Kortek KT-2914F, KT-2914DF, KT-2114F, KT-2114DF Service Manual

SERVICE MANUAL

COLOR CRT MONITOR

KT-2914F / KT-2914DF
KT-2114F / KT-2114DF

KORTEK CORPORATION

DOC. NO KT-XX14X-SM

DATE 2004 .02. 02

REV. NO 0

REV. DAT E -

- 2 -

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

2. PRODUCT SPECIFICATION -------------------------------- 6

3. OPERATING INSTRUCTION -------------------------------- 9

4. ADJUSTMENTS ------------------------------------------------ 11

5. TROUBLE SHOOTING GUIDE ---------------------------- 19

6. PART LIST ------------------------------------------------------- 29

7. BLOCK DIAGRAM -------------------------------------------- 34

8. CONNECTING DIAGRAM ----------------------------------- 35

9. SCHEMATIC ----------------------------------------------------- 36

10. PRINT CIRCUIT BOARD ---------------------------------- 37

CONTENTS

- 3 -

1-1. Safety precautions

Warnings :

Service should not be attempted by anyo ne unfamiliar with the

necessary on this Monitor.

The followings are the necessary precautions to be observed before servicing.

1) For continued safety, do not attempt to modify the circuit board.

2) Disconnect the AC power before servicing.

3) When the chassis is operating, semiconductor heat sinks are potential
shock hazards.

1-1-1 Servicing the high voltage volume are CRT Warnings

A High Voltage volum e replaced in the wrong direction may cause excessive

X-Ray emissions.

1) Adjust in order to 26KV with signal at Anode.

2) When the troubleshooting a monitor with excessively High Voltage, avoid
being unnecessarily close to the monitor. Do not operate the monitor for
longer than is necessary to locate the cause of excessive voltage.

3) Excessive High Voltage can produce potentially hazardous X-Ray RADIA­TION. To avoid such hazards, the high voltage m ust be above the
specified lim it. The nominal value of the High voltage of this Monitor is
26KV±0.3KV at zero beam current(m inimum brightness) under a 120V
AC power source. The High Voltage must not (under any circum stances)
exceed 29KV. Each tim e a monitor requires servicing, the High Voltage
should be checked following the High Voltage check procedure on this
manual. It is recommended the reading of the voltage be recorded as a
part of the service record. It is im portant to use an accurate and reliable
High Voltage meter.

4) When the High Voltage regulator is operating properly, there is no possib­ility of an X-Ray problem.

5) The CRT is especially designed to prohibit X-ray emission. To ensure
continued X-ray protection, replace the CRT only with one that is the
sam e or equivalent type as the original.

6) Handle the CRT only when wearing shatterproof goggles and after completely.

7) Do not lift the CRT by the neck.

1.Precautions

- 4 -

1-1-2. Fire and Shock Hazard

Before returning the monitor to the user,perform the following safety checks:

1) Inspect each lead dress to make certain that the leads are not pinched or
that hardware is not lodged between the chassis and other metal parts
in the monitor.

2) Inspect all protective devices such as nonm etallic control knobs, insulating
materials, cabinet backs, adjustment and com partment cover or shields
isolation resistor-capacitor networks, m echanical insulations, etc.

3) To be sure that no shock hazard exists, check for leakage current in the
following manner.
a. Plug the AC line cord directly into a 120 or 230 Volt AC outlet.

(Do not use an isolation transformer for this test)

b. Using two clip leads, connect a 1.5KΩ, 10Watt resistor paralleled by a

0.15Uf capacitor in serial with an exposed metal chassis part and a
known earth ground, such as an electrical conductor and electrical
ground connected to a earth ground.

c. Use a SSVM or VOM with 1000 ohms per-volt or sensitivity to measure

the AC voltage drop across the resistor.

d. Connect the resistor to an exposed metal part having a return path to

the chassis(m etal cabinet, screw heads, knobs, shafts, escutcheon,etc)
and measure the AC voltage drop across the resistor.

e. Any reading of 5.25 volt RMS(this corresponds to 3.5 milliampere AC)

or more is excessive and indicates a potential shock hazard. Correct
the shock hazard before returning the monitor to the user.

Figure 1-1. Leakage Current Test Circuit

LEAKAGE
CURRENT
TESTER

(READING SHOULD)

NOT BE ABOVE

0.5m A

TEST AL L

EXPOSED METAL

SURFACES

DEVICE
UNDER

TEST

2-WIRE
CORD

ALSO TEST WITH

PLUG REVERSED
(USING AC ADAPTER
PLUG AS REQUIRED)

Earth
ground

- 5 -

1-1-3. Product safety notices:

Some electrical and mechanical parts have special safety related characteristics
which are often not evident from visual inspection. The protection they give
may not be obtained by replacing them with components rated for higher volt­age,wattage,etc. Parts that have special safety characteristics are identified by

△

on schematics and parts lists.
A substitute replacement that does not have the sam e safety characteristics
as the recommended replacement part might create shock, fire and or other
hazards. Product safety is under review continuously and new instructions
whenever appropriate.

