Hitachi Alpha L42A404 User manual

CAUTION: Be sure to read this manual before servicing. To ensure safety from fire, electric shock, injury,
harmful radiation and materials, various measures are provided in this LCD TV. Be sure to read cautionary items
described in the manual before servicing. These servicing instructions are for use by qualified service personnel
only. To reduce the risk of electric shock, do not perform any servicing other than that described in the operating
instructions unless you are qualified to do so.
SERVICE WARNING
1. Replacement work should be started after the Panel Module and the AC/DC Power supply have become
sufficiently cool.
2. Special care should be taken when working near the display area in order not to damage its surface.
3. The Panel Module should not be touched with bare hands in order to protect its surface from blemishes and
damage.
4. It is recommended that you use clean soft gloves during the replacement work in order to protect not only the
display area of the Panel Module but also yourself.
L42A404 2010-10 v1
L42A404
HITACHI TV
HITACHI
Schematic Diagram……...………………………...………14
Connection Diagram……..……….………….……..……..29
Main Parts View.……..……….………………....…….......30
PCB Layout…………..………………………....……….....31
Exploded View…………..……………..……….................37
Parts List………...…..……..............................................40
Features…….……….…........................................……......3
Dimensions………..……..……………………………………4
General Specification...................................…………........5
Firmware Upgrade.………….………….……………..........6
Adjustment…….…………..………..….…………….…….....7
Troubleshooting…………...……………………...…..….......8
Block Diagram.........………………...………….………......12
Table of Contents
- NOTICE-
All warranty parts are provided through
Hitachi Customer Service.
All Servicers should call:
800-654-7013
Updated: 11/03/10 OR

L42A404
2
Caution for Safety
Please read this page before repair the TV.
The following safety precautions are designed to help you stay safe and prevent accidents during the repair work.
●Please take note of these cautionary flags.
WARNING This means "Potential to sustain injury or even death."
CAUTION This means "Potential to sustain breakage or irreparable damage."
●Also note these cautionary icons.
This means "CAUTION"
This means "MUST"
This means "POTENTIAL
ELECTRIC SHOCK"
This means "DO NOT"
WARNING
■Follow instructions. ■Must use same types of wires and components.
The cabinet, chassis, and labels
are parts that require attention.
You must follow the caution notes
and safety instructions presented
throughout this User Manual to
prevent damage to them or injury
to yourself.
■Prevent electric shock.
The TV uses special tubes and
tapes made from insulated
materials. Moreover, some
materials are kept from making
contact with the PWB for the sake
of safety. Internal leads are kept
from hot parts or high voltage
parts by means of clamps or
other measures. As such, you
must restored these parts to their
original conditions in order to
prevent electric shock or fire.
■Perform safety check when done.
Exercise caution while working
on the device as the TV contains
high voltage parts and supply. It
is possible to sustain severe
injury or death if you accidentally
touch the wrong parts. You must
disconnect the power supply
while servicing, reassembling, or
change parts. If you touch a live
connection it is possible to
sustain severe injury or death.
■Use recommended components.
Use only the recommended
components or components that
structurally identical to the
originals. This is to ensure safety
and reliability. Pay special
attention to parts in the parts list
and circuit diagrams marked with
. If you use
non-recommended components,
then electric shock or fire may
result.
Every part (such as removed
screws, components, and wiring)
must be restored to their prior
conditions after servicing. Be
sure to check everything that was
repaired for damage or mistakes.
Also measure the insulated
impedance with a meg-ohm
meter to confirm that the
impedance value is more than 4M
ohm. If the impedance value is
less than 4M ohm, then electric
shock or fire may result.

L42A404
3
PRECAUTIONS
●Cleaning the TV’s LCD screen panel
Before cleaning the TV, turn it off and disconnect the power plug from the power outlet. To prevent scratching or
damaging of the LCD screen face, do not knock or rub the surface with sharp or hard objects. Clean the screen with
a soft cloth moistened with warm water and dry with a second soft cloth. If it is not enough, then use a cloth with mild
detergent. Do not use harsh or abrasive cleaners.
●Cleaning the TV's cabinet
Use a soft cloth to clean the TV's cabinet and control panel. When excessively soiled, dilute a neutral detergent in
water, wet and wring out the soft cloth in it, gently clean the cabinet, and then wipe it down with a dry soft cloth.
Never use acid/alkaline detergents, alcoholic detergents, abrasive cleaners, powder soaps, OA cleaners, car wax,
glass cleaners, and so on. They will cause discoloration, scratches or cracks.
Features
●Enhanced definition LCD display panel
This specification applies to the 42.0 inch Color TFT-LCD Module T420HW06 V2. This LCD module has a TFT
active matrix type liquid crystal panel 1,920x1,080 pixels, and diagonal size of 42.0 inch. This module supports
1,920x1,080 mode. Each pixel is divided into Red, Green and Blue sub-pixels or dots which are arranged in vertical
stripes. Gray scale or the brightness of the sub-pixel color is determined with a 8-bit gray scale signal for each dot.
The T420HW06 V2 has been designed to apply the 8-bit 2 channel LVDS interface method. It is intended to support
displays where high brightness, wide viewing angle, high color saturation, and high color depth are very important.
●New High Gloss Black Frame
●(4) HDMI® (V.1.3 with CEC)
1080p60, 1080p24 Input Compatible
●New Multi-Function Remote Control
●Dynamic/Standard/Movie/Custom/Game
●Picture Memories
●3 Preset Color Temperatures
●Game Mode

