Sharp LL-T1820-H User manual

qSERVICE MANUAL
CONTENTS
Parts marked with " ! " are important for maintaining the safety of the set. Be sure to replace these parts with specified
ones for maintaining the safety and performance of the set.
SHARP CORPORATION This document has been published to be used
for after sales service only.
The contents are subject to change withoutnotice.
CODE : 00ZLLT1820SME
LCD MONITOR
LL-T1820
MODEL LL-T1820
CHAPTER 1. OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION . . . 1 – 1
CHAPTER 2.
CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS . . . . 2 – 1
CHAPTER 3. DISASSEMBLY AND ASSEMBLY. . . . . . . . . . . . . . . . . . . 3 – 1
CHAPTER 4. TROUBLE SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 – 1
CHAPTER 5. WAVE FORM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 – 1
CHAPTER 6. BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 – 1
CHAPTER 7. CIRCUIT DIAGRAM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 – 1
CHAPTER 8. PARTS LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 – 1
-B
-H

LL-T1820-H/B SERVICE PRECAUTION
■
■■
■SERVICE PRECAUTION
[OVERCURRENT PROTECTION ELEMENT FOR USB OUTPUT OF THE POWER UNIT]
The USB output (5V, connector CN2) of the power unit is provided with an overcurrent protection element (Part Number PTC101) of PTC (positive
characteristics thermister). Its resistance becomes high when heated by an overcurrent, and shuts down the circuit similarly with a fuse. When it is
cooled down by non-conduction, its resistance returns to a low level and allows a current to flow through the circuit.
If a user erroneously allows an overcurrent to flow through an USB device, the PTC101 cuts off the current. When repaired, it returns to normal. Note
this operation of the PTC 101 in case of an USB error.

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LL-T1820-H/B OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION
1 – 1
CHAPTER 1. OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION
1. SPECIFICATIONS
■
■■
■ PRODUCT SPECIFICATIONS
• LCD display
18.1 inches (46 cm measured diagonally)
Advanced-Super-V and Anti Glare Low Reflection TFT LCD module
• Resolution (max.)
SXGA 1280
u 1024 pixels
• Displayable colors (max.)
16.77 million colors (8 bit)
• Brightness (max.)
220cd/m2
• Dot pitch
0.2805(H) 0.2805(V) mm
• Contrast ratio
400 : 1
• Angle of visibility
Left-right 170° ; Up-down 170°
• Screen display size
Horizontal 359 mm
u Vertical 287.2 mm
• Video signal
Analog:Analog RGB (0.7Vp-p) [75Ω]
Digital: DVI standard based on 1.0
• Sync signal
Separate Sync (TTL level: +/-), Sync on Green,
Composite Sync (TTL level: +/-)
• Expansion compensation
Digital screening (enlargement of display to correct VGA/SVGA/XGA)
[1:1, expansion (fixed aspect ratio), expansion (total screen surface)]
• Plug & Play
VESA: DDC2B compatible
• Power management
VESA: based on DPMS
DVI: based on DMPM
• Input signal terminal
Digital / Analog:29 pin DVI-I
u 2
• USB hub function
1 upstream port, 2 downstream ports
(bus-powered hub based on USB standard Rev 1.1)
• Screen tilt
Upward 0° - 30°; downward 0° - 5°
• Screen swivel
90° from left through right
• Power supply
AC100-240V, 50/60Hz (Use special AC adapter, type NL-A03E of
Sharp Corporation.)
• Temperature of operating environment
5 - 35°C
• Power consumption
Maximum 57W (2.9W when in power-saving mode)
(Use special AC adapter.)
• Dimensions (W
u D u H)
395 mm
u 213 mm u 427 mm
• Weight (excluding AC adapter)
Approx. 8.9 kg, Display area only, approx. 5.7kg
■
■■
■ DIMENSIONS (Units: mm)
Special AC adapter
Option
Digital signal cable: Approx. 2.0 m
Analogue signal cable:Approx. 2.0 m
USB cable: Approx. 1.8 m
395
213
427 324
507
324
463 395
543
277
Approx. 2.0 m
Approx.W 120 mm uD 60 mm uH 35 mm

