variable

range

Setting value

PAL SECAM NTSC

(No.YA208)1-19

Item

D115 (Not display) 00 - FF 00 00 00

D116 (Not display) 00 - FF 00 00 00

D117 (Not display) 00 - FF 00 00 00

D118 (Not display) 00 - FF 00 00 00

D119 (Not display) 00 - FF 00 00 00

D120 (Not display) 00 - FF 00 00 00

D121 (Not display) 00 - FF 00 00 00

D122 (Not display) 00 - FF 00 00 00

D123 (Not display) 00 - FF 00 00 00

D124 (Not display) 00 - FF 00 00 00

D125 (Not display) 00 - FF 00 00 00

D126 (Not display) 00 - FF 00 00 00

D127 (Not display) 00 - FF 00 00 00

D128 (Not display) 00 - FF 00 00 00

D129 (Not display) 00 - FF 00 00 00

D130 (Not display) 00 - FF 00 00 00

D131 (Not display) 00 - FF 00 00 00

D132 (Not display) 00 - FF 00 00 00

D133 (Not display) 00 - FF 00 00 00

D134 (Not display) 00 - FF 00 00 00

D135 (Not display) 00 - FF 00 00 00

D136 (Not display) 00 - FF 00 00 00

D137 (Not display) 00 - FF 00 00 00

D138 (Not display) 00 - FF 00 00 00

D139 (Not display) 00 - FF 00 00 00

D140 (Not display) 00 - FF 00 00 00

D141 (Not display) 00 - FF 00 00 00

D142 (Not display) 00 - FF 00 00 00

D143 (Not display) 00 - FF 00 00 00

D144 (Not display) 00 - FF 00 00 00

D145 (Not display) 00 - FF 00 00 00

D146 (Not display) 00 - FF 00 00 00

D147 (Not display) 00 - FF 00 00 00

D148 (Not display) 00 - FF 00 00 00

D149 (Not display) 00 - FF 00 00 00

D150 (Not display) 00 - FF 00 00 00

D151 (Not display) 00 - FF 00 00 00

D152 (Not display) 00 - FF 00 00 00

D153 (Not display) 00 - FF 00 00 00

D154 (Not display) 00 - FF 00 00 00

D155 (Not display) 00 - FF 00 00 00

D156 (Not display) 00 - FF 00 00 00

D157 (Not display) 00 - FF 00 00 00

D158 (Not display) 00 - FF 00 00 00

D159 (Not display) 00 - FF 00 00 00

D160 (Not display) 00 - FF 00 00 00

D161 (Not display) 00 - FF 00 00 00

D162 (Not display) 00 - FF 00 00 00

D163 (Not display) 00 - FF 00 00 00

No.

