Kortek KT-2914F User manual

SERVICEMANUAL
COLOR CRTMONITOR
KT-2914F/KT-2914DF
KT-2114F/KT-2114DF
KORTEK CORPORATION
DOC.NOKT-XX14X-SM
DATE2004 .02.02
REV.NO0
REV.DATE-

- 2 -
1.PRECAUTIONS-------------------------------------------------- 3
2.PRODUCTSPECIFICATION-------------------------------- 6
3.OPERATINGINSTRUCTION-------------------------------- 9
4.ADJUSTMENTS------------------------------------------------ 11
5.TROUBLE SHOOTING GUIDE---------------------------- 19
6.PART LIST------------------------------------------------------- 29
7.BLOCK DIAGRAM-------------------------------------------- 34
8.CONNECTINGDIAGRAM----------------------------------- 35
9.SCHEMATIC----------------------------------------------------- 36
10.PRINTCIRCUITBOARD ---------------------------------- 37
CONTENTS

- 3 -
1-1.Safetyprecautions
Warnings:Service should notbe attempted by anyoneunfamiliarwiththe
necessaryon thisMonitor.
The followingsarethe necessaryprecautionsto be observed beforeservicing.
1)Forcontinued safety,do notattempt tomodifythe circuitboard.
2)Disconnect the ACpowerbeforeservicing.
3)When the chassisisoperating,semiconductorheatsinks are potential
shock hazards.
1-1-1Servicing the high voltage volume areCRTWarnings
AHigh Voltage volumereplaced inthe wrong direction may cause excessive
X-Rayemissions.
1)Adjustin orderto 26KV withsignalatAnode.
2)When the troubleshootingamonitorwith excessivelyHigh Voltage,avoid
being unnecessarily closetothe monitor.Do notoperatethe monitorfor
longerthan isnecessarytolocatethe cause ofexcessivevoltage.
3)ExcessiveHigh Voltage can produce potentiallyhazardousX-RayRADIA-
TION.To avoidsuch hazards, the high voltage mustbe abovethe
specified limit. The nominalvalue of the High voltage of thisMonitoris
26KV ±0.3KV atzero beamcurrent(minimumbrightness)undera 120V
ACpowersource.The High Voltage mustnot(underany circumstances)
exceed 29KV.Eachtimeamonitor requires servicing, the High Voltage
shouldbechecked following the High Voltage check procedureonthis
manual. It isrecommended the reading of the voltage be recorded asa
partof the servicerecord.Itisimportant to use an accurate and reliable
High Voltage meter.
4)When the High Voltage regulatorisoperating properly, thereisno possib-
ilityofan X-Rayproblem.
5)The CRTisespeciallydesigned to prohibitX-rayemission.To ensure
continued X-rayprotection,replacethe CRTonlywith one thatisthe
same orequivalent type asthe original.
6)Handlethe CRTonlywhen wearing shatterproofgogglesand aftercompletely.
7)Do notlift the CRTbythe neck.
1.Precautions

- 4 -
1-1-2.Fire and Shock Hazard
Beforereturning the monitortothe user,performthe following safety checks:
1)Inspecteachlead dress tomakecertainthat the leadsare notpinched or
thathardwareisnotlodged between the chassisand othermetalparts
inthe monitor.
2)Inspectall protective devices such asnonmetallic controlknobs,insulating
materials,cabinetbacks,adjustmentand compartmentcoverorshields
isolation resistor-capacitornetworks,mechanical insulations,etc.
3)To be surethatno shock hazard exists,check forleakage currentinthe
following manner.
a.Plug the ACline cord directlyinto a 120 or230 VoltACoutlet.
(Do notuseanisolation transformerforthistest)
b.Using twoclipleads,connecta 1.5KΩ ,10Watt resistorparalleled bya
0.15Ufcapacitorinserialwith an exposed metalchassispartand a
known earth ground,such asan electricalconductorand electrical
ground connected to a earth ground.
c.UseaSSVMorVOMwith 1000 ohmsper-voltorsensitivitytomeasure
the ACvoltage drop across the resistor.
d.Connect the resistorto an exposed metalparthavingareturn pathto
the chassis(metalcabinet, screwheads,knobs,shafts,escutcheon,etc)
and measurethe ACvoltage drop across the resistor.
e.Anyreading of5.25 voltRMS(this correspondsto 3.5milliampereAC)
ormoreisexcessive and indicatesa potentialshock hazard.Correct
the shock hazard beforereturning the monitortothe user.
Figure 1-1.Leakage CurrentTestCircuit
LEAKAGE
CURRENT
TESTER
(READINGSHOULD)
NOTBE ABOVE
0.5mA
TESTALL
EXPOSEDMETAL
SURFACES
DEVICE
UNDER
TEST
2-WIRE
CORD
ALSOTESTWITH
PLUGREVERSED
(USINGACADAPTER
PLUGAS REQUIRED)Earth
ground

