Daewoo 529B User manual

Service Manual
XGA COLOR MONITOR
Model : 529B
DAEWOO ELECTRONICS CO., LTD
OVERSEAS SERVICE DEPT.

CONTENTS
SAFETY PRECAUTIONS 1
GENERAL SAFETY INFORMATION 2
SERVICING PRECAUTIONS 3
TECHNICAL INFORMATION 6
GENERAL INFORMATION 7
PIN CONNECTOR 8
CAUTIONS FOR ADJUSTMENT AND REPAIR 8
OPERATION AND ADJUSTMENT 9
ALIGNMENT PROCEDURE 13
TROUBLESHOOTING HINTS 15
BLOCK DIAGRAM 29
PCB LAYOUT 30
SCHEMATIC DIAGRAM 33
EXPLODED VIEW & MECHANICAL PARTS LIST 37
INFORMATION OF PART DESCRIPTION 38
ELECTRICAL PARTS LIST 39

1
SAFETY PRECAUTIONS
◆Safety Check
Care should be taken while servicing this analog color display because of the high voltages used in the deflection circuits.
These voltages are exposed in such areas as the associated flyback and yoke circuits.
◆Fire & Shock Hazard
• Insert an isolation transformer between the analog color display and AC power line before servicing the
chassis.
• In servicing, pay attention to the original lead dress, especially in the high voltage circuit; if a short circuit
occurs, replace all parts which have been overheated as a result of the short circuit.
• All the protective devices must be reinstalled per original design.
• Soldering should be inspected for any possible cold solder points, frayed leads, damaged insulation, solder
splashes or sharp solder points. Be certain to remove all foreign materials.
◆Implosion Protection
Picture tubes in this monitor employ an intergral implosion protection system, but care should be taken to
avoid damaging and scratching during installation.
Only use the same type of replacement picture tubes.
◆X-Ray
IMPORTANT SAFETY NOTICE: There are special components used in an analog color display, which
are important for safety. These parts are shaded on the schematic
diagram and on the replacement parts list. It is essential that these
critical parts be replaced with manufacturer’s specified parts to prevent
X-ray, shock, fire, or other hazards. Do not modify the original design
without getting a written permission from DAEWOO
ELECTRONICS CO. or this will void the original parts and labor
warranty.
CAUTION: No modifications of any circuits should be attempted. Service work should only be performed
after you are thoroughly familiar with all of the following safety checks and servicing
guidelines.
WARNING: The only potential source of X-Ray is the picture tube. However, when the high voltage
circuitry is operating properly, there is no possibility of an X-Radiation problem. The basic
precaution that must be exercised is to keep the high voltage at the following factory
recommended level.
NOTE: It is important to use an accurate, periodically-calibrated high voltage meter.
• To measure the high voltage, use a high-impedance high-voltage meter.
Connect(-) to chassis and (+) to the CRT anode button.
• Turn the Contrast & Brightness control fully counterclockwise.
• Measure the high voltage. The high voltage meter should indicate the following factory
recommended levels.
• If the upper meter indication exceeds the maximum level, immediate service is required to
prevent the possibility of premature component failure.
• To prevent the possibility of X-Radiation, it is essential to use the specified picture tube.
• The normal high voltage is 25.5KV or below and must not exceed 29KV level at zero beam
current rated voltage.

2
Warning: This product includes critical mechanical and electrical parts which are essential for x radiation
safety. For continued safety, replace critical components indicated in the service manual only with
exact replacement parts given in the parts list.
The normal operating voltage for this product is 25KV at minimum brightness. Refer to service
manual for measurement procedures and proper service adjustments.
GENERAL SAFETY INFORMATION
◆Terms in the manual
CAUTION Statements identify conditions or practices that could result in damage to the equipment or
other property.
WARNING Statements identify conditions or practices that could result in personal injury or loss of
life.
◆Terms as marked on equipment
CAUTION Statements immediately indicate a personal injury hazard as one reads the marking or a
hazard which is properly included on the equipment itself.
WARNING Statements immediately specify a personal injury hazard as one reads the marking.
◆Symbols in the manual
This symbol indicates where you can find applicable cautionary information.
◆Symbols as marked on equipment
Protective GROUND terminal
◆High Voltage Warning And Critical Component Warning Label
Following warning label is placed on the CRT PWB shield case inside the unit.

