ViewSonic VS11755 User manual

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

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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.)