- 5 -
1-1-3.Productsafetynotices:
Some electricaland mechanicalpartshavespecialsafetyrelated characteristics
which are often notevident fromvisual inspection.The protection theygive
maynotbe obtained byreplacing themwithcomponentsrated forhighervolt-
age,wattage,etc.Partsthathavespecialsafety characteristics areidentified by
△on schematics and partslists.
Asubstitutereplacement thatdoesnothavethe samesafety characteristics
asthe recommended replacementpartmightcreateshock, fire and orother
hazards.Productsafetyisunder reviewcontinuouslyand newinstructions
wheneverappropriate.
1-2.Servicing Precautions
WARNING1:Firstreadthe"SafetyPrecaution"section of thismanual. if
unforeseencircumstances create conflictbetweenthe servicing
precautions and safetyprecautions,always followthe safety
precautions.
WARNING2:A High Voltage volumereplacedinthewrong direction may
cause excessive X-ray emissions.
WARNING3:Anelectrolytic capacitorinstalledwiththewrong polaritymight
explode.
1)Servicing precautionsare printed on the chassis,and shouldbefollowed
closely
2)Always unplug the unitsACpowercordfromthe ACpowersource before
attempting to:(a) remove or reinstall any componentorassembly,(b)
disconnectPCBplugsorconnectors,(c)connectall testcomponentsin
parallelwith an electrolytic capacitor.
3)afterservicing,always check that the screws,componentsand wiring have
been correctlyreinstalled.Makesurethat the area around the serviced
parthasnotbeen damaged.
4)Check the insulation between the bladesof the ACplug and accessible
conductive parts(examples:metalpanels,input terminalsand earphone jacks).
5)Neverdefeatanyof the +Bvoltage interlocks.Do notapplyACpowerto
the unit(oranyofitsassemblies)unless all solid-state heatsinks are
correctlyinstalled.
6)Always connectatestinstrumentsground lead tothe instrumentchassis
ground beforeconnecting the lead;always removethe instrumentslead last.

- 6 -
2-1SPECIFICATION
CDT
DisplayArea (mm)
BandwidthMaximum50MHz
Scanning Frequency
(AutoScanning)Horizontal Vertical15-40KHz 50-120Hz
MicroprocessorUserSaving Mode 6 Modes
UserControl
Display
Digital
Language
Position,Size,Pincushion,Trapezoid,H/Vcorner,
Pin-B,Trapezoid,Parallel,Tilt,Moire,Zoom
ColorTemperature,Recall,ManualDegauss
Eng/Ger/Fra/Esp/Port
Display colorColorTemperature 9300° K,6500° K,UserColor
Resolution Maximum Mode 800 X600 @60Hz
SignalInputConnect15 pinD-sub(Female)orOption(6Pin,5Pin)
Safety& EMCSafety
EMCcUL,CE,DHHS FCC,CE
PowerVoltage AC90-264V,60 /50± 3Hz
PowerConsumption NomalOperation
InputCurrent
at120V
InputCurrent
at240V
≤120 Watts
Operating :≤1.5Ampsrms.
Turn on :≤30AmpsPeak.
Operating :≤0.8Ampsrms.
Turn on :≤60AmpsPeak.
LinearityCross PatternHorizontal:5%
Vertical:5%
Environment
Temperature
Humidity
Operating :0to+40℃
Storage :-40 to+60℃
Operating :10 to 85%
Storage :5to 95%
2.ProductSpecifications
KT-2914FKT-2914DFKT-2114DFKT-2114F
Tube 29"Normalflat29"Dyna flat21"Dyna flat21"Normalflat
Tube Size(Diagonal)730mm(29")730mm(29")550mm(21")550mm(21")
ViewableSize(Diagonal)605mm(27")605mm(27")508mm(20")508mm(20")
DotPitch0.79㎜(H)0.79㎜(H)0.74㎜(H)0.74㎜(H)
Deflection Angle90°90°90°90°
Focusing Method SingleDoubleSingleSingle
Normal(H*V)550*400 550*400 400*300 400*300
Maximum(H*V)580*410 580*410 415*310 415*310