3
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. Only test high voltage 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. Only discharge the picture tube anode 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 of any or its assemblies.
5. Unless otherwise specified in this service manual, 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 defeat any plug/socket B+ voltage interlocks with which instruments covered by this service
manual might be equipped.
7. Do not apply AC power to this instrument and/or any of its electrical assemblies unless all solid-state
device heat sinks are correctly installed.
8. 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.
9. 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,
read and closely 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 an explosion and dangerous hazard.
CAUTION: This is a flammable mixture. Unless otherwise specified in this service manual, lubrication of
contacts is not required.
CAUTION: Do not connect the test fixture ground strap to any heatsink in this instrument.

4
◆ Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by static electricity.
Such components commonly are called Electrostatically Sensitive (ES) Devices.
The examples of typical 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,
remove off any electrostatic charge on your body by touching any kind of 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 test.
2. After removing an 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 “anti-
static” can generate enough electrical charges to damage ES devices.
5.
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 a replacement ES device, touch
the protective material to the chassis or circuit assembly into which the device will be installed.
8. Minimize body movements when handling unpackaged replacement ES devices. (Otherwise, harmful
motion such as brushing clothes fabric or the lifting of your foot from a carpeted floor can generate
enough static electricity to damage an ES device).
◆ General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron with appropriate tip size and shape that will maintain
tip temperature within 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.
d.
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.

5
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 end 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.

6
◆ 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 clip off excess lead.
6. Replace heatsink.
◆ Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close as possible to the 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
Electrical
CRT dot pitch 0.28mm dot pitch
Horizontal frequency 30KHz to 70KHz(Automatically)
Vertical fequency 50Hz to 160Hz (Automatically)
Operating temperature 10 - 40°C / 50 - 104°F
Operating humidity 8 - 80%
Mechanical
Cabinet Molded Plastic Cabinet with detachable tilt & swivel base
Dimension (set with stand) 381(H) x 366(W) x 400(D) mm
Weight(net) 12.1 Kg
Controls Power Switch
OSD control
Pincushion, Trapezoid, Pin balance, Parallelogram,
Pin corner top, Pin corner bottom, Rotation, H. center &V. center,
Color Temp, R Gain, B Gain, H. size & V. size, Degauss, Status,
Language, Recall

ADJ Adjustment
AFC Automatic Frequency Control
CRT Cathode Ray Tube
Def Deflection
D.Y Deflection Yoke
FBT Flyback Transformer
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
7
GENERAL INFORMATION
This color monitor automatically scans all horizontal frequencies from 30KHz to 70KHz, and all vertical
frequencies from 50Hz to 160Hz. This color 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, 8514/A, Super VGA, VESA and XGA and Apple
Macintosh Video Card). And so, this color monitor has a maximum horizontal resolution of 1280 dots and
a maximum vertical resolution of 1024 lines for superior clarity of display.
By accepting analog signal inputs which level is zero to 0.7 Volts. This color monitor can display and
unlimited palette of colors depending on the graphics adapter and software being used.
◆ Abbreviations

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)
8
• Degaussing is always required when adjusting purity or convergence.
• The white balance adjustment has been done by a color analyzer in the 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 CRT, high voltage sometimes remains in the anode of the CRT. Completely discharge
high voltage before servicing or replacing CRT to prevent a shock to the serviceman.
Arrangement of 15-pin D-sub connector
PIN CONNECTOR
CAUTIONS FOR ADJUSTMENT AND REPAIR
1
6
15
10

9
OPERATION AND ADJUSTMENT
Control Panel
•Move cursor to the right window on the OSD window.
•Increase the value of any selected function.
•Move cursor to the left window on the OSD window.
•Decrease the value of any selected function.
•Launch OSD(On-Screen Display) MENU window.
•Move cursor to the high window on the OSD window.
•Increase the value of V.size or V.center.
•Move cursor to the low window on the OSD window.
•Decrease the value of V.size or V.center.

