Daewoo L510B1 Schematic

Service Manual

XGA COLOR MONITOR

Model : L510B1

D AEW OO ELECTR ONICS CO., LTD.

SERVICING PRECAUTIONS

◆ General Servicing Precautions

1. Always unplug the AC power cord from the AC power source before: a. Removing or reinstalling any component, circuit board, module, or any other instrument assembly.

b. Disconnecting or reconnecting any electrical plug or other electrical connection. c. Connecting a test substitute in parallel with an electrolytic capacitor in the instrument.

d. Discharging the picture tube anode.

2. Test high voltage only by measuring it with an appropriate high voltage meter or other voltage

measuring device (DVM, FETVOM. etc.) equipped with a suitable high voltage probe. Do not test high voltage by “drawing an arc”.

3. Discharge the picture tube anode only by: (a) first connecting one end of an insulated clip lead to the

degaussing or line grounding system shield at the point where the picture tube socket ground lead is connected, and then (b) touching the other end of the insulated clip lead to the picture tube anode button, using an insulating handle to avoid personal contact with high voltage.

4. Do not any spray chemicals on or near this instrument, or any of its assemblies.

5. Unless otherwise specified in this service manual, only clean electrical contacts by applying the

following mixture to the contacts with a pipe cleaner, cotton-tipped stick, or comparable nonabrasive applicator: 10% (by volume) Aceton and 90% (by volume) isopropyl alchohol (90%-99% strength).

6. Do not apply AC power to this instrument and/or any other of its electrical assemblies unless all the

solid-state device heat sinks are correctly installed.

7. Always connect the test instrument ground lead to the appropriate instrument chassis ground before

connecting the test instrument positive lead. Always remove the test instrument ground lead last.

8. Only use the test fixtures specified in this service manual with this instrument.

CAUTION: Before servicing instruments covered by this service manual, its supplements, and

addendum, please read and follow the SAFETY PRECAUTIONS of this manual.

NOTE: If unforeseen circumstances create conflict between the following servicing precautions and any

of the safety precautions on page 1 of this manual, always follow the safety precautions.

Remember: Safety First.

CAUTION: A wrong part substitution or incorrect polarity installation of electrolytic capacitors

may result in a explosion.

CAUTION: This is a flammable mixture. Unless specified in this service manual, lubrication of

contacts is not required.

◆ Electrostatically Sensitive (ES) Devices

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components are commonly called Electrostatically Sensitive (ES) Devices. The typical examples of ES devices are integrated circuits, some field-effect transistors, and semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, wipe off any electrostatic charge on your body by touching any known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device which should be removed for potential shock reasons prior to applying power to the unit under testing conditions.

2. After removing the electrical assembly equipped with ES devices, place the assembly on a conductive surface such as aluminum foil to prevent electrostatic charge buildup or exposure to the assembly.

3. Only use a grounded-tip soldering iron to solder or unsolder ES devices.

4. Only use an anti-static type solder removal device. Some solder removal devices not classified as “antistatic” can generate enough electrical charges to damage ES devices.

Do not use freon-propelled chemicals. These can generate enough electrical charges to damage ES devices.

6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil, or comparable conductive material).

7. Immediately before removing the protective material from the leads of replacement ES devices, touch the protective material to the chassis or circuit assembly into which the device will be installed.

8. Minimize bodily movements when handling unpackaged replacement ES devices. (Otherwise harmful motion such as the brushing together clothes fabric or the lifting your foot from a carpeted floor can generate enough static electricity to damage ES devices).

◆ General Soldering Guidelines

1. Use a grounded-tip, low-wattage soldering iron with appropriate tip size and shape that will maintain tip temperature between a 550°F-660°F (288°C-316°C) range.

2. Use an appropriate gauge of RMA resin-core solder composed of 60 parts tin/40 parts lead.

3. Keep the soldering iron tip clean.

4. Throughly clean the surface to be soldered. Use a small wire-bristle (0.5 inch or 1.25cm) brush with a metal handle. Do not use freon-propelled spray-on cleaners.