- 7 -
2-2D-SUB SIGNALCABLE SPECIFICATION
*VGA/SVGA SIGNALCABLE PIN CONNECTION(15 PIN D-SUBMINIATURE SIGNAL
CONNECTORWITH CABLE;PCBCKTNO.: CN404 )
CONNECTIONREMARK
D-SUB15PINIBMPCWIRECOLOR6PCONN 6PCONN
1RED RED COAX-IN6PCONN-6
2GREENGREEN COAX-IN6PCONN-5
3BLUE BLUECOAX-IN6PCONN-4
4N.C- -
5GND BLACK6PCONN-3
6RED-GND -RINGWIRE7GREEN-GND -
8BLUE-GND -
9N.C- -
10 ID- -
11 N.C- -
12 SDA- -
13 H-SYNC (C/S)ORANGE6PCONN-1
14 V-SYNC WHITE6PCONN-2
15 SCL- -
SHELL GND -RINGWIRE
*CGA/EGA6PIN CONNECTION(PCBCKTNO.:CN406 )
CONNECTIONREMARK
CGA SLOT ZAMMA Spec_WIRECOLOR6PCONN (@PCB)
1,AH-SYNC WHITE6PCONN-6
16 V-SYNC YELLOW6PCONN-5
28 , f GND & SHELL BLACK6PCONN-4
TBLUE BLUE6PCONN-3
17 GREENGREEN6PCONN-2
U RED RED6PCONN-1
*CGA/EGA5PIN CONNECTION(PCBCKTNO.:CN409 )
CONNECTIONREMARK
CGA SLOT ZAMMA Spec_WIRECOLOR5PCONN (@PCB)
1,AH/VCOPOSITE-SYNC WHITE5PCONN-5
28 , f GND & SHELL BLACK5PCONN-4
TBLUE BLUE5PCONN-3
17 GREENGREEN5PCONN-2
U RED RED5PCONN-1

- 8 -
2-3TIMINGCHART
VIDEO
SYNC
HORIZONTALVERTICAL
A
B
C D E
O
P
QRS
A:LINETIMETOTALB:HORIZONTALSYNC WIDTH
C:BACK PORCH D :ACTIVE TIME
E:FRONTPORCH
O:FRAMETIMETOTALP:VERTICALSYNC WIDTH
Q:BACK PORCH R :ACTIVE TIME
S:FRONTPORCH
DESCRPTIONCGA EGA VGA SVGA
640 x200 640 x200 640 x400 640*480 800*600
H
fKHz15.750 15.750 24.827 31.469 37.88
AuS63.5 63.5 40.28 31.778 26.40
BuS8.671 8.672 3.04 3.813 3.20
CuS7.272 7.272 3.8 1.907 2.20
DuS40.836 40.836 30.399 25.422 20.00
EuS6.72 6.72 3.04 0.636 1.00
POL.POS POS POSNEGPOS
V
fHz50 60.115 55.609 59.940 60.317
OmS20.0 16.63 17.98 16.683 16.58
PmS0.444 0.444 0.322 0.064 0.11
QmS0.825 0.825 1.26 1.048 0.61
RmS18.603 15.302 16.111 15.253 15.84
SmS0.128 0.06 0.282 0.318 0.03
POL.POS POS POSNEGPOS

- 9 -
3-1SETASS'Y
3.2MAINPCB ASS'Y
3.Operating Instruction

- 10 -
3-3.Function ofControl
ControlFunction
LED
(PowerIndicator)
The lightofpowerLEDchangesaccording to eachstate.
◎on mode :Green LED.
◎powersaving mode :green LEDblinking.
MENU(Sellect)
When you press thisbutton, the MENU appears.The MENU will
disappearin10secondsifyou don'toperate anybutton.
When you press EXITbutton again, the MENU disappears.
Thisbutton isused toselect the control itemon the MENU.
InMENU, the control itemcouldbeselected and unselected by
thisbutton.
EXIT Thisbutton isused to exit the value ofany selected control.
UPThisbutton isused toincreasethe value ofany selected control.
Thisbutton isused tolocatetothe nextcontrol itemforselect.
DOWNThisbutton isused to decreasethe value ofany selected control. Thisbutton isused tolocatetothe previous control itemfor
select.
UP
DOWN
MENU(SELECT)
EXIT(DEGAUSSING)
LED