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LL-T1820-H/B OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION
1 – 2
Relevant signal timings (analog)
• Recommended resolution is 1280 u 1024.
• All are compliant only with non-interlaced.
• Frequencies for Power Macintosh and the Sun Ultra series are refer-
ence values. To connect, another adapter (purchased separately)
may be required.
• If the monitor is receiving timing signals that are not compatible, [OUT
OF TIMING] will appear. Follow your computer's instruction manual
to set the timing so that it is compatible with the monitor.
• If the monitor is not receiving any signal (synch signal), [NO SIGNAL]
will appear.
Relevant signal timings (digital)
• Recommended resolution is 1280 u 1024.
• All are compliant only with non-interlaced.
• A computer with an output terminal conforming to DVI (DVI-D24 pin
or DVI-I29 pin) and with SXGA output capability can be connected
here.
(Depending on the type of computer to be connected, the display may
not work correctly.)
• If the monitor is receiving timing signals that are not compatible, [OUT
OF TIMING] will appear. Follow your computer's instruction manual
to set the timing so that it is compatible with the monitor.
• If the monitor is not receiving any signal (synch signal), [NO SIGNAL]
will appear.
The DVI-I input connector pin
Display mode Hsync
(kHz) Vsync (Hz) Dot frequency (MHz)
VESA 640
u 480 31.5kHz 60Hz 25.175MHz
37.9kHz 72Hz 31.5MHz
37.5kHz 75Hz 31.5MHz
800
u 600 35.1kHz 56Hz 36.0MHz
37.9kHz 60Hz 40.0MHz
48.1kHz 72Hz 50.0MHz
46.9kHz 75Hz 49.5MHz
1024
u 768 48.4kHz 60Hz 65.0MHz
56.5kHz 70Hz 75.0MHz
60.0kHz 75Hz 78.75MHz
1152
u 864 67.5kHz 75Hz 108.0MHz
1280
u 960 60.0kHz 60Hz 108.0MHz
1280
u 1024 64.0kHz 60Hz 108.0MHz
80.0kHz 75Hz 135.0MHz
US text 720
u 400 31.5kHz 70Hz 28.3MHz
Power
Macintosh
series
640
u 480 35.0kHz 66.7Hz 30.2MHz
832
u 624 49.7kHz 74.6Hz 57.3MHz
1024
u 768 60.2kHz 75Hz 80.0MHz
1152
u 870 68.7kHz 75Hz 100.0MHz
1280
u 1024 64.0kHz 60Hz 108.0MHz
80.0kHz 75Hz 135.0MHz
Sun Ultra
series 1024
u 768 48.3kHz 60Hz 64.13MHz
53.6kHz 66Hz 70.4MHz
56.6kHz 70Hz 74.25MHz
1152
u 900 61.8kHz 66Hz 94.88MHz
71.8kHz 76.2Hz 108.23MHz
1280
u 1024 71.7kHz 67.2Hz 117.01MHz
81.1kHz 76Hz 134.99MHz
Display mode Hsync
(kHz) Vsync (Hz) Dot frequency (MHz)
VESA 640
u 480 31.5kHz 60Hz 25.175MH
37.9kHz 72Hz 31.5MHz
37.5kHz 75Hz 31.5MHz
800
u 600 37.9kHz 60Hz 40.0MHz
48.1kHz 72Hz 50.0MHz
46.9kHz 75Hz 49.5MHz
1024
u 768 48.4kHz 60Hz 65.0MHz
56.5kHz 70Hz 75.0MHz
60.0kHz 75Hz 78.75MHz
1152
u 864 67.5kHz 75Hz 108.0MHz
1280
u 960 60.0kHz 60Hz 108.0MHz
1280
u 1024 64.0kHz 60Hz 108.0MHz
US text 720
u 400 31.5kHz 70Hz 28.3MHz
No. Function No. Function
1 TMDS data 2- 16 Hot plug detection
2 TMDS data 2+ 17 TMDS data 0-
3 TMDS data 2/4 shield 18 TMDS data 0+
4 N.C. 19 TMDS data 0/5 shield
5 N.C. 20 N.C.
6 DDC clock 21 N.C.
7 DDC data 22 TMDS clock shield
8 Analogue vertically
synchronised signal 23 TMDS clock +
9 TMDS data 1- 24 TMDS clock -
10 TMDS data 1+ C1 Analogue red image signal
11 TMDS data 1/3 shield C2 Analogue green image signal
12 N.C. C3 Analogue blue image signal
13 N.C. C4 Analogue horizontally
synchronised signal
14 +5V C5 Analogue GND
15 GND

