Gateway CG572E, EV500 Service Manual

COLOR MONIT OR

SER VICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS NO. : CA-85

MODEL: CG572E, EV500

ID LABEL: EV500B

*NEW MODEL

Issue Date: AUGUST 2000.

1. PICTURE TUBE

Size : 15 inch (Flat Square Tube)
DefIection Angle : 90°
Neck Diameter : 29.1 mm
Dot Pitch : 0.28 mm
Face Treatment : AR-ASC (Anti-Reflection and

Anti-Static Coating)

Low Radiation : MPR-II, TCO99

(유럽향)

2. SIGNAL

2-1. Horizontal & Vertical Sync

1) Input Voltage Level: Low=0~1.2V, High=2.5~5.5V

2) Sync Polarity : Positive or Negative

2-2. Video Input Signal

1) Voltage Level : 0 ~ 0.7 Vp-p
a) Color 0, 0 : 0 Vp-p
b) Color 7, 0 : 0.467 Vp-p
c) Color 15, 0 : 0.7 Vp-p

2) Input Impedance : 75 Ω

3) Video Color : RGB Analog

4) Signal Format : Refer to the Timing Chart

2-3. Signal Connector

15-pin (D-SUB/3 RAW)

2-4. Scanning Frequency

Horizontal : 30 ~ 70 kHz
Vertical : 50 ~ 160 Hz

3. POWER SUPPLY

3-1. Power Range

AC 100~240V (Free Voltage), 50/60Hz, 1.5A Max.

3-2. Power Consumption

4. DISPLAY AREA

4-1. Active Video Area :

• Max Image Size - 285 x 215 mm (11.22" x 8.46")

• Preset Image Size - 270 x 200 mm (10.63" x 7.87")
4-2. Display Color : Full Colors
4-3. Display Resolution : 1280 x 1024 / 60Hz

(Non-Interlace)

4-4. Video Bandwidth : 110 MHz

5. ENVIRONMENT

5-1. Operating Temperature: 5°C ~ 40°C (41°F ~ 104°F)

(Ambient)

5-2. Relative Humidity : 5%~ 90%

(Non-condensing)

5-3. Altitude : 10,000 ft

6. DIMENSIONS (with TILT/SWIVEL)

Width : 371.5 mm (14.62 inch)
Depth : 401.5 mm (15.80 inch)
Height : 425 mm (16.73 inch)

7. WEIGHT (with TILT/SWIVEL)

Net Weight : 14.0 kg (30.86 lbs.)
Gross Weight : 16.5 kg (36.38 lbs.)

CONTENTS

- 2 -

SPECIFICATIONS ................................................... 2

SAFETY PRECAUTIONS ........................................ 3

TIMING CHART ....................................................... 4

OPERATING INSTRUCTIONS ................................ 5

CONTROL LOCATIONS ......................................... 7

WIRING DIAGRAM ................................................. 8

DISASSEMBLY ....................................................... 9

BLOCK DIAGRAM ................................................. 11

DESCRIPTION OF BLOCK DIAGRAM...................12

ADJUSTMENT ...................................................... 14

TROUBLESHOOTING GUIDE .............................. 16

EXPLODED VIEW...................................................26

REPLACEMENT PARTS LIST ............................... 28

PIN CONFIGURATION........................................... 37

SCHEMATIC DIAGRAM......................................... 41

PRINTED CIRCUIT BOARD................................... 43

SPECIFICATIONS

MODE

NORMAL

STAND-BY

SUSPEND

OFF

POWER CONSUMPTION

less than 95 W
less than 15 W
less than 15 W
less than 3 W

LED COLOR

GREEN

AMBER

SAFETY-RELATED COMPONENT WARNING!

There are special components used in this color monitor
which are important for safety. These parts are marked

on the schematic diagram and the replacement

parts list. It is essential that these critical parts should be

replaced with the manufacturer's specified parts to
prevent X-radiation, shock, fire, or other hazards. Do not
modify the original design without obtaining written
permission from GATEWAY or you will void the original
parts and labor guarantee.

CAUTION:

No modification of any circuit should be
attempted.
Service work should be performed only after
you are thoroughly familiar with all of the
following safety checks and servicing
guidelines.

