Sharp LLT155A Schematic

SERVICE MANUAL

LCD COLOR MONITOR

MODEL LL-T155A

CONTENTS

NOTES TO SERVICE PERSONNEL................................................................................. 1

CAUTIONS IN SERVICING............................................................................................... 1

CHAPTER 1: OUTLINE OF THE PRODUCT AND NOMENCLATURE................................. 4

CHAPTER 2: REPLACING LAMPS....................................................................................... 6

CHAPTER 3: CONNECTION, ADJUSTMENT, OPERATION, AND FUNCTIONS................ 8

CHAPTER 4: TROUBLESHOOTING....................................................................................12

CHAPTER 5: TRIMING AND PROCESSING LEAD WIRES................................................14

CHAPTER 6: BLOCK DIAGRAM/UNIT TERMINALS ...........................................................15

CHAPTER 7: APPAEARANCE AND DISASSEMBLY DRAWINGS OF MECHANISMS......17

CHAPTER 8: PACKAGING METHOD..................................................................................18

Parts marked with " " is 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.

This document has been published to be used

SHARP CORPORATION

for after sales service only.
The contents are subject to change without notice.

■Notes to service personnel

·Pictorials

· This servic e manual and th e product us e a variety of pic torials in or der to assure the s afety of repair op erations and of the product

repaired.

· If those pictorials are ignored in repairing, the following troub les might occur:

· Understand the meaning of those pictorials and read this manual carefully before trying to repair the product.

DANDER:
WARNING:
CAUTION:

Failure to follow the instructions in the message might cause a serious accident or death.

Failure to follow the instructions in the message might cause a serious accident or death.

Failure to follow the instructions in the message may cause personal injury or damage to the asset.

·Meaning of symbols ·Pictorial example

symbols mean the necessi t y of using caution.

symbols mean actions wh ich are prohibited.

symbols mean actions to b e required.

■Cautions in servicing

Locations which requi r e a special caution carry safety instructions using labels and stamps on the cabinet, chassis and components.
When servicing, observe t he instructions on such labels and stamps.

Electrical shock Hot surface

Don’t touch Remove power plug

Electrical shock and burn

1. Prior to servicing, make sure to remove the powe r supply plug.

Electrical shock

2. Some parts inside the unit have a high voltage. Use caution to avoid an electrical shock accident when servicing an energized
unit.

Use specified parts

3. The component pa rts of this unit have saf et y characteristics such as flam e resistance and dielectric st rength.

· Use replacement parts which have the same characteristics as those of the components parts used for this unit.

· In particular, component parts marked with in the circuit drawing parts list are important for mainta ining the safety of the

product. Make sure to use specified replacement parts.

Reinstall component parts in their original locations and return wires which have been rerouted for servicing
purposes to their original positions.

4. Some com ponent par ts us e ins ulati ng ma terial s suc h as tu bes or tape f or sa fety pur pose s, or a re mo unted , a bit fl oated , on the
printed wiring bo ard.

· When rerouting inside wiring or clamping the wires, use caution not to bring the wires too close t o heating or high-voltage parts.

· Make sure to return inside wiring to their original locations.

Check for safety after servicing.

5. After finishing servicing, check whether the screws, parts, wires which have been removed for servicing are reinstalled properly.
In addition , chec k to see i f yo u hav e not d eter iorate d par ts a round the pa rt yo u ser vic ed, a nd als o ch eck f or in sulati on be tween
each of the attachment plug terminals and the external metal section.

·Cautions to be taken when making adjustments

WARNING CAUTION

1. Use caution to avoid shorts due to the probe of an
oscilloscope or jigs and do not touch high-voltage
circuits directly.
(There is fear of causing a fire or your getting an
electric short accident)

·Cautions to be taken when replacing electrical parts

WARNING CAUTION

1. Parts marked with are important for
maintaining the safety of the product. Use
specified parts when replacement of such parts is
required. (There is fear of giving off smoke,
catching fire, or your getting an electric shock)

·Cautions to be taken when soldering

WARNING

1. Do not try to solder when th e parts are energized or
the unit is turned on.
(There is fear of causing fire or your getting an
electric shock.)

