Akai LCT42Z6TM Service Manual

AKAI

SERVICE MANUAL

Model: LCT42Z6TM

1. Safety Instructions………………...………………………………………………….1~2

2. Trouble Shooting manual of LCD…………………………………………………….3~4

3. Product Specification………………………………………………………………….5~7

4. Block Diagram….…………………………………………………………………….8~9

5. Circuit diagram……………………………………………………………………….10~17

6. Basic Operation & Circuit Description………………………………………………18~20

7. Main IC Information…………………………………………………………………21~39

8. Panel Information……………………………………………………………………40~68

9. Explored View………………………………………………………………………69

10. Spare Pare List………………………………………………………………………70~72

11. Software Upgrade……………………………………………………………………73~75

This manual is the latest at the time of printing, and does not
include the modification which may be made after the printing,
by the constant improvement of product.

I. Safety Instructions

1／75

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

The lightning flash with arrowhead symbol,
within an equilateral triangle, is intended to alert
the user to the presence of uninsulated “ dangerous
voltage” within the product’ s enclosure that may
be of sufficient magnitude to constitute a risk of
electric shock to persons.

CAUTION: TO REDUCE THE RISK OF ELECTRIC
SHOCK, DO NOT REMOVE COVER (OR BACK). NO
USER-SERVICEABLE PARTS INSIDE. REFER
SERVICING TO QUALIFIED SERVICE PERSONNEL
ONLY.

PRECAUTIONS DURING SERVICING

1. In addition to safety, other parts and assemblies are
specified for conformance with such regulations as
those applying to spurious radiation. These must
also be replaced only with specified replacements.
Examples: RF converters, tuner units, antenna
selection switches, RF cables, noise-blocking
capacitors, noise-blocking filters, etc.

2. Use specified internal Wiring. Note especially:

1) Wires covered with PVC tubing

2) Double insulated wires

3) High voltage leads

3. Use specified insulating materials for hazardous
live parts. Note especially:

1) Insulating Tape

2) PVC tubing

3) Spacers (insulating barriers)

4) Insulating sheets for transistors

5) Plastic screws for fixing micro switches

4. When replacing AC primary side components
(transformers, power cords, noise blocking
capacitors, etc.), wrap ends of wires securely about
the terminals before soldering.

The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and maintenance
(s erv ici ng) in str uct io ns in the li ter atu re
accompanying the appliance.

SAFETY INSTRUCTION

The service should not be attempted by anyone
unfamiliar with the necessary instructions on this
monitor. The following are the necessary instructions
to be observed before servicing.

1. An isolation transformer should be connected in the
power line between the receiver and the AC line
when a service is performed on the primary of the
converter transformer of the set.

2. Comply with all caution and safety related provided
on the back of the cabinet, inside the cabinet, on the
chassis or picture tube.

3. To avoid a shock hazard, always discharge the
picture tube's anode to the chassis ground before
removing the anode cap.

5. Make sure that wires do not contact heat generating
parts (heat sinks, oxide metal film resistors, fusible
resistors, etc.)

6. Check if replaced wires do not contact sharply edged
or pointed parts.

7. Make sure that foreign objects (screws, solder
droplets, etc.) do not remain inside the set.

MAKE YOUR CONTRIBUTION TO PROTECT THE
ENVIRONMENT

Used batteries with the ISO symbol
for recycling as well as small
accumulators (rechargeable batteries), mini-batteries
(cells) and starter batteries should not be thrown
into the garbage can.
Please leave them at an appropriate depot.

- 2 -

4. Completely discharge the high potential voltage of the

2／75

picture tube before handling. The picture tube is a
vacuum and if broken, the glass will explode.

5. When replacing a MAIN PCB in the cabinet, always
be certain that all protective are installed properly
such as control knobs, adjustment covers or shields,
barriers, isolation resistor networks etc.

6. When servicing is required, observe the original lead
dressing. Extra precaution should be given to assure
correct lead dressing in the high voltage area.

7. Keep wires away from high voltage or high tempera
ture components.

8. Before returning the set to the customer, always
perform an AC leakage current check on the exposed
metallic parts of the cabinet, such as antennas,
terminals, screwheads, metal overlay, control shafts,
etc., to be sure the set is safe to operate without
danger of electrical shock. Plug the AC line cord
directly to the AC outlet (do not use a line isolation
transformer during this check). Use an AC voltmeter
having 5K ohms volt sensitivity or more in the
following manner.
Connect a 1.5K ohm 10 watt resistor paralleled by a

