Specifications

Chapter 2: 7401-4xxx Product Overview 2-23
LCD Backlight Inverter Module
AnInverterBoardsuppliespowerfortheLCDBacklight,whichisa
separatemoduleintheterminal.Theinverterhasaconnectorthat
receivespower,ground,andaBacklightdimmingsignalfromthe
ProcessorBoard.Theinvertergeneratesthehighvoltagenecessaryto
startandrundualCCFL(cold‐cathodefluorescent
lamps)Backlights.
AfuselocatedontheInverterBoardprotectspowertotheinverter.
ThisfuseprotectsthesystemfromdamageintheeventofaBacklight
orInverterBoardfault.Thefuseisnotfieldreplaceable;ifitblows,the
safetycharacteristicsofoneormorecomponentsonthe
InverterBoard
mayhavebeencompromisedandtheInverterBoardshouldbe
replaced.
IfoneorbothBacklighttubesbecomedisconnectedorotherwiseopen‐
circuited,protectioncircuitryshutsdowntheinverter.Thisavoids
over‐poweringasingletubeandalsoprotectsagainsthighvoltage
shorting.
TheBacklighttubesfortheActive
displays(TFT)canbereplaced.
Touch Screen
TheTouchScreencompletelycoverstheLCDandismounteddirectly
infrontoftheLCD,behindthefrontplasticbezeloftheterminal.The
touchcontrollerontheProcessorBoardsupportscapacitiveand
resistivetouchglass.
Thetouchglasshasanintegratedharnessthatisroutedintothe
ProcessorBoard
enclosureandisconnectedtoaheaderonthe
ProcessorBoard.
Thetouchglasshasaglare‐reducingtexturethatalsohelpshide
fingerprints.