ViewSonic VS11755 User manual

ViewSonic VA1926W-9
Model No. VS11755
19 ColorTFT LCD Display
(Manufacturedate:NOV. 2008)
ServiceManual

1
Copyright
Copyright 2008 byViewSonicCorporation.Allrightsreserved.No partof thispublication maybe reproduced,
transmitted, transcribed,stored inaretrievalsystem,ortranslated intoanylanguage orcomputerlanguage,in any
formorbyanymeans,electronic,mechanical,magnetic,optical,chemical,manualorotherwise,withoutthe prior
written permission ofViewSonicCorporation.
Disclaimer
ViewSonicmakesno representationsorwarranties, eitherexpressed orimplied, withrespect tothe contentshereof
and specificallydisclaimsanywarrantyofmerchantabilityorfitness foranyparticularpurpose.Further,ViewSonic
reservesthe righttorevisethispublication and tomakechangesfromtimetotimeinthe contentshereofwithout
obligation of ViewSonictonotifyanyperson ofsuchrevision orchanges.
Trademarks
Optiquest isaregistered trademarkofViewSonicCorporation.
ViewSonicisaregistered trademark of ViewSonicCorporation.
Allothertrademarksused withinthisdocumentarethe propertyoftheirrespectiveowners.
Productdisposalatendofproductlife
The lampinthisproduct containsmercury. Pleasedisposeofinaccordancewithlocal, stateorfederal laws.
Revision History
Revision
SM Editing Date ECR Number DescriptionofChanges Editor
InitialRelease
T96MRADDIWVSNND
T96MRADDIWVSNNN
T96MRADKIWVSNND
T96MRADKIWVSNNN
A01 Dec9, 08
T96MRADTIWVSNND

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TABLEOFCONTENTS
1. PrecautionsandSafetyNotices..........................................................................................3
2. Specification.......................................................................................................................6
3. FrontPanel FunctionControl Description .......................................................................8
4. CircuitDescription.............................................................................................................15
5.AdjustingProcedure..........................................................................................................16
6.TroubleShooting Flow Chart............................................................................................23
7. Block Diagrams.................................................................................................................24
8. SchematicDiagrams........................................................................................................25
9. PCB LayoutDiagrams......................................................................................................33
10. ExplodedDiagramandSparePartsList.........................................................................40
11. RecommendedSparePartsList....................................................................................44
12. Differentpartslist........................................................................................................... 77

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1. PrecautionsandSafetyNotices
1.1AppropriateOperation
(1)Turnoffthe product beforecleaning.
(2)Useonlyadrysoftclothwhen cleaning theLCD panelsurface.
(3)Useasoft clothsoaked withmilddetergenttoclean the displayhousing.
(4)Useonlyahigh quality, safetyapprovedAC/DC powercord.
(5)Disconnect the powerplug fromthe ACoutletif the product willnotbe used foralong period of time.
(6)If smoke, abnormal noise, orstrange odorispresent, immediatelyswitchthe LCD displayoff.
(7)Do nottouchthe LCD panelsurfacewithsharporhardobjects.
(8)Do not placeheavyobjectson the LCD display,videocable,orpowercord.
(9)Do not useabrasivecleaners, waxesorsolventsforyourcleaning.
(10)Do not operatethe product underthefollowing conditions:
-Extremelyhot,coldorhumidenvironment.
-Areascontainingexcessivedust and dirt.
-Nearanyappliancegeneratingastrong magneticfield.
-Indirectsunlight.
1.2. Caution
No modification of anycircuitshouldbe attempted. Servicework shouldonly
beperformed afteryou arethoroughlyfamiliar
withallof the following safetychecksand servicing guidelines.
1.3. SafetyCheck
Careshouldbe taken whileservicing thisLCD display. Becauseofthe high voltage used inthe invertercircuit,the volta
ge is
exposed insuchareasasthe associated transformercircuits.
1.4. LCD ModuleHandling Precautions
Handling Precautions
(1)Sincefrontpolarizeriseasilydamaged, payattentionnot toscratchit.
(2)Besuretoturnoff powersupplywhen connecting ordisconnecting input connector.
(3)Wipe off waterdropsimmediately.Long contact withwatermaycausediscoloration orspots.
(4)When the panelsurfaceissoiled,wipe it withabsorbent cotton orothersoft cloth.
(5)Sincethe panelismade of glass, it maybreakorcrack if dropped orbumped on hardsurface.
(6)SinceCMOSLSIisused inthismodule, takecareof staticelectricityand ensurehuman earthwhen handling.
(7)Do not open ormodifytheModuleAssembly.
(8)Do not press the reflectorsheet atthe back of themoduleinanydirection.
(9)Inthe eventthat aModulemust be put back intothepacking containerslot afterit wastaken out ofthe
container,do not press the centerof the CCFLReflectoredge. Instead, press at the farendsofthe
CFLReflectoredge softly.Otherwisethe TFTModule maybe damaged.
(10)Atthe insertion orremoval ofthe Signal InterfaceConnector, be surenot torotateortiltthe Interface
Connectorof the TFTModule.
(11)Afterinstallation of the TFTModuleintoan enclosure(LCD monitorhousing,forexample), do not twist or
bend the TFTModuleevenmomentarily.When designing the enclosure,it shouldbe taken intoconsideration
that no bending/twisting forcesmaybe appliedtothe TFT Modulefromoutside.Otherwisethe TFT Module
maybe damaged.
(12)The coldcathode fluorescent lampinthe LCD containsasmallamount ofmercury. Pleasefollowlocal