1-2. Servicing Precautions

WARNING 1 : First read the "Safety Precaution" section of this manual. if

unfo reseen circumstances create conflict between the servicing
precautions and safety precautions,always fo llow the safety
precautions.

WARNING 2 : A High Voltag e volume replaced in the wrong direction may

cause excessive X-ray emissions.

WARNING 3 : An electrolytic capacitor in stalled with the wrong polarity might

explode.

1) Servicing precautions are printed on the chassis, and should be followed
closely

2) Always unplug the units AC power cord from the AC power source before
attempting to :(a) remove or reinstall any component or assem bly, (b)
disconnect PCB plugs or connectors,(c) connect all test com ponents in
parallel with an electrolytic capacitor.

3) after servicing, always check that the screws, components and wiring have
been correctly reinstalled. Make sure that the area around the serviced
part has not been dam aged.

4) Check the insulation between the blades of the AC plug and accessible
conductive parts(examples:m etal panels,input terminals and earphone jacks).

5) Never defeat any of the +B voltage interlocks. Do not apply AC power to
the unit(or any of its assemblies) unless all solid-state heat sinks are
correctly installed.

6) Always connect a test instruments ground lead to the instrum ent chassis
ground before connecting the lead; always remove the instruments lead last.

- 6 -

2-1 SPECIFICATION

CDT

Display Area (mm)

Bandwidth Maximum 50MHz
Scanning Frequency

(Auto Scanning)

Horizontal
Vertical

15-40KHz
50-120Hz

Microprocessor User Saving Mode 6 Modes

User Control
Display

Digital

Language

Position,Size,Pincushion,T rapezoid,H/Vcorner,
Pin-B,Trapezoid,Parallel,Tilt,Moire,Zoom
Color T emperature,Recall,Manual Degauss
Eng/Ger/F ra/Esp/Port

Display color Color T emperature 9300°K, 6500°K, User Color
Resolution Maximum M ode 800 X 600 @ 60Hz
Signal Input Connect 15 pin D-sub(Fem ale) or Option(6Pin, 5Pin)

Safety & EMC

Safety
EMC

cUL,CE,DHHS

FCC,CE
Power Voltage AC 90-264V, 60 / 50±3Hz
Power Consumption Nomal Operation

Input Current

at 120V

Input Current

at 240V

≤

120 Watts
Operating :≤1.5Amps rms.
Turn on :≤30Amps Peak.

Operating :≤0.8Amps rms.
Turn on :≤60Amps Peak.

Linearity Cross Pattern

Horizontal : 5%
Vertical : 5%

Environment

Temperature

Humidity

Operating : 0 to +40

℃

Storage : -40 to +60

℃

Operating : 10 to 85%
Storage : 5 to 95%

2. Product Specifications

KT-2914F KT-2914DF KT-2114DF KT-2114F

Tu be

29"Normal flat 29"Dyna flat 21"Dyna flat 21"Normal flat

Tu be Size(Diagonal)

730mm(29") 730mm(29") 550mm(21") 550mm(21")

Viewable Size(Diagonal) 605mm(27") 605mm(27") 508mm(20") 508mm(20")

Dot Pitch 0.79

㎜

(H) 0.79㎜(H) 0.74㎜(H) 0.74㎜(H)

Deflection Angle

90

°

90

°

90

°

90

°

Fo cusing Method Single Double Single Single

Norm al (H*V)

550*400 550*400 400*300 400*300

Maximum (H*V)

580*410 580*410 415*310 415*310

- 7 -

2-2 D-SUB SIGNAL CABLE SPECIFICATION

* VGA/SVGA SIGNAL CABLE PIN CONNECTION (15 PIN D-SUB MINIATURE SIGNAL

CONNECTOR WITH CABLE ; PCB CKT NO.: CN404 )

CONNECTION

REMARK

D-SUB 15PIN IBM PC WIRE COLOR 6P CONN 6P CONN

1 RED RED COAX-IN 6P CONN-6
2 GREEN GREEN COAX-IN 6P CONN-5
3 BLUE BLUE COAX-IN 6P CONN-4
4 N.C - ­5 GND BLACK 6P CONN-3
6 RED-GND -

RING WIRE7 GREEN-GND ­8 BLUE-GND ­9 N.C - -

10 ID - ­11 N.C - ­12 SDA - ­13 H-SYNC (C/S) ORANGE 6P CONN-1
14 V-SYNC WHITE 6P CONN-2
15 SCL - -

SHELL GND - RING WIRE

*

CGA / EGA 6PIN CONNECTION ( PCB CKT NO . : CN406 )

CONNECTION

REMARK

CGA SLOT ZAMMA Spec_ WIRE COLOR 6P CONN (@ PCB)

