JVC LM-15G Service Manual

SERVICE MANUAL

LCD VIDEO MONITOR

LM-15G LM-15G LM-15G

TABLE OF CONTENTS

1. PRECAUTIONS .......................................................................................................................................... 1-3

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

3. DISASSEMBLY ........................................................................................................................................... 1-7

4. ADJUSTEMNT .......................................................................................................................................... 1-12

5. TROUBLE SHOOTING ............................................................................................................................. 1-13

No.52151

2003/7

Items Contents

Type

Dimensions (W × H × D)

Mass

Color system

Scanning frequency

Power Input

Power consumption

LCD Panel

Picture Tube

Display Pixels

Input/Output VIDEO A

terminals

VIDEO B

PC input

REMOTE INPUT

ASPECT

SPECIFICATION

LCD Video Monitor

37cm × 31.1cm × 14.2cm

3.7kg

PAL / NTSC

H : 31.5kHz

V : 56Hz

AC100V/AC240V, 50Hz/60Hz

35W

15-in, active matrix TFT

Visible size : 38cm(Diagonal) / 30.4cm × 22.8cm(H × V)

Hovizontal : 1024 pixel × Vertical : 768 pixel

Composite video, BNC connector ×2, 1V(p-p), 75Ω negative sync

(bridge connection possible, auto termination)

Composite video, BNC connector ×2, 1V(p-p), 75Ω negative sync

(bridge connection possible, auto termination)

Analog RGB : D-sub(16 pin) ×1, positive 0.7 (p-p)

RCA pin ×1

60kHz(PC) / 15.734kHz(NTSC) / 15.625kHz(PAL)

~ 70Hz(PC) / 59.94(NTSC) / 50Hz(PAL)

NOTE: Design & specifications are subject to change without notice.

1-2 (No. 52151)

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 : ( GND, the ISOLATED (NEUTRAL) : ( EARTH : (

) side GND. Don't short between the LIVE

) side GND and

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) If any repair has been made to the chassis, it is

recommended that the B1 setting should be checked or adjusted (See ADJUSTMENT OF B1 POWER SUPPLY).

(6) The high voltage applied to the picture tube must conform

with that specified in Service manual. Excessive high voltage can cause an increase in X-Ray emission, arcing and possible component damage, therefore operation under excessive high voltage conditions should be kept to a minimum, or should be prevented. If severe arcing occurs, remove the AC power immediately and determine the cause by visual inspection (incorrect installation, cracked or melted high voltage harness, poor soldering, etc.). To maintain the proper minimum level of soft X-Ray emission, components in the high voltage circuitry including the picture tube must be the exact replacements or alternatives approved by the manufacturer of the complete product.

) side

(8) 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.

(9) 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 1000 ohms 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 1000Ω/V, OR MORE SENSITIVITY)

0.15µF AC-TYPE

(7) Do not check high voltage by drawing an arc. Use a high

voltage meter or a high voltage probe with a VTVM. Discharge the picture tube before attempting meter connection, by connecting a clip lead to the ground frame and connecting the other end of the lead through a 10kΩ 2W resistor to the anode button.

GOOD EARTH GROUND

1500Ω 10W

PLACE THIS PROBE ON EACH EXPOSED ME TAL PART

(No. 52151) 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. 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.

front side Note

wall

20cm

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.

Use the metal fittings of the exclusive use option.

1.Hang on the wall

2.Hang from the ceiling

3.Put on the table

10cm

front

wall

20cm

10cm

front wall

10cm

front

wall

10cm

front

wall

Install has to be done by professional construction trader

Please confirm the structure and the strength of the wall to install beforehand. It attempts accident prevention and safe securing .

Install on the fixed floor and the stand.

To prevent from an accident and for the safe securing of an earthquake and so on, please process for tumble prevention.

15cm

5cm

15cm

1.2.3 FALL TIP PREVENTION MEASURES

Take precautionary measures to prevent the unit from falling or tipping to protect against emergencies such as earthquakes as well as accidents. Attach the supplied stand to the monitor as shown, and then fix it with the screws. Please fix the stand with the supplied screw (A) first, and then fix it with the screws (B).

1-4 (No. 52151)

10cm

1.3 PRECAUTIONS

(1) Depending on the around temperature, the brightness leaning occurs. Be careful of the environment in the product

installation place and so on sufficiently.