2. Use caution not to touch heating parts like the
radiating plate directly.
(You could get a burn.)

2. Use caution not to damage the LCD unit when
handling it.

2. Use caution not to damage peripheral parts and
lead wires (e.g., burning peeling o f coating).
(There is fear of causing a fire or your getting an
electric shock accident.)

CAUTION

1. Use caution not to touch a soldering iron directly.
(You could get a burn.)

3. Use caution not to have the wrong direction when
installing parts, if they need the installation of a
correct direction.
(There is fear of causing a fire.)

5. Some parts need to be installed at a specified
intervals or by a specified method for safety
purposes (they may be a bit floated from the board
for dissipating heat.). They mu st be reinstalled to
the original conditions.
(There is fear of causing a fire or your getting an
electrical shock accident.)

2. Make sure the radiating plate or heating parts are
cool enough not to get a burn before touching such
a part.
(You could get a burn.)

4. Use caution to avoid shorts due to an improperly
cut length of parts’ lead legs after soldering and
exercise care not to cut your finger with the edge of
cut surface.
(There is fear of causing a fire or your getting an
injury.

6. Use caution to solder in a correct manner so that
areas other than the part you want to solder are
contaminated with solder, like a solder ball or
bridge.

·Cautions to be taken when disassembling or reassembling the unit

WARNING

1. Prior to servicing, make sure to remove the power
supply plug.
(You could get an electrical shock accident.)

3. Before servicing, make sure you know the locations
of high-voltage p art s.
(You could get an electrical shock accident.)

CAUTION

1. When disassembling or reassembling the unit,
make sure to put the front c abinet side (LCD unit
side) downward and carry out work using caution
not to get your fingers caught.
(Since the LCD unit side is heavier, there is fear of
your getting an injury due to tipping or falling.)

3. When disassembling th e unit, use caution not to get
a burn because r adiating plates and areas around
lamps on the PWB are hot immediately after
unplugging.
(You could get a burn.)

5. Pay attention to burrs or edges of the resin (c ab inet
and PWBs) and metal (chassis and others) parts.
(You could cut your finger with them.)

2. Use caution not to touch the inside of the product
with a wet hand or foot.
(You could get an electrical shock accident.)

4. Do not work on an un stab le plac e or with the stan d
put upright. In particular, fix the cabinet before
replacing PWBs or fan.
(There is fear of your getting an injury due to
tipping or falling.

2. Use caution to avoid a reaction due to your
applying too much force when removing or
reinstalling screws.
(You could get an injury.)

4. Use caution not to get you fingers caught in the
stand pole, between the stand and angles or under
the cabinet.
(You could get an injury.)

6. Use caution to the deformation of the grounding
spring or the displacement of the ferrite core.
(There is fear of causing radio noises to other
equipment.)

·Cautions to be taken when replacing fluorescent lamp

CAUTION

1. Make sure the fluorescent lamp is cool enough not
to get a burn before you are going to touch the
lamp or areas around it .
(You could get a burn.)

3. Use caution not to break the fluorescent lamp when
handling it.
(You could get an injury.)

2. Use caution to avoid a reaction due to your
applying too much force when removing the
connector.
(You could get an injury.)

CHAPTER1. OTLINE OF HE PRODUCT, NOMENCLATURE AND FUNCTIONS

[1] Features

· 38 cm [15 ty pe] 1024-dots x RGB x 7 68-line high-resolu tion TFT

color LCD panel

· 200 cd/m

2

high-luminance d esign

· Connectable to analog RGB output (for CRT)

Multi display mode function that supports resolutions from 640-dot
x RGB x 400-line to up to 1024-dot x RGB x 768-line
In modes l ower than 800 x 600 dots, it is possib le to enlarge the
screen that offers smooth and excellent visibility.
Supports VESA specification, PC9800 series, Power Ma cin tosh.

· Up to 16 million colors can be displayed.

· Automatic screen adjustment

· The display timing and RGB gain can be more finely adjusted due

to the OSD guide functi on, in addition to the automati c adjustment
function.

· Power management fu nction

· Supports Plug&Play (VESA:DDC1, DDC2B specifications)

[2] Safe servicing and safe inspection,

<When servicing or inspecting,
observe the safety instructions.>

1. Observe the cautions.

Locations which require a special caution carry safety instructions
using labels and stamps on the cabinet, chassis and components.
When servicing, observe the instructions on such labels and
stamps as well as those in the Instruction manual.

