LG RZ-23LZ41液晶彩电维修手册

RLCDTVSERVICEMANUALCAUTIONBEFORESERVICINGTHECHASSIS,READTHESAFETYPRECAUTIONSINTHISMANUAL.CHASSIS:ML-041AMODEL:RZ-23LZ41website:://(orFusibleResistor)inthisTVreceiverisblown,replaceitwiththespecified.Whenreplacingahighwattageresistor(OxideMetalFilmResistor,over1W),keeptheresistor10mmawayfromPCB.Keepwiresawayfromhighvoltageorhightemperatureparts.X-RAYRadiationWarning:Todeterminethepresenceofhighvoltage,useanaccuratehighimpedanceHVmeter.Adjustbrightness,color,contrastcontrolstominimum.Measurethehighvoltage.Themeterreadingshouldindicate23.5¡1.5KV:14-19inch,26¡1.5KV:19-21inch,29.0¡1.5KV:25-29inch,30.0¡1.5KV:32inchIfthemeterindicationisoutoftolerance,immediateserviceandcorrectionisrequiredtopreventthepossibilityofprematurecomponentfailure.Beforereturningthereceivertothecustomer,alwaysperformanACleakagecurrentcheckontheexposedmetallicpartsofthecabinet,suchasantennas,terminals,etc.,tobesurethesetissafetooperatewithoutdamageofelectricalshock.LeakageCurrentColdCheck(AntennaColdCheck)WiththeinstrumentACplugremovedfromACsource,connectanelectricaljumperacrossthetwoACplugprongs.PlacetheACswitchintheonposition,connectoneleadofohm-metertotheACplugprongstiedtogetherandtouchotherohm-meterleadinturntoeachexposedmetallicpartssuchasantennaterminals,phonejacks,etc.Iftheexposedmetallicparthasareturnpathtothechassis,themeasuredresistanceshouldbebetween1MΩand5.2MΩ.Whentheexposedmetalhasnoreturnpathtothechassisthereadingmustbeinfinite.Anotherabnormalityexiststhatmustbecorrectedbeforethereceiverisreturnedtothecustomer.LeakageCurrentHotCheck(SeebelowFigure)PlugtheACcorddirectlyintotheACoutlet.DonotusealineIsolationTransformerduringthischeck.Connect1.5K/10wattresistorinparallelwitha0.15uFcapacitorbetweenaknowngoodearthground(WaterPipe,Conduit,etc.)andtheexposedmetallicparts.MeasuretheACvoltageacrosstheresistorusingACvoltmeterwith1000ohms/voltormoresensitivity.ReverseplugtheACcordintotheACoutletandrepeatACvoltagemeasurementsforeachexposedmetallicpart.Anyvoltagemeasuredmustnotexceed0.75voltRMSwhichiscorrespondsto0.5mA.Incaseanymeasurementisoutofthelimitsspecified,thereispossibilityofshockhazardandthesetmustbecheckedandrepairedbeforeitisreturnedtothecustomer.LeakageCurrentHotCheckcircuitThesourceofX-RAYRADIATIONinthisTVreceiveristheHighVoltageSectionandtheLCDPANEL.ForcontinuedX-RAYRADIATIONprotection,thereplacementpanelmustbethesametypepanelasspecifiedintheReplacementPartsList.1.5Kohm/10WToInstrument'sexposedMETALLICPARTSGoodEarthGroundsuchasWATERPIPE,CONDUITetc.ACVolt-meterIMPORTANTSAFETYNOTICE0.15uF-4-CAUTION:Beforeservicingreceiverscoveredbythisservicemanualanditssupplementsandaddenda,readandfollowtheSAFETYPRECAUTIONSonpage3ofthispublication.NOTE:Ifunforeseencircumstancescreateconflictbetweenthefollowingservicingprecautionsandanyofthesafetyprecautionsonpage3ofthispublication,alwaysfollowthesafetyprecautions.Remember:SafetyFirst.GeneralServicingPrecautions1.AlwaysunplugthereceiverACpowercordfromtheACpowersourcebefore;a.Removingorreinstallinganycomponent,circu