0.15µF AC type capacitor, between a good earth
ground (water pipe, conductor etc.,) and the exposed
metallic parts, one at a time.
Measure the AC voltage across the combination of
the 1.5K ohm resistor and 0.15 uF capacitor. Reverse
the AC plug at the AC outlet and repeat the AC
voltage measurements for each exposed metallic
part.
The measured voltage must not exceed 0.3V RMS.
This corresponds to 0.5mA AC. Any value exceeding
this limit constitutes a potential shock hazard and
must be corrected immediately.
The resistance measurement should be done
between accessible exposed metal parts and power
cord plug prongs with the power switch "ON". The
resistance should be more than 6M ohms.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this
monitor have special safety-related characteristics.
These characteristics are offer passed unnoticed by
visual spection and the protection afforded by them
cannot necessarily be obtained by using replacement
components rates for a higher voltage, wattage, etc.
The replacement parts which have these special
safety characteristics are identified by marks on
the schematic diagram and on the parts list.
Before replacing any of these components, read the
parts list in this manual carefully. The use of
substitute replacement parts which do not have the
same safety characteristics as specified in the parts
list may create shock, fire, X-RAY RADIATION or
other hazards.

Good earth ground
such as the water
pipe, c o ndu c t or ,
etc.

AC Leakage Current Check

AC VOLTMETER

Place this probe
on eac h e x­posed me t al li c
part

No image or badly distorted image with horizontal and/or vertical lines static lines.

Symptom may have four boxes

Procedure Instructions

in each of the corners of the screen.

There are 5 capacitors on the main PCB that have been identified as the primary

cause of this symptom.

C-280 C-301, C-302, C-320 and C-323/ surface

warranty claims, list work as RPRE on the claim and list the cost of the caps to the
"shipping" section of the claim for proper processing.

Replace the capacitors in location #'s on the Main PCB -

mounted 100UF 35 VOLTS. For

3／75

1.Do not power on .

1.1 Please check AC cable if connect to AC plug.

Is true the connector don’t connect to AC plug. Please connect it.

1.2 Please check AC cable if connect to AC power.

Is true the AC cable don’t connect to AC power. Please connect it.

1.3 Please check power board of fuse if broken.

If the F1 fuse is broken, Please pull out the AC cable from AC power. Please check AC L

power and AC N ground by multimeter, The read number is infinite, the fuse is broke. then

look up power board if not burn out place. Is true it. Please change power board or be changed

power board.

2. The power on switch of green extinguish.

2.1 The power of led(indicator light) is red light, To touch power on key when indicator light

wink.

Is true that the power DC output have somewhere short circuit.

3.The power is normal work ,but don’t backlight.

3.1 The indicator light work normal (green light ).

Please refer to attached sheet A circuit diagram.

3.2 Please check backlight of connector if not it direction is wrong or the connector of wire

compositor direction is wrong.

3.3 To check connector panel of voltage is +24v. It’s true. Then to check of the first pin if it

4／75

have +5V voltage, It’s true, than to check power board of +24v voltage, It’s true. The

panel of backlight board is fail. The change panel of backlight board.

Please refer to attached sheet B Panel of datasheet.

4.The screen don’t have picture But have backlight.

4.1 To check to panel of voltage , to check Main Board IC N031 the 5 pin of voltage is +12v.

If not, check the +12v power.

Please refer to attached sheet A circuit diagram.

5.The remote control don’t be control.

5.1 The check batteries of remote control if it run out of .

5.2 To check main board of connecter X014 of wire connect fastness and the connecter of

wire open.

Please refer to attached sheet A circuit diagram.

6.The sound don’t output.

6.1 To check main board +24v voltage of connector X032, It’s true not +24v voltage. Then

to to check power main +24v fail .

Please refer to attached sheet A circuit diagram.

Product Specification

Product Model: LCT42Z6TM

Screen Size: 42” diagonal

Screen Area: 930.24mm(H) x 531.26mm(V)

Aspect Ratio: 16:9

External Size:

1067.3mm(W) x 781.2mm(H) x 275.0mm(D) (with Stand)

1

067.3mm(W) x 732.3mm(H) x 117.0mm(D) (w/o Stand)

Net Weight:

27.5kg (with Stand)

Resolution: 1920 (H) x 1080 (V) pixels (Each pixel has R/G/B 3

color cells)

Pixel Dot Pitch: 0.4845mm(H) x 0.4845mm(V)

Color: 16.7 millions of colors (R/G/B each 256 scales)

Gray Scale: 256 (R/G/B each 8-bit)

Brightness(Peak Value): 500cd/m

2

Contrast(Dark Room): 800:1

Color System: PAL, NTSC

Sound Effect: Acoustic Cinema Enhancement

Power Supply: AC 120V, 60 Hz

Power Consumption: 300W

Input/Output Terminal: HDMI (Ver1.1) connector x 1

VGA ( D-Sub 15 Pin ) x 1

Component Video - YPbPr x 2 RCA Terminals

Video Input RCA Terminals x 1

S-Video Input Mini Din 4 Pin Terminal x 1

1 set of Stereo Audio Output Terminals (RCA, L&R)