- 11 -
4-1.AdjustmentControl
4-1-1.Beforemaking Adjustments
1)Orientation
When servicing,always facethe monitorto east.
2)Warm-up time
The monitormustbe on for30 minutesbeforestarting alignment. Warm-up
timeisespecially critical incolortemperature and white balance
adjustments.
3)Signal
Analog,0.714Vp-p positive at75Ω ,internaltermination.
4)High Voltage Adjustment
Signal:withoutsignal
Adjustment:26KV ±0.3KV.
PROCEDURE
①Disconnect the ACline cordfromthe powersource.
②Connectpositive end ofHigh Voltage probe to anode cap ofCRT,negative
end of toGND(mainchassis)
③Firstofall DisconnectACcord and than disconnectHigh voltage probe.
5)Screen Voltage
-signal:640 *480 (60Hz),Full white
-Bright : max
-Contrast : max
-Adjustment(SAMSUNGSDI):550± 10V
4-1-2TURN ONTHEFACTORYOSDMANUALMETHOD
1)press on the "UP"key.
2)connect the ACline cordfromthe powersource.
3)At thistimeOSDmenu changed factorymode.
4.Adjustments
◑
HV ACVF
BRIGHTNESS
31.4KHz
60Hz
OSDOSDi

- 12 -
4-2.DisplayControlAdjustment
Click on the "MENU"button (OSDMENU).
Thismenu isuser'sOSDmanual.(user'smanual)
1)Click on the "MENU"button.
2)Click on the "UP"or"DOWN"and move anyfunction control.
3)Press the "MENU(SELECT)"button.
4)"UP"or"DOWN"button isused tocontrolthe value ofanyfunction.
5)When you press exitbutton, the MENU disappears.
4-2-1Screen centeradjustment
width:520mm height : 400mm
signal:640 *480 (60Hz)
｜A-B｜≤ 4.0mm ,｜C-D｜≤ 4.0mm
a)Horizontalsize adjustment
adjustment : useto"H-SIZE",520±3mm
◑
BRIGHTNESS
31.4KHz60Hz
DISPLAY AREA
SQUARECORNER
A
D
C
B

- 13 -
b)Verticalsize adjustment
adjustment : useto"V-SIZE",400±3mm
c)Horizontalposition adjustment
adjustment : useto"H-POS"
d)Verticalposition adjustment
4-2-2Trapezoid adjustment
frequency :all mode
signalpattern:cross hatch
4-2-3Pin balance adjustment
frequency :all mode
signalpattern:cross hatch
4-2-4Parallelogramadjustment
frequency :all mode
signalpattern:cross hatch
A
B
A
B
｜A-B｜<2.5mm
D1D2D1
｜D1｜,｜D2｜≤1mm
5mm

- 14 -
4-2-5Side pin-cushion adjustment
frequency :all mode
signalpattern:cross hatch
brightness :MIN(cut-off)
contrast : MAX
｜C1｜,｜C2｜≤2.0mm,｜D1｜,｜D2｜≤2.0mm
4-2-6Tiltadjustment
frequency :all mode
signalpattern:cross hatch
brightness :MIN(cut-off)
contrast : MAX
4-2-7Degaussing adjustment
Don'tadjust the degaussing.Degaussing ispossibleinOSD
adjustmentmenu.Afterusing thisfunction once,You must
use again afteratleast30minutes.
4-2-8SAVE ADJUSTMENTCONDITION&REMOVE USERMODE.
D1
C1
C2
D2

- 15 -
4-3Coloradjustment
4-3-1colortemperature
※Setcondition
-measuring instrument:coloranalyzer (CA-100)
-frequency :640 *480 (60Hz)
-displaypattern: full white,one square(20%window)
-brightness :cutoff
-contrast : MAX
※specification
-9300Kx=0.281±0.02 ,y=0.311±0.02
-6500Kx=0.313±0.02 ,y=0.329±0.02
4-3-2coloradjustment(9300K)
a)Back rastercoloradjustment
※Setcondition
-frequency :640 *480 (60Hz)
-displaypattern:back rasterpattern
-brightness :MIN(cutoff)
-contrast : MAX
1.Select factorymode.
2.SelectCOLORTEMPwithUP.DOWNkey.
3.Select9300K.
4.Adjustback rasterbrightness to 0.01~0.02(F/L)withVR601.
5.SelectB-BwithUP,DOWNadjusty=0.311 and do the next
selection withEXITkey.
6.SelectR-BwithUP,DOWNadjustx=0.281 and do the next
selection withEXITkey.
a)white balance/ACL adjustment
※Setcondition
-frequency :640 *480 (60Hz)
-displaypattern:one square(20%window), full white
-brightness :MIN(cutoff)
-contrast : MAX