SAFETY CHECK

Care should be taken while servicing this color monitor
because of the high voltage used in the deflection circuits.
These voltages are exposed in such areas as the
associated flyback and yoke circuits.

FIRE & SHOCK HAZARD

An isolation transformer must be inserted between the

color monitor and AC power line before servicing the
chassis.

• In servicing, attention must be paid to the original lead
dress specially in the high voltage circuit. If a short
circuit is found, replace all parts which have been
overheated as a result of the short circuit.

• All the protective devices must be reinstalled per the
original design.

• Soldering must be inspected for the cold solder joints,
frayed leads, damaged insulation, solder splashes, or
the sharp points. Be sure to remove all foreign
materials.

IMPLOSION PROTECTION

All used display tubes are equipped with an integral
implosion protection system, but care should be taken to
avoid damage and scratching during installation. Use only
same type display tubes.

X-RADIATION

The only potential source of X-radiation 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 which must be exercised is keep the
high voltage at the factory recommended level; the normal
high voltage is about 24.5kV. The following steps describe
how to measure the high voltage and how to prevent X­radiation.

Note : It is important to use an accurate high voltage

meter calibrated periodically.

• To measure the high voltage, use a high impedance
high voltage meter, connect (–) to chassis and (+) to
the CDT anode cap.

• Set the brightness control to maximum point at full
white pattern.

• Measure the high voltage. The high voltage meter
should be indicated at the factory recommended level.

• If the meter indication exceeds the maximum level,
immediate service is required to prevent the possibility
of premature component failure.

• To prevent X-radiation possibility, it is essential to use
the specified picture tube.

CAUTION:

Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.

SAFETY PRECAUTIONS

- 3 -

TIMING CHART

- 4 -

VIDEO

SYNC

C

E

D

F

AB

MODE

Resolution

Recall

H
O
R

I
Z
O
N
T
A
L

V
E

R

T

I
C
A

L

kHz

µs
µs
µs
µs
µs
µs

Hz
ms
ms
ms
ms
ms
ms

MODE 2

—

37.500

26.667

20.317

6.349

0.508

2.032

3.810

—

75.000

13.333

12.800

0.533

0.027

0.080

0.427

640

x

480

75Hz

Yes

MODE 1

—

31.469

31.778

25.422

6.356

0.636

3.813

1.907

—

59.940

16.683

15.253

1.430

0.318

0.064

1.048

640

x

480

60Hz

Yes

MODE 3

—

31.470

31.776

25.421

6.355

0.636

3.813

1.907
+

70.000

14.269

12.712

1.557

0.382

0.063

1.112

720

x

400

70Hz

Yes

MODE 4

+

37.879

26.400

20.000

6.400

1.000

3.200

2.200
+

60.317

16.579

15.840

0.739

0.026

0.106

0.607

800

x

600

60Hz

Yes

MODE 5

+

46.875

21.333

16.162

5.172

0.323

1.616

3.232
+

75.000

13.333

12.800

0.533

0.021

0.064

0.448

800

x

600

75Hz

Yes

MODE 6

—

48.363

20.677

15.754

4.923

0.369

2.092

2.462

—

60.004

16.666

15.880

0.786

0.062

0.124

0.600

1024

x

768

60Hz

Yes

MODE 7

+

60.023

16.660

13.003

3.657

0.203

1.219

2.235
+

75.029

13.328

12.795

0.533

0.017

0.050

0.466

1024

x

768

75Hz

Yes

MODE 8

+

63.981

15.630

11.852

3.778

0.444

1.037

2.296
+

60.020

16.661

16.005

0.656

0.016

0.047

0.594

1280

x

1024

60Hz

Yes

MARK

E
A
B
C

D
F

E
A
B
C

D
F

Sync Polarity

Frequency

Total Period

Video Active Time

Blanking Time

Front Porch

Sync Duration

Back Porch

Sync Polarity

Frequency

Total Period

Video Active Time

Blanking Time

Front Porch

Sync Duration

Back Porch

FACTORY PRESET MODE

* Mode 1~Mode 8: PRESET Mode

Gateway

EV500

- 5 -

OPERATING INSTRUCTIONS

Gateway

EV500

FRONT VIEW REAR VIEW

AC Power Socket

Signal Cable

Power ON/OFF Button

Power (DPMS) Indicator

1. Power ON/OFF Button

This button is used to turn the monitor ON and OFF.