(2) Don't hinder radiation from the back, the heaven and the side. Please refer to the next page that explains about the

condition of the installation.

The inside becomes hot if hindering radiation and there is fear, which the inner circuit damages. (3) Install in the place with good ventilation. Use in the condition that around temperature is in the 0~35°C range. (4) Avoid preservation and use at the high temperature or high humidity place. If you behave like this, leaning sometimes

happens in the screen when the set actives. (5) Depending on the condition and the environment of display, the slight fleck of the light and leaning of the screen and so on

is sometimes conspicuous. This is the characteristic which is peculiar to liquid crystal display. It is not set trouble. (6) This monitor has cool cathode pipe as the backlight. The time change and the use time sometimes change brightness

and condition of display.

1.4 THE ATTENTION IN TRANSPORTATION

When transporting a set, if the load handling is bad (throwing, falling and so on) however it is using a solid box, pressure inside liquid crystal display. In the case there is fear to break the liquid crystal display while transporting. To prevent from the accident or trouble while transporting, pay attention to choice of the transportation company sufficiently and also arrange for it in the delivery after the attention of the load handling is explained to the transportation company. This set is used glass for composing liquid crystal display. When carrying, pay attention not to add over vibration and impact sufficiently.

(No. 52151) 1-5

SECTION 2

SPECIFIC SERVICE INSTRUCTIONS

2.1 DESCRIPTION ABOUT LIQUID CRYSTAL PANEL

2.2.1 STRUCTURE OF LIGUID CRYSTAL PANEL

The Liquid Crystal Panel of this model is TFT Panel. The Print circuit board that consist of TFT array and the print circuit board adopted stripe shaped image element alignment are used. These two boards are mixed. The Liquid crystal is enclosed between two boards.

2.1.2 LONG RANGE AFTERIMAGE OF LIQUID CRYSTAL

The small amount of ion material has mixed a liquid crystal panel with the liquid crystal material in the manufacturing process. If ion material is piled up partially among the poles when the voltage is impressed among the poles, the brightness difference occurs and becomes a long-range afterimage If same picture is reflected for long time, such a long-range afterimage occurs. If the long-range afterimage occurs, we recommend that you reflect the single color image and so on to restore.

2.1.3 THE DISPLAY REPLYING SPEED OF LIQUID CRYSTAL

Because the speed to display of Liquid crystal panel is slower than the speed of the CRT monitor, some of the moving picture cannot overtake to the speed to display and the image looks flowing is sometimes displayed. This is not trouble, but efficiency of Liquid Crystal.

2.1.4 THE EYESIGHT CORNER OF LIQUID CRYSTAL

The liquid crystal panel has the wide eyesight corner for which it is difficult to reverse brightness. The tint changes depending on the direction to see a screen. This is not trouble, but efficiency of Liquid Crystal.

2.1.5 THE PICTURE ELEMENT FAULT OF LIQUID CRYSTAL

The liquid crystal panel is composed of precise technique but all devices don't always work right.

2.2 ATTENTION ITEMS WHEN REPLACING PARTS

2.2.1 ATTENTION TO EXCHANGE THE LIQUID CRYSTAL PANEL

(1) The stillness electricity sometimes makes damage a liquid crystal panel. In liquid crystal panel exchange, do a measure

of the stillness electricity such as the earth band.

(2) A liquid crystal panel and back-light are made from glass. If you gain an impact to these materials, there is fear to damage.

So in case of treatment, be careful sufficiently.

(3) Fix with the screw after confirming that there is not a float to chassis base when exchanging liquid crystal panel.

After that reflect all the black signals and confirm that brightness leaning doesn't occur near the screw fixation part. When brightness leaning occurs, slacken a screw in the neighborhood until the brightness leaning is running-out.

(4) Fix the torque that installs a screw below 0.294Nm.

If you install at any more torque, the liquid crystal panel is transformed and sometimes damages.

(5) If you pull out or insert each connector when power is ON, it causes the trouble.

So pull out or insert each connector in the condition to have pulled out a power supply plug.