5. Use the following soldering technique: a. Allow the soldering iron tip to reach normal temperature (550°F to 660°F or 288°C to 316°C) b. Hold the soldering iron tip and solder strand against the component lead until the solder melts. c. Quickly move the soldering iron tip to the junction of the component lead and the printed circuit foil,

and hold it there until the solder flows onto and around both the component lead and the foil.

Closely inspect the solder area and remove any excess or splashed solder with a small wire-bristle brush.

CAUTION:

Be sure that no power is applied to the chassis or circuit, and observe all other safety precautions.

CAUTION: Work quickly to avoid overheating the circuit board printed foil.

FIGURE 1. USE SOLDERING IRON TO PRY LEADS

◆ IC Removal/Replacement

Some utilized chassis circuit boards have slotted (oblong) holes through which the IC leads are inserted and then bent flat against the circuit foil. When holes are slotted, the following technique should be used to remove and replace the IC. When working with boards using the familiar round hole, use the standard technique as outlined in paragraphs 5 on the page under the title of general soldering guidelines.

◆ Removal

1. Desolder and straighten each IC lead in one operation by gently prying up on the lead with the soldering iron tip as the solder melts.

2. Draw away the melted solder with an anti-static suction-type solder removal device (or with desoldering braid before removing the IC.

◆ Replacement

1. Carefully insert the replacement IC in the circuit board.

2. Carefully bend each IC lead against the circuit foil pad and solder it.

3. Clean the soldered areas with a small wire-bristle brush. (lt is not necessary to reapply acrylic coating to the area).

◆ “Small-Signal” Discrete Transistor Removal/Replacement

1. Remove the defective transistor by clipping its leads as close as possible to the component body.

2. Bend the ends of each of three leads remaining on the circuit board into a “U” shape.

3. Bend the replacement transistor leads into a “U” shape.

4. Connect the replacement transistor leads to the corresponding leads extending from the circuit board and crimp the “U” with long nose pliers to ensure metal-to-metal contact, then solder each connection.

◆ Power IC, Transistor or Devices Removal/Replacement

1. Heat and remove all solders from the device leads.

2. Remove the heatsink mounting screw (if applicable).

3. Carefully remove the device from the circuit board.

4. Insert new device in circuit board.

5. Solder each device lead and then clip off excess lead.

6. Replace heatsink.

◆ Diode Removal/Replacement

1. Remove defective diode by clipping its leads as close as possible to diode body.

2. Bend the two remaining leads perpendicularly to the circuit board.

3. Observing diode polarity, wrap each lead out of the new diode around the corresponding lead on the circuit board.

4. Securely crimp each connection and solder it.

5. Inspect the solder joints of the two “original” leads on the circuit board copper side. If they are not shiny, reheat them and apply additional solder if necessary.

TECHNICAL INFORMATION

Panel Size 15-inch (38cm) diagonal

Pixel Pitch 0.297 x 0.297mm Viewing Angle 75°(Right/Left)

70°(up), 70°(down) Contrast Ratio 350:1 contrast ratio (typ) Brightness 250cd/m2brightness (typ) Color Filter RGB vertical stripe

Synchronization Horizontal 30 - 62KHz

Vertical 50 - 75Hz

Video Bandwidth 80MHz Max Resolution 1024 x 768 75Hz Colors 6bit (With dithering 16.7M Colors) Display Area 304.1mm x 228.1mm Input Signal Video RGB analog (0.7Vp-p, 75ohms)

Sync H/V separate (TTL)

Input Signal Connector 15 pin mini D-Sub Plug and Play DDC1/2B/CI Power Source 100-240Vac, 50/60Hz (Free Voltage) Power Consumption 25.5W Dimension-W x H x D 390 x 396 x 205mm (with stand)