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LL-T1820-H/B OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION
1 – 3
Power management
The monitor is based on the VESA DPMS*1and the DVI DMPM*2stan-
dards.
To activate the monitor's Power Management function, both the video
card and the computer must conform to the VESA DPMS standard and
the DVI DMPM standard.
*1 DPMS: Display Power Management Signalling
*2 DMPM: Digital Monitor Power Management
DDC (Plug & Play)
This monitor supports the VESA DDC (Display Data Channel) standard.
DDC is a signal standard for carrying out Plug & Play functions on the
monitor or PC. It transfers information such as degree of resolution
between the monitor and PC. You can use this function if your PC is
DDC compliant and if it is set so that it can detect the Plug & Play mon-
itor.
There are many varieties of DDC due to the differences between sys-
tems. This monitor works with DDC2B.
2. TECHNICAL SPECIFICATIONS
* Specifications and a part of the appearance are subject to change without notice.
PRODUCT DESCRIPTION
DPMS mode Screen Power
consumption H-sync V-sync
ON Display on 51W Yes Yes
STANDBY Display off 2.9W No Yes
SUSPEND Yes No
OFF No No
DPMS mode Screen Power consumption
ON Display on 51W (USB OFF)/57W (USB ON)
OFF Display off 2.9W
Item MIN TYP MAX Unit
Power supply voltage AC 90 100 110 V
Working temperature range +5
. +35 °C
Storing temperature range -20
. +60 °C
Humidity range 20
. 85 %RH
Visual angle range Vertical (CR
u 10) m 70 m 85 . Temperature
Horizontal (CR
u 10) m 70 m 85 . Temperature
Contrast ratio(CR) (θ= 0°)
. 400 ..
Response speed Leading (τr) . 20 . ms
Trailing (τd)
. 5 . ms
Screen white chromaticity (X) 0.278 0.308 0.333
.
(Y) 0.290 0.320 0.350 .
White surface luminance (YL) 180 220 . cd/m2
Module model number LQ181E1LZ30
1 2 3 4 5 6 7 9 11
12
10
13
8
1. INPUT button: To switch between the signals input termi-
nals. (Input terminal 1
0 Input terminal 2)
2. MENU button: This button is used to pop-up, select and
close the OSD (On Screen Display) Menu.
3. SELECT button: This button is used to select menu options
when the OSD Menu is displayed.
4.
ed buttons: When the OSD Menu is displayed:
These buttons are used to increase or
decrease the value of a selected option.
When the OSD Menu is not displayed:
These buttons are used to adjust backlight
brightness .
5. Power button
6. Power LED: This LED is lit green when in use and orange
when in power-saving mode.
7. USB port (downstream: 2 ports)

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LL-T1820-H/B OUTLINE OF THE PRODUCT, NOMENCLATURE AND FUNCTION
1 – 4
HEIGHT ADJUSTMENT, ANGLE ADJUSTMENT,
ROTATION (LONG HEIGHT/WIDTH)
Caution: • Pressure from hands on the LCD panel could cause dam-
age.
• Be careful not to allow your fingers to be pinched.
Height adjustment
Adjust to an easy to view height.
Angle adjustment
Adjust to an easy to view angle.
Rotation (long height/width)
The display can be rotated for a long height or width to suit the dis-
played content.
• Before rotating, move the display to its uppermost position. If the dis-
play is rotated while it is set low, it will contact the stand and could
lead to damage.
• The display can only be rotated through a range of 90°. Applying
excessive force may cause malfunction.
• Do not apply excessive force when the cable is connected.
To set to long height
Gently turn in the clockwise direction (to 90°).
To set to long width
Gently turn in the counterclockwise direction (to 90°).
Note: The orientation of the display can be changed using Pivot Soft-
ware.
8. USB port (upstream: 1 port)
9. DVI-I input terminal: The computers digital RGB output terminal or
analogue RGB output terminal can be con-
nected here.
For a digital signal input: It can be connected
to a computer with a DVI-compatible output
terminal (DVI-D24 pin or DVI-I29 pin) and
which has SXGA output ability. Depending on
the computer to be connected, correct display
may or may not be possible.
10. Security lock anchor: By connecting a security lock (purchased
separately) to the security lock anchor, the
monitor is fixed so that it cannot be trans-
ported.
The security slot works in conjunction with
Kensington Micro Saver Security Systems.
11. Power terminal
12. Main power switch
13. Ventilation openings: Note: Never block the ventilation openings as
this may lead to overheating inside the moni-
tor and result in malfunction.
80mm
30
5
45
45

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 1
CHAPTER 2. CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
1. CONNECTING THE MONITOR AND TURNING THE MONITOR ON AND OFF
Caution: • When connecting, ensure that both the monitor and com-
puter are switched off.
• Be careful not to overly bend the cable or add extension
cords as this could lead to malfunction.
Cable storage
If necessary, excess cable can be housed in the stand.
1. Remove the cover.
Gently pull the top of the cover towards yourself.
2. Run cable along the back of the stand.
Pass cable in front of the stand, and then bring it through the back.
• If the display is to be rotated, first house the cables with the dis-
play in the long height position, so there is sufficient length when
the display is turned.
3. Refit the cover.
Be careful not to pinch the cable.
• If the cover is hard to refit, do not force it. Check whether cables
are trapped.
Caution: If the display is to be rotated, first house the cable, and then
check while gently turning the display. If it cannot be turned,
rehouse the cable with sufficient slack. (If there is insufficient
cable length, rotation will be impossible. Forcing rotation may
cause cable disconnection.)
CONNECTING THE MONITOR TO A COMPUTER
Connecting the monitor to a computer using the accessory signal cable.
• This monitor has two input terminals to enable connection to two
computers. The monitor comes with one analog signal and one digital
signal cable. If both connections are analog, or both are digital, you
will need another signal cable sold separately.
• Digital signal cable: model name NL-C01E
• Analog signal cable: model name NL-C02E
Analog RGB connection
Using the accessory analog signal cable, connect to the analog RGB
output terminal of the computer.
• Paying attention to connector direction, firmly insert the signal
cable to terminal, and then tighten the screws at both sides.
If connecting to a D-sub 15 pin 2 row Apple Power Macintosh, attach a
Macintosh conversion adapter (to be purchased separately) to the ana-
log signal cable.
Input terminal 1 and 2
You can connect to
either side.
Analog RGB output
terminal
Analog signal cable
Macintosh conversion adapter