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ordinancesorregulationsfordisposal.
(13)The LCD modulecontainsasmallamount ofmaterialshavingno flammabilitygrade.The LCD module
shouldbe supplied withpowerthat complieswiththe requirementsof Limited PowerSource
(IEC60950 orUL1950), oran exemption shouldbe applied for.
(14)The LCD moduleisdesigned sothat the CCFLinitissupplied byaLimited CurrentCircuit (IEC60950
orUL1950). Do notconnectthe CCFLtoaHazardousVoltage Circuit

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CorrectMethodsIncorrectMethods
Onlytouchthe metal-frameofthe panelorthe front
coverofthe monitor.
Do not touchthe surfaceofthe polarizer.
Surfaceof the panelispressed byfingersand that
maycause “MURA “
Takeout the monitorfromcarton. Takeout the monitorbygrasping theLCD panel.
Thatmaycause “MURA“.
Placethe monitoron aclean &soft foampad . Placethe monitoron foreign objectsand
that couldscratchthe surfaceof panel.

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2. Specification
2.1Productspecifications
Product Name VA1926w
OracleP/N VA1926W-9
ModelNumber VS11755
OSDLanguages
English,French,German,Italian, Spanish,
Finnish, Japanese, Russian Simplified Chinese,
TraditionalChinese, Korean
TFTLCD Panel and Model # 1st panel:CMOA190A2
Scalar RTD2533VH
Input Signal Analog x1/ Digitalx1
SyncCompatibility SeparateSync/CompositeSync/SOG
Adapter InternalPowerBoard
PowerCable Yes,
refertoAPPENDIXB:PowerCable
Analog Cable(1.8m,black), withPC2001 and HotPlug
Detect &DDC Yes (Detached cable; refertheAppendixA)
DVI-DCable(1.8m,black)withPC2001 ForRegion code =P/A/J/K/Sunitsonly
AudioCable(1.8m, black)withPC2001 No
MICCable(1.8m,black)withPC2001 No
USB Cable(V2.0) No
ViewSonicCD Wizard
Arabic,English,Finnish, Spanish, German,
Italian, Japanese, Swedish, Polish, Korean,
Portuguese, Russian,Turkish, French, Czech,
Hungarian, Simplified Chinese,Traditional
Chinese
Greek, Dutch,Bulgarian, Croatian,Romanian,
Serbian, Slovak, Slovenian
ViewSonicQuickStartGuide One Page
PerfectSuiteCD No
Screen ProtectorMylar Yes
Foot Protectorplastic No
BaseassemblyProcedureCard Yes
Energystart sticker Yes
VistaInstall CardYes
DCR Sticker Yes
ServiceInsert ForRegion code =Munitsonly
WarrantyCard ForRegion code =Gunitsonly
Carton Sticker ForRegion code =Gunitsonly
PE bag ofCarton ForRegion code =Gunitsonly
Manufactureaddress sticker ForRegion code =Gunitsonly