L42A404
4
Dimensions

L42A404
5
General Specification
Video
Picture Mode Select among 5 pictures modes: Dynamic, Standard, Movie,
Custom, and Game.
Contrast Adjust picture contrast.
Brightness Adjust picture brightness.
Color Adjust color.
Tint Adjust tint.
Sharpness Adjust sharpness.
Color Temp. Set this to High for less intense color with more blue, set to
Medium for natural color and set to Standard for warm colors.
Noise Reduction Reduces conspicuous noise in the picture.
Backlight Adjust to increase or decrease the brightness of backlight.
Auto Movie Select the 3:2 Pull down detection feature Auto/Off. For a film like
picture.
Aspect Ratio Choose the picture format aspect ratio.
Reset Choose to Reset Video Settings to factory settings.
Audio
Sound Mode Selects 4 audio presets (Custom,Standard, Movie, News).
Bass Adjust the intensity of low frequencies.
Treble Adjust the intensity of high frequencies.
Balance Adjust the balance.
CONEQ Select sound equalizing mode.
Audio Source Select among three Audio Sources (Stereo, Mono, SAP).
Preferred Language Select Language options if available (Available for digital
channel).
Audio Language Select Language options if available.
Digital Output Select Optical Output options.
Internal Speakers Turn On/Off internal speakers.
Perfect Volume Adjust volume to be closer in level between channels.
Reset Resets all Audio settings the original condition.
Setup
Menu Language Choose English, French or Spanish OSD Language.
Time Set Clock Settings.
Sleep Timer Set Sleep Timer intervals (5 minutes ~ 4 hours).
Set Password Set the password for the Parental control access.
Parental Controls Ratings system to block various types of programs.
Closed Captions Feature to turn On/Off closed captions.
Digital Captions Feature to display DIGITAL dialogue/text.
Digital Caption Options Feature to change the appearance of the DIGITAL
CAPTIONS.
Analog Captions Feature to display ANALOG dialogue/text.
Energy Options Select Power Consumption Savings options.
HDMI-CEC Set to ON, this feature will enable simplified operation of compatible
HDMI CEC devices.
Input Labels Label Video Inputs, VCR, DVD, etc.
Component Options Adjust the Phase and applies Reset to any adjustments
made.
RGB Options Adjust Horizontal Position, Vertical Position, Clock, Phase and
Reset.
Reset AV & Setup Resets all Audio, Video and Setup settings to the original
condition.
Channels
Source Selects the type of signal to be used Cable or Air.
Signal Strength Access Signal Strength meter.
New Channel Scan Set Auto Channel Scan.
Add Channels to List Adds Channels to the List (Scanned channels remain
the same until New Channel Scan is performed).
Channel List Set Channel List.
Channel Labels Set Labels on the channels.
Favorite Channels Set the Favorite Channels.

L42A404
6
Firmware Upgrade
Equipments and materials
1. TV remote control
2. AC power 110V/ 60Hz
3. Flash storage
Preparations
Use PC to write software to a flash storage, press “on” button to start the TV. (Take L46S603 for example)
1. Insert the flash storage into the USB port, and you will see a picture in which you can choose “YES” or “NO”
(Picture1), you choose “YES”, and then the software will update automatically. (Picture 2)
2. After software update is finished, you put out the flash storage and restart the TV.
3. Press “menu+1999+select”, check whether software version is ok. (Picture 3 the fifth row)
Picture 1
Picture 2
Picture 3

L42A404
7
Adjustment
ADC adjustment
1. Press menu key and then press number key 1 Æ9 Æ9 Æ9. It will achieve the factory mode. The factory menu
follow picture:
2.Change TV, press the item “Current Source” to Component mode and change signal to Timing314(Component
720p) and Pattern 122(SMPTE Bar), press the item “Auto Color”;
3.Change TV, press the item “Current Source” to PC mode and change signal to PC TIMING 137(1024X768@60Hz)
Pattern 147 (16 Grays), press the item “Auto Color”.

L42A404
8
Troubleshooting
1). No Picture, No Sound
First, confirm the status of Stand-by / On lamp (LED), then survey by following the flowchart as shown below.
Status of Stand-by / On lamp (LED) Estimated cause, method of survey
Not lighting Confirm the connection of AC cord is complete, and AC
switch is turned on, then forward to (1).
Lighting in red Power save mode of Video or PC input. It is not defect.
Lighting in red Turn power on by remote controller.
If it does not turn power on, forward to (2).
Lighting in blue Forward to (2).
(1) Stand-by / On lamp (LED)
is not lighting
The voltage of
pin No.11,No.12 of
CN701 on
Main Board is 5V?
Power Board
No
Yes
Main Board

L42A404
9
Main Board
No
Power Board
LCD Panel.
The voltage of
pin No.3,No.4 of CN701
on Main Board is 12V?
The voltage of
pin No.11 or 12 of CN701
in Main Board is 5V?
Yes
No Main Board
LCD Panel.
Yes The voltage of
pin No.1 to 4 of CN405
in Main Board is 12V?
No Yes
Main Board
Yes
(2) Stand-by / On lamp (LED)
is lighting in red or blue
LED Indicates
blue or red?
red
blue
Turn R/C power on, then
LED change to blue?
No
Backlight of LCD Panel
is lighting?
Yes
No

L42A404
10
2). No Picture, Picture Failed (Color Failed, Dark Picture, Beat Noise, Etc.)
First, confirm the connection of all connectors between Board's, then survey by following the flowchart as shown
below.
CN701 (1) 3.3V
(2) 0~3.3V
(3)~(4) 12V
(5)~(7) 0V
(8)~(9) 24V
(10)~(12) 5V
No Picture, Picture failed
(Color failed, Dark picture,
Beat noise, etc.)
Occured at only
Video1 input (CVBS), or
Video2 input (CVBS, S2)?
Main Board
No
Yes
Main Board
Voltage of all pin of
CN701 on Main Board is
correct?
Power Board
No
Yes