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 2
Digital RGB connection
Using the accessory digital signal cable, connect with the digital RGB
output terminal of the computer.
• For digital RGB connection, the monitor has an input for connecting
to a computer with a DVI-compatible output connector (DVI-D 24 pin
or DVI-I 29 pin) and SXGA output capability. (Depending on the type
of computer to be connected, the display may not work correctly.)
• Paying attention to connector direction, firmly insert the signal
cable to terminal, and then tighten the screws at both sides.
Set the monitor as follows when establishing a digital connection with a
Power Mac using an ADC-DVI adapter made by Belkin. (Operation has
been checked with the Power Mac G4 M7627J/A)
• Perform settings with the Power Mac power supply off.
1. After connecting the power cord, turn on the monitor’s main power.
2. Press the
e button and d button simultaneously, and while doing
this press the POWER button (i.e. turn the power on).
3. Set the input terminal to which the Belkin ADC-DVI adapter is con-
nected to ON.
Use the SELECT button to select [INPUT1] or [INPUT2], and use
the
ed buttons to select [ON] and [OFF].
• Do not set to [ON] if you are not using a Belkin ADC-DVI adapter,
as this may result in incorrect display.
4. Press the power button, and turn off the monitor power.
This completes setting.
CONNECTING THE MONITOR TO A POWER SOURCE
CONNECTING A USB DEVICE
This monitor is equipped with a USB standard (Rev. 1.1) self-powered
hub.
Downstream (2 ports)
Each of these ports enables connection of a USB device with working
current up to 500 mA.
Upstream (1 port)
This enables connection of a USB compatible computer or USB hub.
Notes: • If a USB cable is required, please use the one included.
• Before connecting, ensure that the shape of the USB cable
connector is correct.
• For information regarding the USB function (such as set-up)
please refer to the operation manual of the computer to be
connected.
• Some computers, OS and other devices may not be able to
be activated. To ascertain a certain device’s USB compatibil-
ity, please contact the manufacturer of the device.
Input terminal 1 and 2
You can connect to
either side.
Digital RGB output
terminal
Digital signal cable
Power terminal
AC outlet
Power cord
Upstream
USB cable
Downstream

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 3
TURNING THE POWER ON
1. Turn on the main power of the monitor.
• When switching the main power switch on and off, always wait
for an interval of at least 5 seconds. Rapid switching may result
in malfunction.
2. Press the monitor’s POWER button.
The power LED will light up orange.
3. Turn on the computer.
When a signal is input from the computer, the power LED lights up
green, and the screen is displayed (After power is turned on, it may
take a little time until the screen is displayed.)
• If the input terminal to which the computer is connected has not
been selected, the screen will not be displayed. If necessary,
perform input terminal switching. (right column)
Notes: (when using an analog signal)
• If using the monitor for the first time or after having changed the sys-
tem settings during use, perform an automatic screen adjustment.
• When connecting to a notebook, if the notebook computer’s screen is
set so that it is displaying at the same time, the MS-DOS screen may
not be able to display properly. In this case, change the settings so
that only the monitor is displaying.
CHANGING BETWEEN INPUT TERMINALS
Use the INPUT button to switch between signal input terminals.
The input signal type (ANALOG/DIGITAL) is displayed within angle
brackets < >.
TURNING THE POWER OFF
1. Turn the computer off.
2. Press the monitor’s POWER button.
The Power LED will disappear.
If the monitor will not be used for a long time, turn off the main power
switch of the monitor, and remove the power plug from the outlet.
Main power switch
ON
Press power button Turn on the computer
power supply.
INPUT-1
< > INPUT-2
< >
INPUT
Input terminal 1 Input terminal 2
Turn the computer off
OFF
Press power button