2. Power (DPMS) Indicator

This indicator lights up green when the monitor
operates normally; in DPMS (Energy Saving) mode,
– stand-by, suspend, or off mode – its color changes
to amber.

3. OSD Select/Adjustment

Use this knob for selecting (highlighting) an OSD
icon and adjusting level of the selected menu.

Front Control Panel

3. OSD Select/Adjustment

1. Power ON/OFF Button2. Power (DPMS) Indicator

- 6 -

On Screen Display (OSD) Control

To adjust an image size, position, and operating
parameters are quick and easy with the On Screen Display
control system, using the OSD Select/Adjustment

knob.

A
quick example is given below to familiarize yourself with
use of the controls.

Example;

Note: (Monitor and PC’s power switch should be ON,
with an image or prompt on the screen). A single
press of the OSD Select/Adjustment knob will present
you the main menu as below:

To adjust this item, rotate the OSD Select/Adjustment
knob and push it at the point of the selected item.
The display will look like as below:

Listed below are icons, icon names.

Pincushion:

To correct bowing in or out of the image.

Tilt: To correct the image rotation.
Parallelogram: To correct the geometric distortion.
Pincushion Balance:

To correct balance on each side distortion.

Horizontal Moiré
Vertical Moiré

Trapezoid:

To correct the geometric distortion.

Degauss: Used to demagnetize the picture to give

a more accurate image and color.

Mode Recall: To recall factory preset mode.

R

Advanced Option: There are five kinds of options.

MORE

Color Select: To select color temperature or set

color level; 9300K / 6550K / USER.

Exit:

To make the OSD disappear on the screen.

Language Select:

To choose one of the five languages for the OSD menu.

EXIT

Information: There is information of video

modes-preset and user modes.

USER

OSD

OSD Manager: To adjust horizontal or vertical

position of the OSD image.

Icon Description

Horizontal Size: To adjust the image width.
Horizontal Position:

To move the image left or right.

Vertical Size : To adjust the image height.
Vertical Position: To move the image up or down.

Contrast: To adjust the image contrast level.
Brightness:

To adjust the screen brightness level.

Icon Description

Out of Frequency Range

When inputed video signal is not available, the message will
display as below:

Self Diagnosis

This monitor has a SELF DIAGNOSIS OSD feature that is
pops up when the signal cable is not connection between a
PC and a monitor. The message will be highlighted as
below.

OUT OF FREQUENCY

HF : 120.0kHz
VF : 110.0Hz

HF : 30-70kHz
VF : 50-160Hz

OPERATING FREQUENCY

:To reduce moiré.

Moiré is caused by intreference
the periodical display pattern
with the periodical dot screen.

H : 46.8 kHz V : 75 Hz

EXIT

800 x 600

HORIZONTAL

OSD

USER

:

NAVIGATE

SIZE

R

MORE

:

SELECT

H : 46.8 kHz V : 75 Hz

800 x 600

EXIT

OSD

USER

:

ADJUST

MORE

:

SELECT

R

MONITOR SELF TEST

YOUR MONITOR IS

WORKING CORRECTLY

CHECK COMPUTER POWER

AND MONITOR CABLE

CONTROL LOCATIONS

- 7 -

MAIN

FBT

CONTROL

12

NO.1Ref. No.

SW201

NO.

2

Ref. No.

VR201

Control Function

POWER BUTTON

Control Function

OSD SELECT/ADJUSTMENT

WIRING DIAGRAM

- 8 -

P201

P401

P501

W1

W3

P301

P302

P702

P402

P902

S

+

S

CDT

EARTH

P1

Signal
Cable

AC
Socket

FBT

DISASSEMBLY

- 9 -

2. BACK COVER REMOVAL

1) Remove two screw caps (a).

2) Remove four screws (b).