10
Key Process
•When you choose the icon on the OSD window, you can exit the OSD screen.
Hot Key
BRIGHTNESS CONTRAST
MENU
Start

11
OSD Functions
Adjust the parallelogram when the screen is leaning left or right.
Adjust the rotation when the screen is tilted left or right.
Adjust the pin corner top when the top sides of the screen are bowed.
ROTATION
PIN CORNER
TOP
PARALLELOGRAM
Adjust the trapezoid of the screen by moving the lines inward or outward.
Adjust the side balance when the sides of the screen are bowed towards left or
right.
PIN BALANCE
TRAPEZOID
Adjust the pin corner bottom when the bottom sides of the screen are bowed.
PIN CORNER
BOTTOM
Adjust the position of the display horizontally(left or right) and vertically (up or
down).
H. CENTER &
V. CENTER
Adjust the width (horizontal size) and the height (vertical size) of the display.
Adjust the blue gain.
BLUE GAIN
H. SIZE &
V. SIZE
Choose different preset color temperatures or set your own customized color
parameters.
COLOR TEMP
RED GAIN Adjust the red gain.
ICON CONTROL FUNCTIONS
Adjust the left and right margins for more convex or more concave margins.
PINCUSHION
Degaussing keeps the monitor free from unwanted magnetism that can result in
color impurity.
DEGAUSS
Display horizontal & vertical frequency and polarity.
STATUS

12
Select language for OSD (5 languages).
LANGUAGE
ICON CONTROL FUNCTIONS
Reset the screen to the Factory Preset Display Settings.
RECALL

13
◆ Standard Adjustment Conditions
1. Power source voltage: 100-240Vac 50/60Hz
2. Aging: Take at least 20 minutes warm/up time.
3. Signals
Video : Analog 0.7Vpp 75Ωterminal positive polarity
Synchronizing : TTL level Negative/Positive Separate/composite
Deflection frequency
Horizontal Frequency : 30KHz - 70KHz
Vertical Frequency : 50Hz - 160Hz
◆ Pre-Adjustment
1. B+ Adjustment
Adjust 185 ± 0.5V DC between P008(TP) and ground at 48KHz mode, varying VR101.
2. H.V. Adjustment
Adjust 106 ± 0.5V DC between P009(TP) and ground at 48KHz mode, varying VR501.
3. H.V. Regulation Adjustment
Adjustment 4.85 ± 0.05V DC between P014 and ground at 48KHz mode, varying VR503.
◆ Main Adjustment
1. Switching to Factory Alignment Mode
Press right and Menu key simultaneously five times, then the OSD controls are switched to factory
mode. If the controls are switched to factory mode, the top line of OSD menu displays at red.
2. Setting the Controls
Set the value of items as following.
Contrast : Max. (OSD value up to MAX)
Brightness : Center (Set the OSD value to center)
3. H.size, V.size, H.phase, V.position, Pincushion, Trapezoid, Parallelogram, Pin balance, Pin corner
Receive the cross hatch pattern of Factory preset mode.
H.size, V.size, H.phase, V.position, Pincushion, Trapezoid, Parallelogram, Pin balance, Pin corner are
adjusted at each mode.
In Factory, Auto Alignment was done at each mode. Therefore, Factory preset mode has it’s
own value according to each control.
4. Focus
(a) Set brightness control to center and contrast control to MAX.
(b) Receive all “H” character pattern of 1280 x1024(64KHz ,60Hz) mode signal.
(c) Adjust the Focus control of FBT to obtain better focus.
5. Geometric Distortion Adjustment.
(a) Receive the cross hatch pattern of 1280 x1024(64KHz ,60Hz) mode signal.
(b) Pincushion, Trapezoid, Parallelogram, Pin balance, Pin corner are adjusted the best geometric
status.
6. White Balance Adjustment
(a) Receive a cross hatch pattern of 68KHz mode signal by using the signal generator.
(b) Set the brightness control to the center, the contrast control to the maximum and sub contrast
control VR to the center.
(c) Cut off the FBT screen VR.
(d) Set the brightness control to the maximum and receive all the black patterns.
(e) Select the R-Bias, G-Bias and B-Bias on the OSD menu and adjust the DATA +/– key to get the
color coordinates in x=0.281, y=0.311 and adjust the FBT screen VR in y=0.5 ~0.8 Ft/L.
(f) Receive a full white pattern.
(g) Select the R-Gain and B-Gain and adjust the DATA +/– key to get the color coordinates in
x=0.281± 0.015, y=0.311±0.015.
ALIGNMENT PROCEDURE