Item name

Variable

range

Setting value

PAL SECAM NTSC

Item

D164 (Not display) 00 - FF 00 00 00

D165 (Not display) 00 - FF 00 00 00

D166 (Not display) 00 - FF 00 00 00

D167 (Not display) 00 - FF 00 00 00

D168 (Not display) 00 - FF 00 00 00

D169 (Not display) 00 - FF 00 00 00

D170 (Not display) 00 - FF 00 00 00

D171 (Not display) 00 - FF 00 00 00

D172 (Not display) 00 - FF 00 00 00

D173 (Not display) 00 - FF 00 00 00

D174 (Not display) 00 - FF 00 00 00

D175 (Not display) 00 - FF 00 00 00

D176 (Not display) 00 - FF 00 00 00

D177 (Not display) 00 - FF 00 00 00

D178 (Not display) 00 - FF 00 00 00

D179 (Not display) 00 - FF 00 00 00

D180 (Not display) 00 - FF 00 00 00

D181 (Not display) 00 - FF 00 00 00

D182 (Not display) 00 - FF 00 00 00

D183 (Not display) 00 - FF 00 00 00

D184 (Not display) 00 - FF 00 00 00

D185 (Not display) 00 - FF 00 00 00

D186 (Not display) 00 - FF 00 00 00

D187 (Not display) 00 - FF 00 00 00

4.6.5 MAIN CPU SYETEM SETTING (*Fixed values)

Item

Z001 (Not display) 00 - FF 00 00 00

Z002 (Not display) 00 - FF 00 00 00

Z003 (Not display) 00 - FF 00 00 00

Z004 (Not display) 00 - FF 00 00 00

Z005 (Not display) 00 - FF 00 00 00

Z006 (Not display) 00 - FF 00 00 00

Z007 (Not display) 00 - FF 00 00 00

Z008 (Not display) 00 - FF 00 00 00

Z009 (Not display) 00 - FF 00 00 00

Z010 (Not display) 00 - FF 00 00 00

No.

Item name

Variable

range

Variable

range

Setting value

PAL SECAM NTSC

Setting value

PAL SECAM NTSC

1-20 (No.YA208)

4.7 ADJUSTMENT PROCEDURE

4.7.1 VIDEO CIRCUIT

Item

625i A-D OFFSET

Measuring

instrument

Remote control unit

Test point Adjustment part Description

Signal generator

Disappears the color at both ends.

1125i (50Hz) BRIGHTNESS

Remote control unit

Signal generator

Set the 0% black part to be brightest.

1125i (50Hz) A-D OFFSET

Remote control unit

Signal generator

Minimize the red and blue noises in the upper half of the screen.

[1.ADJUST] S001: PREPARE (Adjustment setting mode change)

S008: 5i CB OF(625i cb offset) S009: 5i CR OF(625i cr offset)

S030: R DRIVE(Red drive) S031: G DRIVE(Green drive) S032: B DRIVE(Blue drive)

[1.ADJUST] S001: PREPARE (Adjustment setting mode change)

S012: HD BL(1125i brightness)

S030: R DRIVE(Red drive) S031: G DRIVE(Green drive) S032: B DRIVE(Blue drive)

[1.ADJUST] S001: PREPARE (Adjustment setting mode change)

S013: HD CB OF(1125i cb offset) S014: HD CR OF(1125i cr offset)

S030: R DRIVE(Red drive) S031: G DRIVE(Green drive) S032: B DRIVE(Blue drive)

(1) Receive a 625i component ramp pattern signal. (2) Set "PICTURE MODE" to STANDARD. (3) Set "ZOOM" to FULL. (4) Set "WHITE BALANCE" to MID. (5) Select "1.ADJUST" from the SERVICE MODE. (6) Set < S030 > (R DRIVE), < S031> (G DRIVE)

and < S032 > (B DRIVE) to "133".

(7) Set < S001 >(adjustment setting mode change)

to set "8" and it change to the 625i A-D offset adjustment setting mode.

(8) Adjust < S008 > (625i Cb offset) and < S009 >

(625i Cr offset) to lose the gap (red line, green line and blue line) which appears at both ends of a white part at the centre of the screen.

(9) Set < S001 > to set "0" and it change to the

normal mode.

(10) Press the [MUTING] key to memoirze the set

value.

(1) Receive a 1125i (50Hz) gray scale pattern signal. (2) Set "PICTURE MODE" to STANDARD. (3) Set "ZOOM" to FULL. (4) Set "WHITE BALANCE" to MID. (5) Select "1.ADJUST" from the SERVICE MODE. (6) Set < S030 > (R DRIVE), < S031> (G DRIVE)

and < S032 > (B DRIVE) to "133".

(7) Set < S001 > (adjustment setting mode change)

to set the values "12" and it change to the 1125i black level adjustment setting mode.

(8) Adjust < S012 > (1125i brightness) to set the

0% black part in the upper half of the screen to be brightest.

(9) Set < S001 > to set "0" and it change to the

normal mode.

(10) Press the [MUTING] key to memoirze the set

value.