390 x 325 x 70.5mm (without stand)

Weight(net/gross ) 4.6/6.1Kg

10/13.2lbs

Power Saving EPA, VESA DPMS, Nutek Compliant Tilt/Swivel Range Tilt 5° forward, 30° backward

Swivel 90° leftward, rightward

Operating Temperature 10 ~ 40°C /50 ~ 104°F

This TFT LCD monitor automatically scans all horizontal frequencies from 30KHz to 62KHz, and all vertical frequencies from 50Hz to 75Hz. This TFT LCD monitor supports IBM PC, PC/XT, PC/AT, personal System/2 (PS/2), Apple Macintosh, and compatible users crisp text and vivid color graphics display when using the following graphics adapters : (VGA, Super VGA, VESA and XGA and Apple Macintosh Video Card). And so, this TFT LCD monitor has a maximum horizontal resolution of 1024 dots and a maximum vertical resolution of 768 lines for superior clarity of display.

By accepting analog signal inputs which level is zero to 0.7 Volts. This TFT LCD monitor can display and 262, 144 colors depending on the graphics adapter and software being used. (available used to 8 bit panel is

16.7M colors)

◆ Abbreviations

ADJ Adjustment AFC Automatic Frequency Control TFT-LCD Thin Film Transistor Liquid Crystal Diplay CCFL Cold Cathode Fluorescent Lamp H.SYNC Horizontal Synchronization OSC Oscillator P.S.U Power Supply Unit PWA Printed Circuit Board Wiring Assembly R.G.B Red, Green, Blue V.Sync Vertical Synchronization ADC Analog Display Converter

GENERAL INFORMATION

Arrangement of 15-pin D-sub connector

Pin Signal

1 Red 2 Green 3 Blue 4 GND 5 GND 6 GND - Red 7 GND - Green 8 GND - Blue 9

+5Vdc

10 GND - H.Sync 11 GND - V.Sync 12 Bi-directional Data (SDA) 13 Horizontal Sync 14 Vertical Sync (VCLK) 15 Data Clock (SCL)

610

PIN CONNECTOR

• Degaussing is always required when adjusting purity or convergence.

• The white balance adjustment has been done by a color analyzer in factroy. The adjustment procedure, described in the service manual is made by a visual check.

• Allow 20 minutes warm-up time for the display before checking or adjusting only electrical specification or function.

• Reform the leadwire after any repair work.

◆ Caution For Servicing

•

In case of servicing or replacing inverter, high voltage sometimes remains in the output of the inverter. Completely discharge high voltage before servicing or replacing inverter to prevent a shock to the serviceman.

CAUTIONS FOR ADJUSTMENT AND REPAIR

Control Panel

Hot Key

EXIT

AUTO MENU

BRIGHTNESS

• The AUTO button launches the AUTO TRACKING function directly.

• The EXIT button turns the OSD (On-Screen Display) window off.

• This button moves from sub menu to top menu in the OSD window.

• The MENU button turns the OSD window on.

• This button moves from top menu to sub menu in the OSD window.

•

The button moves cursor to the left or high window in the OSD window.

• This button decreases the value of any selected function.

•

The button moves cursor to the right or low window in the OSD window.

• This button increases the value of any selected function.

AUTO

EXIT

BRIGHTNESS

OPERATION AND ADJUSTMENT

AUTO TRACKING

AUTO BRIGHTNESS

Key Process

OSD OFF

EXIT

OSD

SHARPNESS

UT L TY

Adjustment Procedure

Adjust the CLOCK

control.

Perform the

AUTO

POSITION.

Is the H.Size

proper?

Is the

noise displayed on

the screen?

Perform the

AUTO

TRACKING.

Is the

noise displayed on

the screen yet?

Is the

noise displayed on

the screen yet?

Adjust the

CLOCK FINE

until the screen is

cleared.

Yes

End

+ 21 hidden pages