1 , A H-SYNC WHITE 6P CONN-6

16 V-SYNC YELLOW 6P CONN-5

28 , f GND & SHELL BLACK 6P CONN-4

T BLUE BLUE 6P CONN-3

17 GREEN GREEN 6P CONN-2

U RED RED 6P CONN-1

*

CGA / EGA 5PIN CONNECTION ( PCB CKT NO . : CN409 )

CONNECTION

REMARK

CGA SLOT ZAMMA Spec_ WIRE COLOR 5P CONN (@ PCB)

1 , A H/V COPOSITE-SYNC WHITE 5P CONN-5

28 , f GND & SHELL BLACK 5P CONN-4

T BLUE BLUE 5P CONN-3

17 GREEN GREEN 5P CONN-2

U RED RED 5P CONN-1

- 8 -

2-3 TIMING CHART

VIDEO

SYNC

HORIZONTAL VERTICAL

A

B

C D

E

O

P

Q R

S

A : LINE TIME TOTAL B :HORIZONTAL SYNC WIDTH
C : BACK PORCH D : ACTIVE TIME
E : FRONT PORCH

O : F RAME TIME TOTAL P : VERTICAL SYNC WIDTH
Q : BACK PORCH R : ACTIVE TIME
S : FRONT PORCH

DESCRPTION

CGA EGA VGA SVGA

640 x 200 640 x 200 640 x 400 640*480 800*600

H

f KHz 15.750 15.750 24.827 31.469 37.88
A uS 63.5 63.5 40.28 31.778 26.40
B uS 8.671 8.672 3.04 3.813 3.20

C uS 7.272 7.272 3.8 1.907 2.20
D uS 40.836 40.836 30.399 25.422 20.00

E uS 6.72 6.72 3.04 0.636 1.00

POL. POS POS POS NEG POS

V

f Hz 50 60.115 55.609 59.940 60.317

O mS 20.0 16.63 17.98 16.683 16.58

P mS 0.444 0.444 0.322 0.064 0.11

Q mS 0.825 0.825 1.26 1.048 0.61

R m S 18.603 15.302 16.111 15.253 15.84
S mS 0.128 0.06 0.282 0.318 0.03

POL. POS POS POS NEG POS

- 9 -

3-1 SET ASS'Y

3.2 MAIN PCB ASS'Y

3. Operating Instruction

- 10 -

3-3. Function of Control

Control Function

LED

(Power Indicator)

The light of power LED changes according to each state.

◎

on mode : Green LED.

◎

power saving mode : green LED blinking.

MENU(Sellect)

When you press this button, the MENU appears.The MENU will

disappear in 10 seconds if you don't operate any button.

When you press EXIT button again, the MENU disappears.
This button is used to select the control item on the MENU.
In M ENU, the control item could be selected and unselected by
this button.

EXIT This button is used to exit the value of any selected control.

UP

This button is used to increase the value of any selected control.
This button is used to locate to the next control item for select.

DOWN

This button is used to decrease the value of any selected control.
This button is used to locate to the previous control item for
select.

UP
DOWN
MENU (SELECT)
EXIT (DEGAUSSING)
LED

- 11 -

4-1. Adjustment Control

4-1-1. Before making Adjustments

1) Orientation
When servicing, always face the m onitor to east.

2) Warm-up tim e
The monitor m ust be on for 30 minutes before starting alignment. Warm-up
time is especially critical in color temperature and white balance

adjustments.

3) Signal
Analog, 0.714Vp-p positive at 75Ω, internal termination.

4) High Voltage Adjustment
Signal : without signal
Adjustment : 26KV±0.3KV.

PROCEDURE

①

Disconnect the AC line cord from the power source.

②

Connect positive end of High Voltage probe to anode cap of CRT, negative
end of to GND(main chassis)

③

First of all Disconnect AC cord and than disconnect High voltage probe.

5) Screen Voltage

- signal : 640 * 480 (60Hz) , Full white

- Bright : max

- Contrast : max

- Adjustment (SAM SUNG SDI) : 550±10V

4-1-2 TURN ON THE FACTORY OSD MANUAL METHOD

1) press on the "UP" key.

2) connect the AC line cord from the power source.

3) At this time OSD menu changed factory mode.

4.Adjustments

◑

HV AC VF

BRIGHTNESS

31.4KHz
60Hz

OSD

OSD

i

- 12 -

4-2. Display Control Adjustment

Click on the "MENU" button (OSD MENU).
This m enu is user's OSD manual.(user's manual)

1) Click on the "MENU" button.

2) Click on the "UP"or "DOWN" and move any function control.

3) Press the "MENU(SELECT)" button.

4) "UP" or "DOWN" button is used to control the value of any function.

5) When you press exit button, the MENU disappears.

4-2-1 Screen center adjustment

width : 520mm height : 400mm
signal : 640 * 480 (60Hz)
｜A-B｜≤ 4.0mm , ｜C-D｜≤ 4.0mm

a) Horizontal size adjustment

adjustment : use to "H-SIZE", 520±3mm

◑

BRIGHTNESS

31.4KHz 60Hz

DISPLAY AREA

SQUARE CORNER

A

D

C

B