(1) Receive a 1125i (50Hz) 30% all white pattern

signal. (2) Set "PICTURE MODE" to STANDARD. (3) Set "ZOOM" to FULL. (4) Set "WHITE BALANCE" to MID. (5) Select "1.ADJUST" from the SERVICE MODE. (6) Set < S030 > (R DRIVE), < S031> (G DRIVE)

and < S032 > (B DRIVE) to "133". (7) Set < S001 > (adjustment setting mode change)

to set "13" and it change to the 1125i A-D offset

adjustment setting mode. (8) Adjust < S013 > (1125i Cb offset) to minimize

the blue noise in the upper half of the screen. (9) Adjust < S014 > (1125i Cr offset) to minimize

the blue noise in the upper half of the screen.

(10) Set < S001 > to set "0" and it change to the

normal mode.

(11) Press the [MUTING] key to memoirze the set

value.

(No.YA208)1-21

Item

SUB SCREEN A-D OFFSET

Set the 0% block part to be brightest.

VIDEO-1

WHITE BALANCE (HIGHLIGHT)

Measuring

instrument

Remote control unit

Signal generator

TV(RF)

<30% all white>

Remote control unit

Signal generator

Test point Adjustment part Description

[1.ADJUST] S001: PREPARE (Adjustment setting mode change)

(1) Set "PICTURE MODE" to STANDARD. (2) Set "ZOOM" to FULL. (3) Set "WHITE BALANCE" to MID.

(4) Set "MULTI PICTURE" to 2 pictures. S016: RT CB OF (Sub screen cb offset) S017: RT CR OF (Sub screen cr offset)

(5) Receive a PAL 30% all white pattern signal on

the Right screen. At the same time, set the Left

screen in VIDEO-1 mode (No signal). (6) Select "1.ADJUST" from the SERVICE MODE. (7) Set < S030 > (R DRIVE), < S031> (G DRIVE)

S030: R DRIVE(Red drive) S031: G DRIVE(Green drive) S032: B DRIVE(Blue drive)

and < S032 > (B DRIVE) to "133". (8) Set < S001 > (adjustment setting mode change)

to set "17" and it change to the sub screen A-D

offset adjustment setting mode. (9) Adjust < S016 > (Sub screen cb offset) to

minimize the blue noise in the upper half of the

screen.

If you select an adjustment item < S016 >,

then the screen automatically turn to twin

pictures mode.

(10) Set < S017 > (Sub screen cr offset) to minimize

the red noise in the upper half of the screen.

(11) Readjust < S016 > and < S017 > to set the

upper half of the screen to be the blackest. (See

Fig.9)

(12) Set < S001 > to set "0" and it change to the

normal mode.

(13) Press the [MUTING] key to memoirze the set

value.

[1.ADJUST] S030: R DRIVE (Red drive) S031: G DRIVE (Green drive) S032: B DRIVE (Blue drive)

(1) Receive a PAL 75% all white signal. (2) Set "PICTURE MODE" to STANDARD. (3) Set "ZOOM" to FULL. (4) Set "WHITE BALANCE" to MID. (5) Select "1.ADJUST" from the SERVICE MODE. (6) Adjust to keep one of < S030 > (Red drive),

< S031 > (Green drive) or < S032 > (Blue drive)

unchanged, then lower the other two so that the

all-white screen is equally white throughout.

NOTE:

Set one or more of < S030 >, < S031 >, and

< S032 > to "85". (7) Check that white balance is properly tracked

from low light to high light. If the white balance

tracking is deviated, adjust to correct it. (8) Press the [MUTING] key to memoirze the set

value.