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2.2Interface description
1 5
610
11 15
VideoConnectorPinAssignment
A-1.15 pinD-subconnectorpinassignment
PinNumber PinFunction
1 Red video input
2 Green video input
3 Blue video input
4 No Connection
5 Ground
6 Red video ground
7 Green video ground
8 Blue video ground
9 +5V
10 H/Vsyncground
11 No connection
12 (SDA)
13 Horizontalsync(Compositesync)
14 Vertical sync
15 (SCL)
A-2. 24 pinDVI-Dconnectorpinassignment
PinNo. Signal Name Description
1 RX2- TMDSnegativedifferentialinput,channel2
2 RX2+ TMDSpositivedifferential input, channel 2
3 GND LogicGround
4 Reserved 4 Reserved.No connection
5 Reserved 5 Reserved.No connection
6 DDC-CLK DDC Clock
7 DDC-DAT DDC Data
8 Reserved 8 Reserved.No connection
9 RX1- TMDSnegativedifferentialinput,channel1
10 RX1+ TMDSpositivedifferential input, channel 1
11 GND LogicGround
12 Reserved 12 Reserved.No connection
13 Reserved 13 Reserved.No connection
14 VCCX Power
15 GND LogicGround
16 SENS SENSE Pin,PullHigh
17 RX0- TMDSnegativedifferentialinput,channel0
18 RX0+ TMDSpositivedifferential input, channel 0
19 GND LogicGround
20 Reserved 20 Reserved.No connection
21 Reserved 21 Reserved.No connection
22 GND LogicGround
23 RXC+ TMDSpositivedifferential input, referenceclock
24 RXC- TMDSnegativedifferentialinput,referenceclock

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3. FrontPanel FunctionControl Description
“MainMenu Controls
MainMenu
withOSDcontrols
FrontControlPanel
shownbelowindetail
Displaysthe control screen
forthehighlightedcontrol.
Alsotogglesbetweentwo
controlsonsomescreens.
Alsoashortcuttotoggle
analoganddigital
connection.
Displaysthe
MainMenu or
exitsthe
controlscreen
and saves
adjustments.
Powerlight
Blue =ON
Orange =PowerSaving
StandbyPower
On/Off
Scrollsthrough
menu optionsand
adjuststhe
displayed control.
Alsoashortcut to
displaythe
Contrast
adjustmentcontrol
screen.

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Do thefollowingtoadjustthedisplay setting:
1. Todisplaythe MainMenu,press button [1].
NOTE: AllOSDmenusand adjustment screensdisappearautomaticallyafterabout 15
seconds. Thisisadjustablethrough the OSDtimeoutsettinginthe setup menu.
2. Toselect acontroltoadjust, press ortoscrollup ordowninthe MainMenu.
3. Afterthe desired controlisselected, press button [2].Acontrol screen likethe one shown
belowappears.
The line atthe bottomofthe screen shows
the currentfunctionsof buttons1and 2:
Exit orselect the Brightness control.
4. Toadjust thecontrol, press the up ordownbuttons.
5. Tosavethe adjustmentsand exit themenu, press button [1] twice.
Thefollowing tipsmay help youoptimizeyourdisplay:
•Adjust the computer'sgraphicscardsothatit outputsa1440 x900 @60Hzvideo signalto
the LCD display.(Lookforinstructionson “changing therefreshrate”inthe graphicscard's
userguide.)
•If necessary, makesmalladjustmentsusing H. POSITIONand V.POSITIONuntilthe
screen image iscompletelyvisible. (The blackborderaround the edge of the screen should
barelytouchthe illuminated “activearea”of the LCD display.)

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Main Menu Controls
Adjust the menu itemsshownbelowbyusing the up and downbuttons.
Control Explanation
Auto ImageAdjust automaticallysizes, centers, and fine tunesthe video signal
Autoeliminatewaviness and distortion. Press the [2] button toobtainasharper
image.
NOTE: AutoImage Adjust workswithmost commonvideo cards. Ifthis
functiondoesnot work on yourLCD display,then lowerthe video refreshrate
to60 Hzand set theresolution toitspre-setvalue.
Contrast adjuststhe differencebetween the image background (black level)
and the foreground (whitelevel).
Brightness adjustsbackground black level of the screen image.
InputSelect togglesbetween inputsifyou havemorethan one computer
connected tothe LCD Display.
ColorAdjust providesseveral coloradjustmentmodes,including preset color
temperaturesand aUserColormode whichallowsindependent adjustment of
red (R), green (G),and blue (B).The factorysetting forthisproductis6500K
(6500 Kelvin).
sRGB-Thisisquicklybecoming the industry standardforcolormanagement,
withsupport being included inmanyof the latest applications. Enabling this
setting allowsthe LCD displaytomoreaccuratelydisplaycolorsthe waythey
wereoriginallyintended. Enabling the sRGBsetting will causethe Contrast and
Brightness adjustmentstobe disabled.
9300K-Addsblue tothe screen image forcoolerwhite(used inmost office
settingswithfluorescentlighting).