2.2.2 ATTENTION WHEN EXCHANGING THE BACK-LIGHT

(1) The back-light is the glass which used cool cathode pipe. In treatment and exchange, pay attention to the following point. (2) Leave the set for a while in the condition that the power is off. Behave the exchanging after lamp's getting cold sufficiently. (3) Adhering the garbage or dust to the luminous part causes brightness leaning Don't touch a part except the lamp folder. (4) The lamp part is fear to break if extra power is gained by the part of the neighborhood of the liquid crystal panel and so on.

Handle the lamp folder and pull out slowly. (5) In installation, insert the lump slowly until the nail of the lamp fixation hangs. (6) Dispose of the exchanged background light according to the local code.

2.2.3 ATTENTION WHEN EXCHANGING THE MAIN PWB

To show the original efficiency of the MAIN PWB, pull out a heat think from the previous MAIN PWB and install it in the new PWB surely.

2.2.4 ATTENTION WHEN EXCHANGING THE FUSE

When exchanging the fuse, please use specified parts. After fuse exchange, confirm that insulater is set to the shield and insulate surely.

1-6 (No. 52151)

SECTION 3

DISASSEMBLY

3.1 DISASSEMBLY PROCEDURE

CAUTION:

• Even with the power switch off, some parts of the unit

are live. Be sure to disconnect the power plug from the AC outlet before disassembly and reassembly.

• Remove the power cord.

3.1.1 REMOVING THE BASE

(1) Lie down the unit and let panel downward. (2) As shown in Fig.1, remove 1 screw [A] and loosen the

two spring screws on BASE.

(3) Slightly remove the BASE.

3.1.2 REMOVING THE FUNCTION COVER

• Remove the BASE.

(1) As shown in Fig.1, remove 5 screws [B]. (2) Shift the FUNCTION COVER toward BASE and raise

upward.

3.1.3 REMOVING THE MAIN PWB

• Remove the FUNCTION COVER.

(1) As shown in Fig.1, remove 4 screws [C]. (2) Slightly remove the MAIN PWB upward.

3.1.4 REMOVING THE POWER PWB

• Remove the FUNCTION COVER.

(1) As shown in Fig.1, remove 4 screws [D]. (2) As shown in Fig.1, remove 1 screw [E], and remove the

earth wire.

(3) Slightly remove the POWER PWB upward.

3.1.9 REMOVING THE CONTROL BRACKET

• Remove the FRONT COVER.

(1) As shown in Fig.1, remove 3 screws [M]. (3) Remove the CONTROL BRACKET upward.

3.1.10 REMOVING THE CONTROL BUTTON

• Remove the CONTROL BRACKET.

(1) As shown in Fig.1, remove 4 screws [N]. (2) Remove two CONTROL BUTTON downward.

3.1.11 REMOVING THE FRONT CONTROL 1 PWB AND THE FRONT CONTROL 2 PWB

• Remove the CONTROL BRACKET.

(1) As shown in Fig.1, remove 2 screws [P]. (2) Remove the FRONT CONTROL 1 PWB upward. (3) As shown in Fig.1, remove 2 screws [Q]. (4) Remove the FRONT CONTROL 2 PWB upward.

3.1.12 REMOVING THE BACK COVER AND THE TERMINAL BRACKET

• Remove the FUNCTION COVER.

• Remove the MAIN PWB

• Remove the POWER PWB

• Remove the INVERTER PWB

• Remove the BNC INPUT PWB

• Remove the FRONT COVER

• Remove the LCD PANEL.

• Remove the CONTROL BRACKET

(1) As shown in Fig.1, remove 4 screws [S]. (2) Remove the BACK COVER and the TERMINAL BRACKET.

3.1.5 REMOVING THE INVERTER PWB

• Remove the FUNCTION COVER.

(1) As shown in Fig.1, remove 3 screws [F]. (2) Slightly remove the INVERTER PWB upward.

3.1.6 REMOVING THE BNC INPUT PWB

• Remove the FUNCTION COVER.

(1) As shown in Fig.1, remove 2 screws [G]. (2) Slightly remove the BNC INPUT PWB upward.

3.1.7 REMOVING THE FRONT COVER

• Remove the BASE.

(1) Lie down the unit and let panel upward. (2) As shown in Fig.1, remove 4 screws [H]. (3) Slightly remove the FRONT COVER.