3) Slide the Back Cover away from the Front
Cabinet of the monitor.

(a)

1. TILT/SWIVEL REMOVAL

1) Set the monitor face downward.

2) Pressing the latch (a), carefully remove
the Tilt/Swivel by pulling it upward.

DY Pin

P201

Degaussing
Coil

DY Assembly Screw

P401

P501

P402

P701

P2

Tilt coil

Anode Cap

P902

3. TOTAL CHASSIS ASSEMBLY REMOVAL

1)

Remove connector (a) from the DY Assembly screw.

2) Disconnect P2(CDT EATH) and four pins (b)
from the Video PCB.

3) Carefully separate the CDT Board Assembly
from the CDT neck.

4) Discharge the remaining static electricity
by shorting between the Anode Cap
and the CDT ground.

5) Disconnect the Anode Cap
from the CDT.

6) Disconnect P902
(Degaussing pin),

P701(DY pin), and
P501 from the Main PCB.

7) Remove four screws (c).

8) Remove the Total Chassis
Assembly from the Cabinet.

(a)

(a)

(a)

(b)

(b)

(b)

(b)

(C)

(C)

(C)

(C)

- 10 -

4. CONTROL PCB ASSEMBLY REMOVAL

1) Remove three screws (a).

2) Remove the Control PCB Assembly
from the Front Cabinet.

5. VIDEO PCB ASSEMBLY REMOVAL

1) Disconnect P301, P302, P1 from the Video
PCB.

2) Remove three screws (a).

3) Remove two screws (b).

3) Remove the Video PCB Assembly from the
Main total Ass’y

(a)

(a)

(a)

(b)

(a)

6. BOTTOM BRACKET REMOVAL

1) Remove eight screws (a).

2) Remove the Bottom Bracket.

(a)

P301

P1

P302

P702

BLOCK DIAGRAM

- 11 -

AC 90~264V INPUT

Line

Filter

Degaussing

Circuit

SMPS

TRANS

(T901)

SMPS

CONTROL

(IC901)

DPM

CONTROL

CIRCUIT

5V

Regulator

105V

50V 15V

6.3V

-12V

TILT

Control

Circuit

6.3V

15V

E

2

PROM

(IC402)

5V

OSD IC

(IC301)

H-Sync Sig

V-Sync Sig

I

2

C DATA(SDA)

I

2

C CLOCK(SCL)

VIDEO

PRE-AMP

(IC302)

Signal

Cable

R

G

B

VIDEO

MAIN AMP

(IC303)

5V

5V

H/V Sync Processor

( IC701 )

TDA9113

V-OUT

( IC601)

TDA8172

H-OUT

( Q706)

H-Linearity

Correction

Screen Control

Circuit

DC/DC Converter

X-RAY

Protection

Circuit

FBT

( T701 )

Auto

Beam

Limit

Vertical Blanking,

Brightness Control

- 120V

40V

600V

15V

D/D Feed Back

15V

MICOM

(IC401)

SCL / SDA

H/V Sync,

PWM Control

12V

6.3V

15V

105V

15V

50V

DY CDT

Heater ( 6.3V )

I

2

C

I

2

C

I

2

C

H/V

Sync

G

1

Screen

Focus

H.V

R/G/B

Drive/Contrast

Cut-Off

H-DRV

B-DRV

B+

15V

TILT

COIL

DEGAUSSING

COIL

I

2

C

Vout

.CONTRAST

.BRIGHTNESS

.H-SIZE

.H-POSITION

.V-SIZE

.V-POSITION

.PINCUSHION

.TRAPEZOID

.DEGAUSS

.RECALL

.ADVANCED OPTION

.COLOR

.LANGUAGE

.INFORMATION

.OSD MANAGER

.EXIT

<OSD DISPLAY>

DESCRIPTION OF BLOCK DIAGRAM

- 12 -

1. Line Filter & Associated Circuit.

This is used for suppressing noise of power input line
flowing into the monitor and/or some noise generated in
this monitor flowing out through the power input line.
That is to say, this circuit prevents interference between
the monitor and other electric appliances.