1-22 (No.YA208)

SECTION 5

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

LOB OK FAN OK SYNC M:OK S:OK HD:NG TIM OK MSM OK DIGI 0000 MEM OK AVSW OK YC OK AIO OK TUN OK GCR NG 1 IP OK RGB OK 8 DVI OK HDMI OK

FAN OK ALM OK TMP OK ATP OK ASH OK

PNL OK MEM OK TMP OK AIO OK

TROUBLESHOOTING

5.1 SELF CHECK FEATURE

5.1.1 OUTLINE

This unit comes with the "Self check" feature, which checks the operational state of the circuit and displays/saves it during failure.Diagnosis is performed when power is turned on, and information input to the main microcomputer is monitored at all time.Diagnosis is displayed in 2 ways via screen display and LED flashes. Failure detection is based on input state of I

C bus and

the various control lines connected to the main microcomputer.

5.1.2 HOW TO ENTER THE SELF CHECK MODE

Before entering the SERVICE MODE, confirm that the setting of PIP/TV/ DVD switch is at the "TV" side. If the switches have not been properly set, you cannot enter the SERVICE MODE.

(1) Press [DISPLAY] key and [MUTING] key simultaneously,

then enter the SERVICE MODE. (2) Press the [2] key SELF CHECK MODE. (3) Press the [ZOOM] key to enter Page 2 of the SELF CHECK

MODE.

*Use the [CINEMA] key to toggle between Page 1 and

Page 2.

NOTE:

When a number key other than the [1] to [3] key is pressed in the SERVICE MODE screen, the other relevant screen may be displayed. This is not used in the adjustment procedure. Press the [MENU] key to return to the MAIN MENU SCREEN.

5.1.3 HOW TO EXIT THE SELF CHECK MODE To Save Failure History:

Turn off the power by unplugging the AC power cord plug when in the Self check display mode.

To Clear (Reset) Failure History:

Turn off the power by pressing the [POWER] key on the remote control unit when in the Self check display mode.

5.1.4 FAILURE HISTORY

Failure history can be counted up to 9 times for each item. When the number exceeds 9, display will remain as 9. Failure history will be stored in the memory unless it has been deleted.

NOTE:

Only SYNC (with/without sync signals) will be neither counted nor stored.

5.1.5 POINTS TO NOTE WHEN USING THE SELF CHECK FEATURE

In addition to circuit failures (abnormal operation), the following cases may also be iagnosed as "Abnormal" and displayed and counted as "NG".

(1) Temporary defective transmissions across circuits due to

pulse interruptions

(2) Misalignment in the on/off timing of power for I

C bus

(VCC) when turning on/off the main power. Diagnosis may be impeded if a large number of items are displayed as "NG". As such, start Self check check only after 3 seconds in the case of receivers and 5 seconds in the case of panels upon turning on the power. If recurrences are expected, ensure to clear (reset) the failure history and record the new diagnosis reults.

SERVICE MODE SCREEN

SERVICE MENU

1.ADJUST

2.SELF_CHK

3.I2C STOP

SELF CHECK MODE SCREEN (Page 1)

LOB OK FAN OK SYNC M:OK S:OK HD:NG TIM OK MSM OK DIGI 0000 MEM OK AVSW OK YC OK AIO OK TUN OK GCR NG 1 IP OK RGB OK 8 DVI OK HDMI OK

Item

CHECK Normality=OK Abnormality=NG

SELF CHECK MODE SCREEN (Page 2)

FAN OK ALM OK TMP OK ATP OK ASH OK

PNL OK MEM OK TMP OK AIO OK

Item

* As "SYNC" is not counted, the number of failures not displayed.

CHECK Normality=OK Abnormality=NG

Fig.1

(No.YA208)1-23

5.1.6 DETAILS

Self check is performed for the following items:

< Page 1 of screen >

Detection item Display Detection content

Low bias line short protection

LOB Confirmation of operation of the low bais

(2.5V / 3.3V / 5V / 9V) protection circuit.

Q9822 [REGULATOR PWB]

Diagnosis

signal (line)

Detection timing

LB_PRO Detection starts 3 seconds after the

power is turned on. If error continues between 400ms the power is turned off.

Abnormal rise of temperature in audio circuit

FAN Confirmation of the temperature of

audio circuit.

TH6661 [ANALOG SIGNAL PWB]

SDA Detection starts 3 seconds after the

power is turned on.