Stereo, Audio x 5

5／75

Support the Signal Mode

A. D-Sub Mode (VGA)

B. HDTV Mode (YPbPr)

Resolution

Horizontal
Frequency

(KHz)

Vertical

Frequency

(Hz)

640 x 480 31.50 60.00

800 x 600

35.16 56.25

37.90 60.32

1024 x 768 48.40 60.00

1280 x 1024 64.00 60.01

Resolution

Horizontal

Frequency

(KHz)

Vertical

Frequency

(Hz)

480i 15.734 59.94

480p(720x480) 31.468 59.94

720p(1280x720)

37.50 50.00

45.00 60.00

1080i(1920x1080) 33.75 60.00

1080P 68.00 60.00

- When the signal received by the Display exceeds the allowed range, a warning
message shall appear on the screen.

- You can confirm the input signal format from the on-screen.

Resolution

Horizontal

Frequency

(KHz)

Vertical

Frequency

(Hz)

480p 31.468 59.94

720p

37.50 50.00

45.00 60.00

1080i

28.125 50.00

33.75 60.00

1080P 68.00 60.00

C. HDMI Mode

6／75

Remote Control

󱯎 Standby( ): Press this button to turn off
to standby and turn on from standby.
󱯐 Mute( ): Press this button to quiet the
sound system. Press again to reactivate
the sound system.
󱯒 Number buttons: Use these buttons
to enter the password.
󱯔 Source: Press this button and use

▲ / ▼ button to select the signal sources.

VIDEO, S-VIDEO,

YPbPr 1, YPbPr 2,

VGA or HDMI

.

󱯖

Sleep: Press this button to

select

the
sleep time, such as “15 Min, 30 Min,
45Min, 60 Min, 90 Min,

120 Min or Off”.

󱯘 VOL +/- : Press these buttons to

increase

or decrease the volume

.

󱯚 P. Mode : Press the button to select
different

picture effect, such as “Nature,

Bright,

User or Soft”.

󱯜 System: Press this button to select the

color system, such as “PAL, NTSC or
AUTO”.

(Only for VIDEO and S-VIDEO)

󱯞Enter : Press to enter or confirm.
◄ / ► : They are used as ◄ / ► buttons
in the OSD Menu screen. ► also has
enter function.
▲ / ▼ : They are used as ▲ / ▼ buttons
in the OSD Menu screen.

󱯠 Exit: Press this button to exit the OSD Menu.

󱯎

󱯒

󱯖

󱯘

󱯞

󱯠

󱯢
󱯣
󱯦

󱯐

󱯔

󱯚
󱯜

󱯡

󱯤
󱯥
󱯧

󱯡

Menu: Press this button to pop up the OSD Menu
and press it again to exit the OSD Menu.

󱯢 V-Chip: Press this button to enter the V-Chip Function. (Only for VIDEO and
S-VIDEO)

󱯣 Freeze: Press this button to hold on the screen. Press again to normal.
󱯤 C/C: Press this button to change the CC mode. (Only for VIDEO and S-VIDEO)
󱯥 Display: Press the button to display the source information.
󱯦 S. Mode: Press the button to select different sound effect, such as “Normal,

News, Music or User”.
󱯧 P. Size: Press this button, the picture will change according

to

Full, Zoom,

Letter Box or 4:3. (Inactive for VGA)

7／75

HY5DU281622FT

8／75

DDR128M

PS25LV010A
flash

S-Video
Audio

Video
Audio

YPbPr1

YPbPr2

YPbPr1
Audio

YPbPr2
Audio

HDMI

VGA

DVI/VGA

S-Video

Video

Switch
4052

Switch
PI5V330

Audio

MST9U89AL

LVDS

Audio

Panel

Operation
Amplifier
4558R

Operation
Amplifier
4558R

Audio
Amplifier
R251502NP

Speaker

Audio
Out

2

E PROM
24C32

Parts position

9／75

Key Pad

Speaker

Power Board

Speaker

Main Board IR Board

10／75

11／75

12／75

13／75

14／75

15／75

16／75

17／75

Basic Operations & Circuit Description

18／75

MODULE

There are 1 pcs panel and 5 pcs PCB including 3 pcs Extension PCB, 1 pcs Timming controller board and 1 pcs Back Light board

in the Module.

SET

There are 3 pcs PCBs including 1 pcs, 1 pcs keypad board, 1 pcs Remote Control Receiver board, 1 pcs Main(Video)board.

PCB funtion

19／75

1. Power :

(1). Input voltage: AC 120V, 60Hz.