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 4
2. INSTRUCTIONS FOR ATTACHING A VESA COMPLIANT ARM
An arm or stand based on the VESA standard (purchased separately)
can be attached to the monitor.
Procurement of the arm or stand is at the customer’s discretion.
Arms or stands able to be used
Attachments must satisfy the following.
• Compatible with the VESA standard
• Have a gap of 100 mm x 100 mm between the screw holes on the
section to be attached
• Not be likely to fall off or break off after being attached to the monitor.
How to attach the arm or stand
• Be careful not to overly bend the cable or add extension cords as this
could lead to malfunction.
• While following these instructions, please also refer to the installation
instructions in the operation manual included with the arm or stand.
1. Remove the cable.
2. Spread out a soft cloth on a suitable horizontal surface.
3. Being careful not to damage the monitor, gently lay the monitor on it
display-side down.
Caution: Securely grasp both the display and stand, and gently tip over.
When the monitor is inclined, the stand may suddenly pop out
and cause injury.
4. Remove the four screws and then remove the stand from the moni-
tor.
Notes: • The stand is specially made for use with this monitor. Once
having removed the stand, never attempt to attach it to
another device.
• Once having removed the screws, store them together with
the stand and if the stand is ever re-attached be sure to use
the original screws. Using different screws could lead to a
malfunction.
Caution: Do not disassemble the stand. Parts may spring out and cause
injury.
5. Attach the arm to the monitor with the four screws.
Note: The screws used to attach the arm should be M4 screws with a
length of 8 mm ~ 10 mm protruding from the surface to be
attached. Using different screws could lead to malfunction or may
lead to the monitor falling off,internal damaged,personal injury.
8 - 10mm
Screw used to attach arm
Arm
Part of monitor to which arm is attached

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 5
3. ADJUSTMENT
3-1. ADJUSTMENT METHOD
6) Version display (for service)
Power ON
Display the software version.
Press the above two buttons at same time, and while turn the power on.
7) Aging (for service)
Power ON
Red 3 Green 3 Blue 3 Yellow 3 Purple 3 Light Blue 3 White 3 Black
When the test is terminate, Power off.
LL-T1820
VERSION 1.00
2001. 12. 10
CHECKSUM BOOT
MENU SELECT
MENU
MENU
1) Adjusting the backlight Buttons
2) Resetting all adjustment values
Power ON
Power ON
Press the above two buttons at same time, and while turn the power on.
3) ADJUSTMENT menu reser Press the two buttons at same time.
4) Adjustment lock function
While pressing the MENU button, turn the power on.
5) Automatic screen adjustment
MENU ADJUSTMENT AUTO
SELECT CLOCK
SELECT PHASE
SELECT H-POS
SELECT V-POS
SELECT GMMA
SELECT HUE
SELECT SATURATION
MENU GAIN
CONTROL AUTO
SELECT BLACK LEVEL
SELECT CONTRAST
MENU
COLOR
CONTROL
COLOR MODE (sRGB, STD, VIVID)
COOL STD
WHITE BALANCE WHITE BALANCE
WARM USER
SELECT R-CONTRAST
SELECT
SELECT
G-CONTRAST
B-CONTRAST
MENU MODE SELECT OSD H-POSITION
SELECT OSD V-POSITION
SELECT 400 LINES
OSD PIVOT
SELECT SCALING
SELECT LANGUAGE
SELECT
MENU
MENU
MENU
SELECT
(for ANALOG) buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
buttons
SELECT buttons
END
MENU SELECT
SELECTMENUINPUT

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LL-T1820-H/B CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS
2 – 6
3-2. ADJUSTMENT ITEM LIST
BUTTON ITEM ADJUSTMENT DESCRIPTION
MENU MENU 1:
ADJUSTMENT MANUAL CLOCK 0~255 CLOCK: The figure below demonstrates how to adjust so that vertical flicker noise is not emitted.
(
ed buttons)
MENU 1
4
MENU 2
4
MENU 3
4
MENU 4
4
MENU END
PHASE 0~31 PHASE: The figure below demonstrates how to adjust
so that horizontal flicker noise is not emitted.
(
ed buttons)
H-POS 0~ H-POS (horizontal positioning) and
V-POS (vertical positioning)
To center the screen image within the boundaries of the
screen, adjust the left-right (H-POS) values and the up-
down (V-POS) values. (
ed buttons)
V-POS 0~
AUTO Automatic screen adjustment
Options in the ADJUSTMENT Menu can be adjusted
automatically
(CLOCK, PHASE, H-POS V-POS).
MENU 2:
GAIN CONTROL MANUAL BLACK LEVEL 0~63 BLACK LEVEL: Total screen brightness can be adjusted while watching the color pattern.
(
ed buttons)
CONTRAST 0~100 CONTRAST: While watching the color pattern, adjust-
ments can be made so that all gradua-
tions appear. (
ed buttons)
AUTO GAIN CONTROL Menu
AUTO: Every menu option is automatically adjusted
using the Auto Gain Control function.
MENU 3:
COLOR CONTROL COLOR MODE sRGB, STD, VIVID STD: Displays image with the color tone results from
original scheme of liquid crystal panel.
sRGB: sRGB is international standard of color represen-
tation specified by IEC (International Electrotechni-
cal Commission). Color conversion is made in
taking account of liquid crystals characteristics and
represents color tone close to it original image.
VIVID: Displays an image with dynamic and VIVID pri-
mary colors.
WHITE BALANCE COOL • STD • WARM
(5 levels),
USER R • G • B: 0~100
WHITE BALANCE Menu
COOL : Color tone bluer than standard
• : Color tone slightly bluer than standard
STD : Color tone standard setting
• : Color tone slightly redder than standard
WARM : Color tone redder than standard
USER
R-CONTRAST :
e button for blue-green
d button for red
G-CONTRAST :
e button for purple
d button for green
B-CONTRAST :
e button for yellow
d button for blue
GAMMA 0~ Adjust so that dark and bright images are easy to see. If
the screen is dark and hard to see, increase the numerical
value. If it is bright and hard to see, lower the numerical
value. (
ed buttons)
HUE 0~ Hue can be adjusted. (
ed buttons)
SATURATION 0~ Color saturation can be adjusted. (
ed buttons)
At the minimum value, the screen is black and white.
MENU 4:
MODE SELECT OSD H-POSITION OSD H-POSITION (OSD horizontal position) The position of the OSD display can be moved to the
left and right. (
ed buttons)
OSD V-POSITION OSD V-POSITION (OSD vertical position)
The position of the OSD display can be moved up and
down. (
ed buttons)
400 LINES 640 • 720 400 LINES (degree of resolution)
You can specify the horizontal resolution of a 400-line
screen when using US text, etc.
(
ed buttons)
640: 640
u 400 dot mode
720: 720
u 400 dot mode (US text etc.)
SCALING 1~5 SCALING (Level of scaling)
The sharpness of the image can be adjusted.
(
ed buttons)
LANGUAGE 7 countrys
DEUTSCH, ENGLISH,
ESPANOL, FRANCAIS,
ITALIANO, NETHER-
LAND, SVENSKA
LANGUAGE
Messages displayed on the screen and OSD Menu con-
tents can be changed to the following languages.
Dutch, English, French, German, Spanish, Italian,
Swedish.
SELECT Select the item
< > 0~31 Adjusting the backlight
POWER OFF