If the temperture of 90°C is detected for

3 seconds the power is turned off.

Presence of sync signal SYNC Confirmation of presence of video

sync signal.

SDA Confirmation of presence of sync signal

in video signal. M : Main sync signal S : Sub sync signal HD : Component sync signal

IC201 [ANALOG SIGNAL PWB]

AC power input TIM Not used. --- ---

Main CPU

MSM Not used. --- ---

communication

Digital tuner DIGI Not used. --- ---

Main memory MEM Confirmation of reply of ACK signal

which uses I

C communication.

IC7602 [DIGITAL SIGNAL PWB]

AV select switch AVSW Same as above.

SDA If it checks whenever I2C communication

is performed and no reply of ACK signal

an error will be counted.

SDA Same as above.

IC301, IC501 [ANALOG SIGNAL PWB]

3 dimensions YC

YC Not used. --- ---

separator

Multi sound process AIO Not used. --- ---

RF tuner TUN Confirmation of reply of ACK signal

which uses I

C communication.

TU3001 [RECEIVER PWB]

SDA If it checks whenever I2C communication

is performed and no reply of ACK signal

an error will be counted.

Ghost reduction GCR Not used. --- ---

DIST process IP Confirmation of reply of ACK signal

which uses I

C communication.

IC3001 [DIGITAL SIGNAL PWB]

RGB process RGB Confirmation of reply of ACK signal

which uses I

C communication.

IC3001 [DIGITAL SIGNAL PWB]

DVI (Digital communication)

DVI Not used. --- ---

SDA If it checks whenever I

is performed and no reply of ACK signal

an error will be counted.

SDA If it checks whenever I

is performed and no reply of ACK signal

an error will be counted.

Digital input HDMI Not used. --- ---

C communication

1-24 (No.YA208)

< Page 2 of screen >

Detection item Display Detection content

Diagnosis

signal (line)

Detection timing

Fan lock FAN Not used. --- ---

Abnormal of operation of

ALM Not used. --- ---

PANEL

Abnormal rise

TMP Not used. --- ---

oftemperature in PANEL

Abnormal rise of

ATP Not used. --- --temperature in audio circuit

Short circuit detection of

ASH Not used. --- --audio circuit

Panel communication PNL Not used. --- ---

Sub memory MEM Not used. --- ---

Temp. sensor TMP Not used. --- ---

Audio control AIO Confirmation of reply of ACK signal

which uses I

C communication.

IC6521 [ANALOG SIGNAL PWB]

SDA If it checks whenever I

is performed and no reply of ACK signal an error will be counted.

5.1.7 METHOD OF DISPLAY WHEN A RASTER IS NOT OUTPUT

In the state where a raster is not output by breakdown of the set, an error is displayed by blink of the POWER LED.

Type of error POWER LED flash cycle

Low bias line short protection Low luminance blue turnig on and off at 1 second intervals.

Abnormal rise of temperature in audio circuit High luminance blue turnig on and off at 0.1 second intervals.

C communication

< Explanation of operation >

If error is detected, the power is turned off. Shortly after a power is turned off, POWER LED will be blinked. Power cannot be turned on until the power cord takes out and inserts, after a power is turned off.

(No.YA208)1-25

Victor Company of Japan, Limited AV & MULTIMEDIA COMPANY VIDEO DISPLAY CATEGORY 12, 3-chome, Moriya-cho, kanagawa-ku, Yokohama, kanagawa-prefecture, 221-8528, Japan

(No.YA208)

Printed in Japan

VPT

SERVICE MANUAL

WIDE LCD PANEL TELEVISION

YA208C20054

BASIC CHASSIS

LT-Z26SX4B,

LT-Z26SX4B LT-Z26SX4B LT-Z26SX4S LT-Z26SX4B

Supplementary

Please be informed that this service manual contains the related matters following the parts replacement in the LCD PANEL UNIT. For details other than those described in this manual, please refer to the LT-Z26SX4B, LT-Z26SX4B/A, LTZ26SX4B/S and LT-Z26SX4S/S service manual (No.YA208, 2004/12) LT-Z26SX4B/C service manual (No.YA208B, 2005/1).