14
(h) Set the brightness control to the center and adjust the sub contrast control to get the screen
luminosity from 33Ft/L.
(i) Check if the x, y coordinates of color analyzer is in x=0.281±0.015, y=0.311±0.015.
If the color coordinates is out of range, adjust the R. G. B BIAS & GAIN to get the coorinates in
x=0.281, y=0.311. Make sure that the coordinates is in range by using contrast control.
7. Static Convergence Adjustment
(a) Apply a magenta cross hatch pattern on display.
(b) Adjust the focus from the best over all focus on the display.
Also adjust the brightness to the desired condition.
(c) Vertical red and blue lines are converged by varying the angle between the two tabs of the 4-pole
magnets.
(d) Horizontal red and blue lines are converged by varying the tabs together keeping the angle between
them constant.
(e) Apply a yellow cross hatch pattern on display.
(f) Vertical green and red lines are converged by varying the the angle between the two tabs of the 6-
pole magnets.
(g) Horizontal green and red lines are converged by varying the tabs together keeping the angle
between them constant.

15
TROUBLESHOOTING HINTS
1. No Character
Are the
Contrast &
Brightness Controls
maximum?
Change the Contrast &
Brightness control value to
maximum
No Raster Refer to
No Raster
Check the peripheral circuit
of CRT
Check the video output
circuit and IC801 (pin 5,7,9)
and their ambient circuit
Trouble in 8Vdc line
of the Main PWB
Check the clamping pulse
circuit
Check the signal cable
No Character
Is whole
screen bright?
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Yes
Yes
Rk, Gk, Bk
About 45Vpp
No
No
Is CRT
Cathode (Rk, Gk, Bk)
signal level
normal?
Is the
output signal of the
(pin 14, 16, 19) pre-amp
IC801, normal?
Is clamping
pulse (pin 12 of IC801)
normal?
Is 12Vdc line
normal?
Is input signal
normal?
Trouble in IC801 and
its ambient circuit
12Vpp

16
2. No Raster
Trouble in
power supply
circuit
Trouble in G1
line of Main PWB
Trouble in FBT
High Voltage
trouble in FBT
Trouble in 65Vdc
line of power
supply unit
Refer to trouble
in P.S.U
Refer to trouble in
power supply unit.
Is CRT
heater red-hot?
No
Yes
No
No
No
No
Yes
No
Yes
Yes
Yes
Yes
No
Is Heater
Voltage (CRT PWB)
about 6V?
Increase the Brightness
& Contrast control level
fully Maximum
No Raster
Is whole
screen bright?
Check
G1 voltage about
-70V?
Is 65Vdc
line normal?
Does
increasing of the
Brightness control level
make screen
bright?
Is CRT
G2 (screen) voltage
about 540V?
Trouble in
CRT
Raster OK
Yes
Trouble in
power supply
circuit

17
3. A Missing Color
Is input signal
normal?
One color is
missing
CRT
Cathode (Rk, Gk, Bk)
is normal?
Is video
output Q801, Q831, Q861
waveform normal?
Each grid (G1, G2)
voltage normal?
Is the
output of
pre-amp IC801
pin 14,16,19 all
normal?
Check video signal
cable or video card
Trouble in IC801 or its
ambient circuit
Trouble in
video output
circuit,
Q803, Q804
Q833, Q834
Q863, Q864
or ambient
Trouble in 65/8Vdc
line
Trouble in G1 line and
G2 line
Replace CRT
No
No
No No
No
Yes
Yes Yes
Yes
Yes
RK, GK, BK
About 45V p-p
0.7Vpp

18
4. Abnormal OSD Font
Is menu key
selected?
Is OSD Font
exist?
One color is
missing
Abnormal OSD Font
Is the
output of IC204
(PIN 13, 14, 15)
normal?
Refer to Missing Color
No
Yes
Yes
Yes
* If menu key selected.
Trouble in
IC801 and its
ambient circuit
No No
Yes
Is
the Fast
Blanking signal
(IC204 pin12)
normal?
Trouble in
Q801,831,861 or its
ambient circuit
Trouble in
IC204 and its
ambient circuit