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Control Explanation
6500K-Addsred tothe screen imageforwarmerwhiteand richerred.
5400K-Addsgreen tothe screen image foradarkercolor.
User Color Individualadjustmentsforred (R), green (G), and blue (B).
1. Toselect color(R,G orB) press button [2].
2. Toadjust selected color,press and.
Important: If you selectRECALL fromtheMainMenu whenthe productisset
toaPresetTiming Mode, colorsreturntothe 6500Kfactory preset.
Information displaysthe timing mode (video signal input)coming fromthe
graphicscardinthe computer, theLCD model number,the serial number, and
the ViewSonic®websiteURL.See yourgraphicscard’suserguide for
instructionson changing the resolution and refreshrate(verticalfrequency).
NOTE: VESA1440 x900 @ 60Hz(recommended)meansthat the resolution is
1440 x900 and the refreshrateis60 Hertz.
ManualImageAdjust displaysthe ManualImage Adjust menu.
H./V.Position (Horizontal/VerticalPosition) movesthe screen image left or
right and up ordown.
H. Size(HorizontalSize) adjuststhe widthof the screen image.
FineTune sharpensthe focusbyaligning textand/orgraphicswithpixel
boundaries.
NOTE: Try AutoImage Adjustfirst.

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Control Explanation
Sharpness adjuststhe clarityand focusofthe screen image.
Aspectratio Selectsthe image sizefor4:3and fullscreen.
ECO Mode providesthe lowerpowerconsumption byreducing the brightness.
Standard: The default brightness setting
Optimize: Decreasesthe brightnessby25 %
Conserve: Decreasesthe brightnessby50 %
NOTE: When the ECO Mode isset to"Optimize"or"Conserve",the
Brightness, Contrast, and DynamicContrast cannot be adjusted.
SetupMenu displaysthe menu shownbelow:
Language Select allowsthe usertochoosethe language used inthe menusand
controlscreens.
Resolution Notice advisesthe optimalresolution touse.
OSDPosition allowsthe usertomovetheOSDmenusand control screens.
OSDTimeout setsthe lengthof timethe OSDscreen isdisplayed. Forexample,
witha “15 second”setting,if acontrolisnot pushed within15 seconds, the
displayscreen disappears.
OSDBackground allowsthe usertoturnthe OSDbackground OnorOff.
Memory Recall returnsthe adjustmentsback tofactory settingsif the displayis
operating inafactory Preset Timing Mode listed inthe Specificationsofthis
manual.
Exception: Thiscontrol doesnot affectchangesmade withthe UserColor
control,Language SelectorPowerLock setting.

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4. CircuitDescription
The RTD2533V(H)istotalsolution graphicsprocessing ICforLCD monitorswithpanelresolutionsup toWXGA.It
isconfigured withahigh-speed integrated triple-ADC/PLL, an integrated DVIreceiver, ahigh qualitydisplay
processing engine, and an integrated output displayinterfacethatcan support RSDSpanelinterfaceformat.To
furtherreducesystemcosts, the RTD2533V(H)alsointegratesintelligent powermanagement controlcapabilityand
spread-spectrumsupportforEMI management.The RTD2533V(H)incorporatesthe world’sfirstcoherent
oversampled RGBgraphicsADC inamonitorcontrollersystem.The oversampling ADC samplesthe input RGB
signalsat afrequency thatismuchhigherthan the signalsourcepixelrate.Thiscan preservedetailsinthe video
signalthatordinarilywouldbe lost due toinput signaljitterorbandwidthlimitationsinnon-oversampled systems.
The RTD2533V(H)alsoforthe digitaloutput video tothe displaypanelthat preservesthe advantagesofafixed
output clock rate, whileeliminating the output end offrameshort-line.
Analog RGBToPanel
Analog HSYN
C/
DVI
XTAL/EXTCLKinterface
Dual
interface
engine
Displayprocessing
engine
RSDSPanel
interface
OSD Clock Gen
MCU