PC-UM10M
LL-T1820-H/B DISASSEMBLY AND ASSEMBLY
3 – 1
CHAPTER 3. DISASSEMBLY AND ASSEMBLY
15
2
C
1
D
3
E
4
5
6
7
8
A
AA
B
B
B
B
B
C
C
C
C
C
F
J
GH
I
I
I
I
IK
K
KL
L
L
9
12
10
11
13
14
N
N
N
O
P
R
O
OQ
1. Separating the display from the stand
1) Remove the four screws Aand remove the display 1from the stand 2.
2. Display
1) Remove the seven screws Band remove the rear cabinet 3.
2) Remove the seven screws Cand remove the PWB shield 4.
3) Remove the harnesses D, F. Remove the three screws Eand remove the
*** PWB 5.
4) Remove the harnesses G, H. Remove the 18 screws and remove the main
PWB 6.
5) Remove the harness J. Remove the five screws Kand remove the power
supply PWB 7.
6) Remove the eight screws Land remove the angle 8from the LCD unit 9.
7) Remove the front cabinet F.
8) Remove the seven harnesses N. Remove the three screws Oand remove
the inverter PWB G.
9) Remove the six screws P, H, Q. Remove the angles H, I, Jfrom the
LCD unit K.

PC-UM10M
LL-T1820-H/B DISASSEMBLY AND ASSEMBLY
3 – 2
C
D
1
2
A
A
6
9
13
14
15
11
12
B
B
D
E
F
G
I
H
H
H
I
I
7
3
4
5
8
10
3. Stand
1) Remove the five screws Aand separate the *** 1from the base 2.
2) Remove the cover 3.
3) Remove the six screws Band remove the *** 4.
4) Remove one screw Cand remove the cover 5.
5) Remove the two screws Dand remove the *** 6.
6) Remove the two screws Eand remove the *** 7.
7) Pull the *** 9out of the *** 8.
8) Remove the two screws Fand remove the *** F.
9) Remove one screw Gand remove the *** G.
10) Remove the three screws Hand remove the *** H.
11) Remove the 17 screws and remove the *** I, *** Jand *** K.

PC-UM10M
LL-T1820-H/B TROUBLE SHOOTING
4 – 1
CHAPTER 4. TROUBLE SHOOTING
(Yes)
(Yes)
(Yes)
(Yes)
(Yes)
(Yes)
Green LED comes on when the power button is
pressed?
The screen is displayed properly in each video
mode?
AC cable is connected to the power supply
unit?
Input signal port is the one to which analog
signal cable is connected?
Test terminals LD416, LD417, and LD418 are
DC+3.3V?
Test terminal LD628 changes its level when
POWER switch is turned on and off?
Press INPUT key to switch over to the
correct input signal port.
Check the power supply unit and power
supply cable and their connections.
Check DC+5V power supply line (DV5A)
and POWER_CTL1 signal and circuits
around 0808.
Check DC+5V power supply line (AV5) and
POWER_CTL1 signal and circuits around
0808.
Check MAINPW signal and areas around
CN800.
Remove the analog signal cable. After a short
while time, the LED color changes form green
to orange.
(Yes)
(Yes)
(No)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
(No)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(Yes)
(No)
(No)
(No)
Perform 1
B/L is lit?
No error.
Check AC cable connection.
Check power supply unit switch.
Check circuits around IC600.
Check circuits around IC400.
Check RESET circuit around IC602.
Check IC601 and clock circuit around X600.
Check SW100 and circuits around IC100.
The power supply unit is switched on?
SW100 is on 1st pin side?
Test terminal LD805 is DC+5V?
8th pin of 0808 is DC+5V?
4th pin of IC602 is in H level (DC+5 V)?
Test terminal LD809 is DC+5V?
C610-side terminal signal of X600 is normal?
Test terminal LD634 is DC+3.3V?
1
Perform 2
Perform 3
Perform 4