- 16 -
1.Select factorymode.
2.SelectCOLORTEMPwithUP,DOWNkey.
3.Select9300K.
4.SelectB-GwithUP,DOWNadjusty=0.311 and do the next
selection withEXITkey.
6.SelectR-GwithUP,DOWNadjustx=0.281 and do the next
selection withEXITkey.
7.Selectcontrasticon withUP,DOWNkey,adjustcontrast to
50~60f/lwithUP,DOWNkey.
8.SelectACLkey(A/C)infull white pattern and adjustACLto
28~30f/l.
※attention : If 50f/ldoesn'tadjustin 20%window,adjustG-G
againwithDOWNkey.
4-3-3coloradjustment(6500K)
a)white balance adjustment
1.Select factorymode.
2.SelectCOLORTEMPwithUP,DOWNkey.
3.Select6500K.
frontcabinet
back raster
20%windowpattern
frontcabinet
back raster
full white

- 17 -
4.SelectB-GwithUP,DOWNadjusty=0.329 and do the next
selection withEXITkey.
6.SelectR-GwithUP,DOWNadjustx=0.313 and do the next
selection withEXITkey.
4-3-4 brightness uniformityadjustment
※setcondition
-frequency :640 *480 (60Hz)
-displaypattern:9 ball pattern
-brightness :MIN(cutoff)
-contrast : MAX
Measure nine brightness displayinthe screen.
4-3-5Focusadjustment
※setcondition
-frequency :640 *480 (60Hz)
-displaypattern:"H"character
-brightness :min(cutoff)
-contrast : max
1.Adjustinfocusofwholescreen tobethe best fitted with
FOCUS V/RinFBT.
4-3-6PURITYadjustment
Purityisthatunnecessary colorsappearinthe screen except
displayed color.Don'tappearunnecessary colorsdivided with
the naked eye ata distance of50㎝fromCRTsurface.
frontcabinet

- 18 -
※setcondition
-direction :east
-frequency :included timing chart
-displaypattern: full white
-brightness :MIN(cutoff) - display center
Mostsuitable
REDx=0.640 ±0.015 y=0.323 ±0.015
GREENx=0.295 ±0.015 y=0.594 ±0.015
BLUEx=0.142 ±0.015 y=0.066 ±0.015

- 19 -
5-1.Troubleshooting Guide.
NOTES ;
1. If picture doesnotappear, fullyrotatethe brightness and contrastcontrols
clockwise.
2.Check the following circuits.
Norasterappear:powercircuit. Horizontaloutputcircuit.
High voltage controlcircuitand outputcircuit.
High voltage developsbutno rasterappears:Video outputcircuit.
High voltage doesnotdevelop :Horizontaloutputcircuit.
5.TROUBLESHOOTING GUIDE
NoPower
Check the othersecondary
outputs(+250V,+130V,+80V,+12V,
-12V,+12V,+6.3V,5VLines)
Doeseach outputappear?
Measure+80Voutputbetween
cathode ofD110 and Ground.
Doesappear80VDC?
Check and replace
F101,IC103
Check and replace
D104,D105,D106
D108,IC103,IC101
Check Video and
Horizontalcircuits
5-2-1.NoRaster,NoVideo
NO
YES
Check S1,S2,S3signalsreferto
S-correction tableonthe schematic
S1,S2,S3signalareright
ateachfrequency block Check and replace
Check and replace
Q704,707,709,703,706,708
YES
NO
5-2-2S-Correction failure.C/STABLE
S1S2S3
1~17KL L L
2 17~28KLLH
3 29~34KLH H
4 34~40KH H H
IC103 1pin

- 20 -
Degaussing
PurityisO.KDone
Degaussing circuit
isright?Referto 5-2-2
ReplaceCRTand
verifypurity
YES
YES
NO
NO
Check degauss
Connector(CN102)
Check outputvoltage atpin 12 of IC502
(Normal:0V,Degaussing:5V)
DoesDC voltage right?
Check and replace
Q101,D101,RL101,R101
ReplaceIC502
YES
YES
NO
5-2-3Degaussing failure
5-2-3Purityfailure