(2). To provide power for PCBs.

2. Main board : To converter, S signals, AV signals, Y Pb/Cb Pr/Cr signals, DVI/HDMI signals and

D-SUB signals to digital ones and to

dealing with the digital signal for output to panel.

PCB failure analysis

20／75

1. POWER : NO picture, no power output.

2. Back Light : a. No picture.

b. Flash on screen.

c. Darker picture with signals.

Main IC Specifications

21／75

- HDTV Controller with Video Decoder & 10-bit Dual LVDS Transmitter

MST9U89AL

22／75

HDTV Controller with Video Decoder & 10-bit Dual LVDS Transmitter

Preliminary Data Sheet Version 0.5

FEATURES

Ÿ LCD TV controller with PIP/POP display functions
Ÿ Input supports up to SXGA & 1080P
Ÿ Panel supports up to full HD panels (1920x1080)
Ÿ TV decoder with 3-D comb filter
Ÿ Multi-Standard TV sound demodulator and

decoder

Ÿ 10-bit triple-ADC for TV and RGB/YPbPr
Ÿ 10-bit video data processing
Ÿ Integrated DVI/HDCP/HDMI compliant receiver
Ÿ High-quality dual scaling engines & 3-D video

de-interlacers

Ÿ Full function PIP/PBP/POP

Note

Ÿ MStarACE-3 picture/color processing engine
Ÿ Embedded On-screen display controller (OSD)

engine

Ÿ Built-in MCU supports PWM & GPIO
Ÿ Built-in dual-link 8/10-bit LVDS transmitter
Ÿ 5 Volt tolerant inputs
Ÿ Low EMI and power saving features
Ÿ 256-pin LQFP

n NTSC/PAL/SECAM Video Decoder

Ÿ Supports NTSC M, NTSC-J, NTSC-4.43, PAL

(B,D,G,H,M,N,I,Nc), and SECAM

Ÿ Automatic TV standard detection
Ÿ Motion adaptive 3-D comb filter for NTSC/PAL
Ÿ 8 configurable CVBS & Y/C S-video inputs
Ÿ Supports Closed-caption and V-chip
Ÿ Macrovision detection
Ÿ CVBS video output

n Multi-Standard TV Sound Decoder

Ÿ Supports BTSC/A2/EIA-J demodulation and

decoding

Ÿ FM stereo & SAP demodulation
Ÿ L/Rx4, mono, and SIF audio input
Ÿ L/R loudspeaker and line outputs
Ÿ Supports sub-woofer output
Ÿ Built-in audio output DAC’s
Ÿ Audio processing for loudspeaker channel,

including volume, balance, mute, tone, EQ,
and virtual stereo/surround

n Digital Audio Interface

Ÿ I2S digital audio input & output
Ÿ S/PDIF digital audio input & output
Ÿ HDMI audio channel processing capability
Ÿ Programmable delay for audio/video

synchronization

n Analog RGB Compliant Input Ports

Ÿ Three analog ports support up to 150MHz
Ÿ Supports PC RGB input up to SXGA@75Hz
Ÿ Fast blanking and function selection switch

support full SCART functions

Ÿ Supports HDTV RGB/YPbPr/YCbCr up to 1080P
Ÿ Supports Composite Sync and SOG

(Sync-on-Green) separator

Ÿ Automatic color calibration

n DVI/HDCP/HDMI Compliant Input Port

Ÿ Operates up to 150 MHz (up to SXGA @75Hz)
Ÿ Single link on-chip DVI 1.0 compliant receiver
Ÿ High-bandwidth Digital Content Protection

(HDCP) 1.1 compliant receiver

Ÿ High Definition Multimedia Interface (HDMI)

1.2 compliant receiver

Ÿ Long-cable tolerant robust receiving
Ÿ Support HDTV up to 1080P

n Auto-Configuration/Auto-Detection

Ÿ Auto input signal format and mode detection
Ÿ Auto-tuning function including phasing,

positioning, offset, gain, and jitter detection

Ÿ Sync Detection for H/V Sync

n Digital Video Input Port

Ÿ One 4:2:2 ITU-R BT.656 8/10-bit digital video

input port

Ÿ One 4:2:2 ITU-R BT.601 16-bit digital video

input port

n High-Performance Scaling Engine

Ÿ Fully Programmable shrink/zoom capabilities
Ÿ Nonlinear video scaling supports various

modes including Panorama

Ÿ Supports keystone correction for projectors

n Video Processing & Conversion

Ÿ 3-D motion adaptive video de-interlacers
Ÿ Edge-oriented adaptive algorithm for smooth

low-angle edges

- 1 - 8/21/2006

Copyright © 2006 MStar Semiconductor, Inc. All rights reserved.