2. Exercise care not to get an electric al shock
accident.

Some parts have a high voltage inside the unit. Use caution when
handling them while they are energized.

3. Use specified parts.

The component parts of this unit have safety characteristics such
as flame resistance and dielectric strength. Use replacement parts
which have the same characteristics as those of the components
parts used for th is un it. In particular, component parts marked with

in the cir cuit dr awing parts list ar e imp ortant for m aintain ing th e
safety of the product. Make sure to use specified replacement
parts.

5. Check for safety after servicing.

After finishing servicing, check whether the screws, parts, wires
which have be en r em ove d f or serv ic ing a re r ein s talle d p rop erl y. In
addition, check to see if you have not deteriorated parts around th e
part you serviced, and also check for insulation between each of
the attachment plug terminals and the external metal section.

[3] Specifications

1. General specification s

Name of the product: LCD color monitor
Model: LL-T155A, LL-T155B

Item Specifications
LCD display device 38 cm (15 type) TFT color LCD
Picture element pitch 0.297 mm (horizontal) x 0.297 mm (vertical)
Display area 304.1 mm (horizontal) x 228.1 mm (vertical)
Number of picture

elements
Display color approx. 16 million colors (max.)
Input vide signal Analog RGB (0.7 Vp-p/75
Input synchronizing

signal

Input terminal 15-pin mini D-sub connector
USB USB cable relay connector
Plug&Play VESA DDC1/DDC2B
Power management

function
Working temperatu re 5 ~ 35°C
Power supply 100 V AC 50/60 Hz
Power consumption approx. 22 W/ abo ut 3 W in power sav e

Outer dimen sions about 385 mm (width) x 203 mm (depth) x

Weight approx. 6 kg
Accessories AC power supply cord (1), Instruction

1024 x RGB x 768 dots

W )

Horizontal synchronizing sign al TTL level
(positive, negative), vertical synchronizing
signal TTL level (positive, neg ative)

Compatible with VESA DPMS

mode

373 mm (height)

manual (1), warranty (1), adjustment disk
(1), USB cable (1)

4. Reinstall component parts in their original
locations and return wires which have been
rerouted for servicing purposes to their original
positions.

Some component parts use insulating materials such as tubes or
tape for safety purposes, or are mounted, a bit floated, on the
printed wiring bo ard.
When rerouting inside wiring or clamping the wires, use caution not
to bring the wires too close to heati ng or high-voltage pa rts.
Make sure to return inside wiring to their original locations.

· Specifications and a part of the appearance are subject to change

without notice.

2. Technical specifications

Item MIN TYP MAX Unit
Power supply voltage AC 90 100 110 V
Working temperatur e range +5 — +35 °C
Storing temperature range -20 — +60 °C
Humidity range 20 — 85 %RH
Visual angle range Vertical (CR

Horizontal (CR
Contrast ratio(CR) (
Response speed Leading (

Screen white chromaticity (X) 0.283 0.313 0.343 —

White surface lumina nce (Y
Module model number LQ150X1DH10

Specifications and a part of the appearance are subject to change without notice.

q = 0°) 150 — — —

Trailing (

(Y) 0.299 0.329 0.359 —

) 150 200 — cd/m

L

[Power management]

This unit supports VESA*1 DPMS*2.
To use the power management funct ion of this unit, the video card and

the computer must be compatible with the DPMS specifications.

*1 VESA: Video Electronics Standards Association
*2 DPMS:Display Power Management Signaling

5) +20 ~ -50 +35 ~ -60 — Temperature

5) 50 55 — Temperature

t r) — 10 25 ms

t d) — 35 50 ms

2

DPMS mode Screen condition Power consumption Horizontal synchronizati on Vertical synchronization
ONSTATE Displayed state approx. 22 W Yes Yes
STANDBY
SUSPEND Yes No
OFFSTATE No No

No display approx. 3 W

No Yes

[DDC*3]

This unit supports VESA’s DDC specifications
DDC means a signal specification that offers Plug&Play function to the

monitor and the personal computer.
Information about resolution and others are communicated between

the monitor and the personal computer.
This function is available when the personal computer supports DDC.
There are some DDC types depending on different communication

methods.
This unit supports DDC1 and .DDC2B.

*3 DDC: Display Data Channel