PC-UM10M
LL-T1820-H/B TROUBLE SHOOTING
4 – 2
(No)
(No)
(No)
(No)
(Yes)
(Yes)
(Yes)
(No)
(Yes)
(Yes)
(No)
(Yes)
(Yes)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(Yes)
(Yes)
(No)
(No)
The port from which the analog signal cable
was removed is the input signal port selected?
48th pin and 49th pins of IC601 are in H level
(DC+3.3V)?
LD618 and LD621 are in H level (about
DC+1.9V)?
LD801 is less than DC+1.0V at maximum
brightness?
1st pin of CN2, CN3, CN4, CN5, CN6, and CN7
on inverter PWB unit is about 750 Vrms? (Use
caution not to get electric shock accident. Use
a high-voltage probe (more than 100:1) for
measuring voltage.)
Check analog signal cable and CN100
(CN200).
Check SDA and SCL signals and circuits
around IC401 and IC601.
Press INPUT key to switch over to the
correct input signal port.
Check the power unit and cable and their
connections, and DC+12V power supply
line.
Check BL_EN signal and circuits around
CN801.
Check BRT_VR signal and circuits around
IC603.
Signal waveforms of test terminals LD303,
LD304 (LD310, LD311) are normal?
Signal waveforms of test terminals LD305,
LD306 (LD312., LD313) are normal?
Signal waveforms of 31st and 32nd pins of
IC401 are normal?
Check SW PWB and SW cable and their
connections.
48th pin of IC601 is in H level (DC+3.3V)?
continued from 1
LD618 is H in level (about DC+1.9V)?
Check SW PWB and SW cable connections.
Test terminal LD804 is DC+12V?
LD800 is in H level (DC+5V)?
Check lamp inside LCD module.
Check circuits around IC601.
Check Q600 and its surrounding circuits.
Replace inverter PWB unit with a new one.
Check circuits around IC601.
Check Q600 and its surrounding circuit.
Check circuits around IC300 and IC301.
2
3

PC-UM10M
LL-T1820-H/B TROUBLE SHOOTING
4 – 3
(No)
(No)
(No)
(Yes)
(Yes)
(No)
(No)
(Yes)
(No)
(Yes)
(Yes)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(Yes)
(Yes)
(No)
(No)
(No)
(Yes)
(Yes)
(Yes)
(Yes)
(No)
(Yes)
(No)
(No)
(No)
(Yes) (No)
(No)
(Yes) (No)
(Yes)
(Yes)
Check DC+5V power supply line (AV5) ,
POWER_CTL1 signal, and circuits around
Q808.
Check DC+5V power supply line (PV5) ,
POWER_CTL3 signal, and circuits around
Q800.
Check the power supply unit and cable and
their connections, and POWER_CTL1
Check DC+2.5V power supply line (DV25),
POWER_CTL1 signal, and circuits around
IC800.
Check DC+12V power supply line (LCDV),
POWER_CTL2 signal, and circuits around
Q800.
Check OSC500 and clock circuit around
IC502.
Clock (R517) and DE (R515) signal outputs
are normal?
ADJUSTMENT and MODE SELECT are set
properly?
Signal waveform of test terminal LD510 is
normal?
ADJUSTMENT and MODE SELECT are set
properly?
Adjust according to "screen adjustment
procedure".
Adjust according to "screen adjustment
procedure".
Check circuits around IC300, IC301, and
IC401.
Check circuits around IC701, and CN700
and LCD module.
Check DC+5V power supply line (DV5A),
POWER_CTL1 signal, and circuits around
Q808.
Test terminals LD419, LD515, and LD700 are
DC+3.3V?
Signal waveform of test terminal LD500 is
normal?
Test terminals LD416, LD417, and LD418 are
DC+3.3V?
8th pin of Q808 is DC+5V?
Test terminal LD809 is DC+5V?
Test terminal LD810 is DC+5V?
Test terminal LD807 is DC+12V?
Test terminal LD509 is DC+2.5V?
TP801 is DC+12.0V?
36th pin of LC601 is in H level (DC+5V)?
The entire LCD screen is white?
The entire LCD is black?
The size of LCD screen is abnormal?
LCD screen jitters or flickers?
Check circuits around IC400.
Check circuits around IC402.
Check circuits around IC601.
Test terminal of LD701 is DC+12V?
Check circuits around X600 and IC601.
Check circuits around IC501.
Check circuits around CN700.
Check circuits around IC401.
Check circuits around IC501.
4

