LG EV700 User manual

COLOR MONITOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS NO. : CA-65
MODEL: EV700, CG771B
ID LABEL: EV700A

CONTENTS
SPECIFICATIONS
- 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
PRINTED CIRCUIT BOARD................................... 26
EXPLODED VIEW...................................................30
REPLACEMENT PARTS LIST ............................... 32
PIN CONFIGURATION........................................... 51
SCHEMATIC DIAGRAM......................................... 58
1. PICTURE TUBE
Size : 17 inch (Flat Square Tube)
DefIection Angle : 90°
Neck Diameter : 29.1mm
Transmission : 52% (TSB: 80%)
Dot Pitch : 0.28mm
Face Treatment : AR-ASC (Anti-Reflection and
Anti-Static Coating)
Low Radiation : TCO-92
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 : R, G, B Analog
4) Signal Format : Refer to the Timing Chart
2-3. Signal Connector
15-pin D-Sub Connector
2-4. Scanning Frequency
Horizontal : 30 ~ 70kHz
Vertical : 50 ~ 160Hz
3. POWER SUPPLY
3-1. Power Range
AC 100~240V (Free Voltage), 50/60Hz, 2.0A Max.
3-2. Power Consumption
4. DISPLAY AREA
4-1. Active Video Area : 315 x 230 mm (12.40" x 9.06")
(Available for Full Screen)
4-2. Display Color : Full Colors
4-3. Display Resolution : 1280 x 1024 / 60Hz
(Non-Interlace)
4-4. Video Bandwidth : 110MHz
5. ENVIRONMENT
5-1. Operating Temperature: 5°C ~ 40°C
(Ambient)
5-2. Relative Humidity : 5% ~ 90%
(Non-condensing)
5-3. Altitude : 10,000ft
6. DIMENSIONS (with TILT/SWIVEL)
Width : 415mm (16.34 inch)
Depth : 459mm (18.07 inch)
Height : 430mm (16.93inch)
7. WEIGHT (with TILT/SWIVEL)
Net Weight : 17.0kg (37.48 lbs.)
Gross Weight : 20.5kg (45.20 lbs.)
MODE
NORMAL (ON)
STAND-BY
SUSPEND
OFF
FAULT
H/V SYNC
ON/ON
OFF/ON
ON/OFF
OFF/OFF
OUT OF RANGE
POWER CONSUMPTION
less than 110 W
less than 15 W
less than 15 W
less than 15 W
less than 3 W
LED COLOR
GREEN
ORANGE
ORANGE
ORANGE

SAFETY PRECAUTIONS
- 3 -
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 Inc. 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 26kV. The following steps describe
how to measure the high voltage and how to prevent
X-radiation.
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.

TIMING CHART
- 4 -
VIDEO
SYNC
C
E
DFA
B
MODE FACTORY PRESET 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
5.720
0.318
3.813
1.589
–
59.940
16.683
15.253
0.922
0.064
0.064
0.794
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
MODE 9
+
68.677
14.561
10.836
3.725
0.508
1.016
2.201
+
84.997
11.765
11.183
0.582
0.015
0.044
0.524
1024
x
768
85Hz
No
MARK
A
B
C
D
E
F
A
B
C
D
E
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
* 1~8 Mode: Preset Mode

OPERATING INSTRUCTIONS
- 5 -
FRONT VIEW REAR VIEW
AC Power Socket Signal Cable
ID Label
Power (DPMS) Indicator Power ON/OFF Button
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 orange.
3. OSD Select/Adjustment
Use this knob for selecting (highlighting) an OSD
icon and adjusting level of the selected menu.
Front Control Panel
2. Power (DPMS) Indicator 3. OSD Select/Adjustment 1. Power ON/OFF Button

- 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.
800 x 600
H : 68.4 kHz V : 84.6 Hz
EXIT
OSD R
USER MORE
SELECT
:
NAVIGATE
:
HORIZONTAL
SIZE
800 x 600
H : 68.4 kHz V : 84.6 Hz
EXIT
OSD R
USER MORE
SELECT
:
ADJUST
:
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.
Moiré: To reduce moiré.
Moiréis caused by intreference the periodical
display pattern with the periodical dot screen.
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 four 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.
MONITOR SELF TEST
YOUR MONITOR IS
WORKING CORRECTLY
CHECK COMPUTER POWER
AND MONITOR CABLE
OUT OF FREQUENCY
HF : 120.0kHz
VF : 110.0Hz
HF : 30-70kHz
VF : 50-160Hz
OPERATING FREQUENCY

- 7 -
CONTROL LOCATIONS
MAIN
CONTROL
FBT
34
5
2
1
No.
1
2
3
No.
4
5
Ref. No.
SW201
VR201
VR101
Ref. No.
VR701
VR901
Control Function
POWER SWITCH
OSD SELECT/ADJUSTMENT
TCO ADJUSTMENT
Control Function
HIGHT-VOLTAGE ADJUSTMENT
B+ADJUSTMENT

WIRING DIAGRAM
- 8 -
P201
P401 P102
P101
P501
P301P302
P702
P402
P902 P903
S+
S
P304
P303
P703
Signal
Cable
AC
Socket
FBT
CONTROL

DISASSEMBLY
- 9 -
1. TILT/SWIVEL REMOVAL
1) Set the monitor face downward.
2) Pressing the latch (a), carefully remove the
Tilt/Swivel by pulling it upward.
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.
P301
P304
P302
(a)
(a)
(b)
(a)
(a)
(a)
4. VIDEO PCB ASSEMBLY REMOVAL
1)
Disconnect P301, P302, P304 from the Video PCB.
2) Remove two screws (a) from the Total Chassis
Assembly.
3) Remove the Total Chassis Assembly.
(a)
(a)
3. TOTAL CHASSIS ASSEMBLY REMOVAL
1) Disconnect P902 (Degaussing pin), P701, P601
(DY pin), and P501(Tilt pin).
2) Remove two screws (a) from the Total Chassis
Assembly.
3) Remove the Total Chassis Assembly.

- 10 -
5. BOTTOM BRACKET REMOVAL
1) Remove three screws (a).
2) Remove four screws (b).
3) Remove the Bottom Bracket.
6. MAIN BOARD ASSEMBLY REMOVAL
1) Remove three screws (a).
2) Remove three screws (b).
3) Release two latches (c) from the Main Board
Assembly.
(b)
(a)
(b)
(b)
(c)
(c)
(a)
Bottom Bracket