SECTION 1

/A, /S,

/S,

PRECAUTION

Please refer to "LT-Z26SX4B, LT-Z26SX4B/A, LT-Z26SX4B/S and LT-Z26SX4S/S (No.YA208)" about this section.

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

Please refer to "LT-Z26SX4B, LT-Z26SX4B/A, LT-Z26SX4B/S and LT-Z26SX4S/S (No.YA208)" about this section.

No.YA208C

2005/4

SECTION 3

DISASSEMBLY

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.

• During the procedure, place a mirror mat etc. under the LCD UNIT and be careful not to damage the PANEL.

• Make sure that there is no bent or stain on the connectors before inserting, and firmly insert the connectors.

3.1 DISASSEMBLY PROCEDURE

3.1.1 CAUTION ON REMOVING THE LCD PANEL UNIT

The LCD PANEL is fixed to the FRONT PANEL (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.

LCD PANEL UNIT

Double-side adhesive tapes

FRONT PANEL

3.1.2 REMOVING THE CONTROL PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

• Remove the LCD PANEL UNIT. (1) Remove the 4 screws [A], then remove the CONTROL

PWB COVER.

(2) Remove the 2 screws [B], then remove the CONTROL

PWB.

CAUTION:

Carry out the procedure with extra care as the FERRITE CORE is affixed with double-side adhesive tapes and it may break if extra force is applied.

3.1.3 REMOVING THE INVERTER PWB (Fig.1)

• Remove the STAND.

• Remove the REAR COVER.

• Remove the LCD PANEL UNIT. (1) Remove the 6 screws [C], then remove the INVERTER

PWB COVER.

(2) Remove the 3 screws [D], then remove the INVERTER

PWB.

(3) Remove the 8 screws [E], then remove the INVERTER

PWB COVER.

(4) Remove the 3 screws [F], then remove the INVERTER

COLD PWB.

3.1.4 REMOVING THE BACK LIGHT UINT (Fig.1)

CAUTION:

When replacing the BACK LIGHT UINT, be careful to prevent dust attachment to the UNIT. If dust particles attached to the UNIT, it becomes the cause of uneven brightness.

• Remove the STAND.

• Remove the REAR COVER.

• Remove the LCD PANEL UNIT.

• Remove the CONTROL PWB.

• Remove the INVERTER PWB.

• Remove the INVERTER COLD PWB. (1) Remove the 14 screws [G], then remove the TOP PANEL

FRAME.

(2) Remove the 4 screws [H], then remove the LCD PANEL.

CAUTION:

When removing the LCD PANEL, be careful not to give stress to the FPC which connects the PWB and the LCD PANEL.

CAUTION ON EXCHAGING THE BACK LIGHT UINT

• If the screws that are not specified in this section are

removed, the LCD PANEL will be removed and it cannot be reassembled.

1-2 (No.YA208C)

INVERTER PWB COVER

INVERTER PWB

FERRITE CORE

CONTROL PWB COVER

CONTROL PWB

INVERTER COLD PWB

FRONT

LCD PANEL UNIT

TOP PANEL FRAME

FRONT

LCD PANEL

Fig.1

BACK LIGHT UNIT

(No.YA208C)1-3

SECTION 4

ADJUSTMENT

Please refer to "LT-Z26SX4B, LT-Z26SX4B/A, LT-Z26SX4B/S and LT-Z26SX4S/S (No.YA208)" about this section.

SECTION 5

TROUBLESHOOTING

Please refer to "LT-Z26SX4B, LT-Z26SX4B/A, LT-Z26SX4B/S and LT-Z26SX4S/S (No.YA208)" about this section.

1-4 (No.YA208C)

+ 136 hidden pages