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5.AdjustmentProcedure
1.All Modes Reset
Youshoulddo “All Model Reset (RefertoChap3. HotKeysforFunctionControls)
first.Thisactionwillallow youtoerase all end-user’ssettingsandrestorethe
factorydefaults.
2.AutoImageAdjust
TheAutoAdjustisaimedtoofferabestscreenqualitybybuilt-inASIC.Foroptimum
screenquality, theuserhas toadjusteachfunctionmanually.
A.Turnthecomputerand LCD monitoron.
B. Press the ‘Auto’button on monitorkeypad toAutoAdjust.
C.The LCD monitorwillstart the AutoAdjust process automaticallyand run for10
consecutiveseconds, during whichtimeyou willnoticethe image change.
3. Firmware
TestPatten:BurninModel (RefertoChap3. HotKeysforFunctionControl)
-Make suretheF/Wisthelatestversion.
4. DCC
Test Patten:EDIDprogram
-Make sureitcanpass testprogram.
5. Window ShutDown
TestSignal:1280*1024@60Hz
TestPattern:
CheckeredPatternEveryOnePixel (50%Green&50%Blue)
InspectionItem:Flicker, Mura
6. Window BG
TestSignal:1280*1024@60Hz
TestPattern:
Window standardpattern
InspectionItem:LineDefect,FunctionDefect&Mura

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7. 25 Gray
TestSignal:1280*1024@60Hz
TestPattern:
Full Screen25%White(Gray)
InspectionItem:Particle, LineDefect&Mura
8. 50 Gray
TestSignal:1280*1024@60Hz
TestPattern:
Full Screen50%White(Gray)
InspectionItem:BrightDot, Particle,LineDefect&Mura
9. WhiteBox
TestSignal:1280*1024@60Hz
TestPattern:
Window standardpattern
InspectionItem:Particle, LineDefect, Power, ImageRemain&Mura
10. Black Box
TestSignal:1280*1024@60Hz
TestPattern:
Window standardpattern
InspectionItem:BrightDot, LineDefect&Power
11. RED
TestSignal:1280*1024@60Hz
TestPattern:
Full ScreenRed
InspectionItem:BrightDot, Partial &LineDefect

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12. Green
TestSignal:1280*1024@60Hz
TestPattern:
Full ScreenGreen
InspectionItem:BrightDot, Partial &LineDefect
13. Blue
TestSignal:1280*1024@60Hz
TestPattern:
Full ScreenGreen
InspectionItem:BrightDot, Partial &LineDefect
14. Gray_Scale_0-100_V64
TestSignal:1280*1024@60Hz
TestPattern:
Vertical 64 (256)GrayScale(Right Left，From0to100%White)
InspectionItem:LineDefect&FunctionDefect
15. FunctionTestDisplaypattern
Item
Pattern Description Remark
1 Gray_Scale_0-100_V Vertical64(256) GrayScale( →左，From0to
100% White) Figure1
2 Gray_Scale_0-100_H Horizontal64 (256)GrayScale(上→下，From0
to100% White) Figure2
3 Black Full ScreenBlack Figure3
4 Red Full Screen50%Red Figure4
5 Green Full Screen50%Green Figure5
6 Blue Full Screen50%Blue Figure6
7 White Full ScreenWhite Figure7
8 Black_Tile BlackTileUnderWhiteBackground Figure8

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Figure1 Figure2
Figure5
Figure4
Figure6
Figure3
Figure5

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RTD2120 ISPuserflow
Software:RTDISPVer3.0
Hardware : PrinttoD-Suband DVI-DConverter
Step1.UpdateBIOSFlow：
ExecuteISP.exe
Figure8Figure7

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Step2.
Click【64K】, Selectthefirstfilenamexxxxxxxxxx_1.hexand
Click【64~96】, Selectthesecondfilenamexxxxxxxx_2.hex
Step3.
Select【Both】and 【Auto】.