2. Degauss Circuit & Coil.

The degauss circuit consists of the degaussing coil, the
PTC(Positive Temperature Coefficient) thermistor(TH901),
and the relay(RL901). This circuit eliminates abnormal
color of the screen automatically by degaussing the
shadow mask in the CRT during turning on the power
switch. When you need to degauss in using the monitor,
select DEGAUSS on the OSD menu.

3. SMPS(Switching Mode Power Supply).

This circuit is working of 90~264V AC(50/60Hz).
The operation procedure is as follows:

1) AC input voltage is rectified and smoothed by the
bridge diodes (D901~D904) and the capacitor (C908).

2) The rectified voltage(DC) is applied to the primary
coil of the transformer(T901).

3) The control IC(IC901) generates switching pulse to
turn on and off the primary coil of the transformer
(T901) repeatedly.

4) Depending on turn ratio of the transformer, the
secondary voltages appear at the secondary coils of
the transformer(T901).

5) These secondary voltages are rectified by each
diode(D941, D951, D961, D971, D953) and operate
other circuit. (horizontal and vertical deflection, video
amplifier, ...etc.)

4. X-ray Protection.

I

f the high voltage of the FBT reaches up to 29kV (abnormal
state), Q807 operates and IC401(MICOM) pin 41 come to
low level. Then MICOM control IC701 (Deflection controller)
to stop Horizontal drive pulse and stop Horizontal Deflection.

5. Micom(Microprocessor) Circuit.

The operating procedure of Micom(Microprocessor) and its
associated circuit is as follows:

1) H and V sync signal is supplied from the signal cable.

2) The Micom(IC401) distinguishes polarity and
frequency of H and V sync.

3) The Micom sets operating mode and offers the
controlled data. (H-size, H-position, V-size, ... etc.)

4) The controlled data of each mode is stored in itself.

5) User can adjust screen condition by each OSD
function. The data of the adjusted condition is stored
in EEPROM(IC402).

6. Horizontal and Vertical Oscillation.

This circuit generates the horizontal pulse and the vertical
pulse by taking the H and V sync signal.
This circuit consists of the TDA9113(IC701) and the
associated circuit.

7. D/D(DC to DC) Converter.

This circuit supplies DC voltage to the horizontal deflection
output circuit by increasing DC 50V which is the
secondary voltage of the SMPS in accordance with the
input horizontal sync signal.

8. Side-Pincushion & Trapezoid Correction Cirucit.

This circuit improves the side-pincushion and the
trapezoid distortion of the screen by mixing parabola and
saw-tooth wave to output of the horizontal deflection D/D
converter which is used for the supply voltage(B+) of the
deflection circuit.

9. Horizontal Deflection Output Circuit.

This circuit makes the horizontal deflection by supplying
the saw-tooth current to the horizontal deflection yoke.

10. High Voltage Output & FBT(Flyback Transformer).

The high voltage output circuit is used for generating pulse
to the primary coil of the FBT(Flyback Transformer
(T701)). A boosted voltage(about 24.5kV) appears at the
secondary of the FBT and it is supplied to the anode,
focus, and screen voltage of the CRT.

11. H-Linearity Correction Circuit.

This circuit corrects the horizontal linearity for each
horizontal sync frequency.

12. Vertical Output Circuit.

This circuit takes the vertical ramp wave from the
TDA9113(IC701) and performs the vertical deflection by
supplying the saw-tooth current to the vertical deflection
yoke.

13. H& V Blanking and Brightness Control.

Blanking circuit eliminates retrace line by supplying
negative pulse to the G1 of the CRT. And Brightness
circuit is used for control of the screen brightness by
changing DC level of the G1.

14. Image Rotation (Tilt) Circuit.

This circuit corrects the tilt of the screen by supplying the
image rotation signal to the tilt coil which is attached near
the deflection yoke of the CRT.

- 13 -

15. Video Pre-Amp Circuit.

This circuit amplifies the analog video signal from 0-0.7V
to 0-4V. It is operated by taking the clamp, R, G, B drive
and contrast signal from the Micom(IC401).

16. Video Output Amp Circuit.

This circuit amplifies the video signal which comes from
the video pre-amp circuit and amplified it to applied the
CRT cathode.