3.1.8 REMOVING THE LCD PANEL, THELCD BRACKET (R) AND THE LCD BRACKET (L)

• Remove the FRONT COVER.

(1) As shown in Fig.1, remove 4 screws [J]. (2) Raise LCD PANEL upward. (3) As shown in Fig.1, remove 4 screws [K]. (4) Remove the LCD BRACKET (R) and the LCD BRACKET

(L).

(No. 52151) 1-7

TERMINAL BRACKET

POWER PWB

INVERTER PWB

SPRING SCREW

BASE

FUNCTION COVER

BACK COVER

MAIN PWB

EARTH

WIRE

BNC INPUT

PWB

CONTROL BUTTON

LCD BRACKET (R)

LCD PANEL

FRONT CONTROL 1 PWB

1-8 (No. 52151)

LCD BRACKET (L)

CONTROL BUTTON

FRONT CONTROL 2 PWB

CONTROL

BRACKET

FRONT COVER

Fig. 1

3. 2 REPLACEMENT OF MEMORY IC

3.2.1 MEMORY IC

The memory is in the MAIN PWB. The MAIN PWB is only for reference. Avoid replacing individual parts. Replace entire unit only. When the microcomputer or the memory are out of crder, exchange a MAIN PWB.

3. 3 USER SETTING

! PC side

Setting item Setting content Setting value

BACK LIGHT 0 – 100 100

CONTRAST 0 – 100 50

H. POSITION 0 – 100 50

V. POSITION 0 – 100 50

COLOR TEMP.

H. OSD POSITION 0 – 100 50

V. OSD POSITION 0 – 100 50

REMOTE ON/OFF OFF

! Video side (VIDEO A,B)

HIGH,NATURAL,LOW,USER

NATURAL

Setting item Setting content Setting value

BACK LIGHT 0 – 100 100

PICTURE 0 – 100 0

PHASE 0 – 45 23

CHROMA 0 – 100 80

ASPECT 4 : 3, 16 : 9 4 : 3

COLOR TEMP.

LOW LIGHT ADJ. 0 – 255 20

SIGNAL LEVEL STD, AMP STD

H. OSD POSITION 0 – 100 50

V. OSD POSITION 0 – 100 5 0

AGC ON/OFF ON

REMOTE ON/OFF OFF

HIGH,NATURAL,LOW,USER

NATURAL

(No. 52151) 1-9

3.4 REPLACEMENT OF CHIP COMPONENT

3.4.1 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.

3.4.2 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.

3.4.3 REPLACEMENT STEPS

1. How to remove 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 tweezers and remove the chip part.

2. How to install Chip parts

[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 extra solder to each lead.

SOLDER

(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.

[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.

(4) Then solder leads B and C.

1-10 (No. 52151)

SECTION 4

ADJUSTMENT

The service manual does not describe ADJUSTMENT.

(No. 52151) 1-11

SECTION 5

TROUBLE SHOOTING

The service manual does not describe TROUBLE SHOOTING.

1-12 (No. 52151)

VICTOR COMPANY OF JAPAN, LIMITED

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

(No. 52151)

Printed in Japan

WPC

INSTRUCTIONS

LCD VIDEO MONITOR

LM-15G

Thank you for purchasing this JVC LCD video monitor. Before using it, read and follow all instructions carefully to take full advantage of the monitor’s capabilities.

(* “LCD” stands for Liquid Crystal Display.)

For Customer Use:

Enter below the Serial No. which is located on the rear of the cabinet. Retain this

information

for future reference.

Model No. : LM-15G Serial No. :

Contents

Safety Precautions.................................................................................................... 3

Installation.................................................................................................................. 5

Unpacking the Monitor................................................................................................. 5

Controls and Features................................................................................................. 5

Using Y our Monitor .................................................................................................. 7

Turning the Monitor On and Off ................................................................................. 7

Caring for and Cleaning the Monitor .......................................................................... 7

Using the Menu ........................................................................................................ 8

Summary of Control Buttons........................................................................................ 8

Menu Operations......................................................................................................... 8

Using the Monitor in the PC mode............................................................................... 13

Basic Connection Example ..................................................................................... 14

Troubleshooting ....................................................................................................... 15

Specifications.............................................................................................................. 16

+ 34 hidden pages