PC-UM10M
LL-T1820-H/B TROUBLE SHOOTING
4 – 4
(No)
(No)
(No)
(Yes)
(Yes)
(Yes)
(Yes)
(No)
(No)
(Yes) (No)
(No)
(Yes)
(Yes)
(Yes)
(No)
(Yes)
(No)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(No)
(Yes)
(Yes)
(No)
(Yes)
(Yes)
(No)
(No)
(Yes)
(Yes)
GAIN CONTROL and WHITE BALANCE
are set properly?
Analog color signal output (C302, C304,
C306, C317, C320, and C322) is normal?
Digital color signal output of IC401(ID0
ID47) is normal?
Digital color signal output of IC501 (OD0
OD47) is normal?
Check circuits around IC701, and CN700
and LCD module.
Check circuits around IC401, IC403, and
IC601.
Digital color signal output of IC401 (ID0
ID47) is normal?
Press INPUT key to switch over to the
correct input signal port.
Check CN100 and 200, and signal source
and digital signal cable.
Check circuits around IC100, IC102, IC103,
IC200, and IC201.
Check CN100 and 200, and signal source
and digital signal cable.
Display is normal in composite sync and sync-
on-green signal input.
Adjustment settings are stored after display
screen is adjusted?
AUTO function of GAIN CONTROL operates
properly?
Input signal port is the one to which digital
signal cable is connected?
Waveforms of IC103s and 201s 5th and 6th
pins change normally when resolution is
changed?
Test terminals LD100, LD101, LD200, LD201,
LD202, LD203, LD204, LD205 are DC+3.3V?
CN100 and 200 signals (at 1st, 2nd, 9th, 10th,
17th, 18th, 23rd, and 24th pins) are normal?
IC101 and IC203 signal output (ID0 ID47,
HIS, IVS,ICK, IACT) are normal?
LCD screen color is abnormal?
Input is changed over properly?
No error.
Display is normal in analog input?
TP100 and 200 are in H level (DV+5V)?
Check circuits around IC501.
Adjust according to "screen adjustment
procedure".
Check circuits around IC401.
Check circuits around IC401 and IC501.
Check circuits around IC501 and IC701.
Check circuits around IC401 and IC403.
Check circuits around IC601.
check circuits around IC601 and IC604.
Check circuits around IC401.
First, check with analog signal input.
Check circuits around IC400.
Check circuits around IC101 and IC203.
continued from 4
5

PC-UM10M
LL-T1820-H/B WAVE FORM
5 – 1
CHAPTER 5. WAVE FORM
Waveform measurement condition: Input each of the display patterns and measure the waveform (timing chart).
CAUTION
Reception mode: VESA 1280 X 1024
H: 80kHz V: 75Hz DOTCLK: 135MHz
WAVE FORM1 : REFCK (LD500)
Frequency: 60MHz
Display screen: Arbitrary
PV/DIV, 10ns/DIV
WAVE FORM2 : XTAL (2pin of the IC601)
Frequency: 14.318MHz
Display screen: Arbitrary
1V/DIV, 50ns/DIV
WAVE FORM3 : VSYNC (LD304)
Frequency: 75Hz
Display screen: Arbitrary
1V/DIV, 5s/DIV
Wave-form No. Measurement point Name of waveform Display pattern
1 LD500 REFCK Arbitrary
2 IC601 of 2PIN XTAL Arbitrary
3 LD304 VSYNC Arbitrary
4 LD303 HSYNC Arbitrary
5 LD510 ICK Arbitrary
6 LD512 VS Arbitrary
7 LD513 IHS Arbitrary
8 IC701 of 10PIN DCLK Arbitrary
9 IC701 of 9PIN DEN Arbitrary
10 LD300, LD301, LD302 RGB OUT 16 monochromatic gradation patterns
Oscilloscope: LeCroy9362
Input signal: VESA1280 X 1024
H: 80kHz V: 75Hz
DOTCLK: 135MHz
GND
GND
GND

PC-UM10M
LL-T1820-H/B WAVE FORM
5 – 2
WAVE FORM4 : HSYNC (LD303)
Frequency: 80kHz
Display screen: Arbitrary
1V/DIV, 5µs/DIV
WAVE FORM5 : ICK (LD510)
Frequency: 67.5MHz
Display screen: Arbitrary
1V/DIV, 5s/DIV
WAVE FORM6 : VS (LD512)
Frequency: 75Hz
Display screen: Arbitrary
1V/DIV, 5s/DIV
WAVE FORM7 : IHS (LD513)
Frequency: 80kHz
Display screen: Arbitrary
1V/DIV, 5µs/DIV
GND
GND
GND
GND