Panasonic PT43LCX64 - MMD DIGITAL TUNER User manual

1.1GENERALGUIDELINES
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1.Forcontinuedsafety,no modification ofany circuit shouldbeattempted.
2.DisconnectACPlug beforedisassembling thisunit.
3.Itisadvisabletouseanisolation transformerintheACsupplybeforeservicing.
4.Whenservicing,observetheoriginalleaddress.Ifashortcircuit isfound,replace all parts
whichhavebeenoverheatedordamagedby theshortcircuit.
5.Afterservicing,seetoitthatalltheprotectivedevicessuchasinsulation barriers,insulation
papers,shield,and isolation R-Ccombinationsetc.areproperlyinstalled.
6.Afterservicing,besuretorestorethewires,leads,insulation barriers,shields,etc.
7.Afterservicing,maketheleakagecurrentcheckstopreventthecustomerfrombeing exposed
toshockhazards.
Caution:
UseaseparateIsolation Transformerforthisunit whenservicing.
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1.1GENERALGUIDELINES
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1.Forcontinuedsafety,no modification ofany circuit shouldbeattempted.
2.DisconnectACPlug beforedisassembling thisunit.
3.Itisadvisabletouseanisolation transformerintheACsupplybeforeservicing.
4.Whenservicing,observetheoriginalleaddress.Ifashortcircuit isfound,replace all parts
whichhavebeenoverheatedordamagedby theshortcircuit.
5.Afterservicing,seetoitthatalltheprotectivedevicessuchasinsulation barriers,insulation
papers,shield,and isolation R-Ccombinationsetc.areproperlyinstalled.
6.Afterservicing,besuretorestorethewires,leads,insulation barriers,shields,etc.
7.Afterservicing,maketheleakagecurrentcheckstopreventthecustomerfrombeing exposed
toshockhazards.
Caution:
UseaseparateIsolation Transformerforthisunit whenservicing.
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1.2LEAKAGE CURRENTCOLDCHECK
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1.Unplug theACcordand connectajumperbetweenthetwoprongson theplug.
2.Forphysicallyoperatedpowerswitches,turnpoweron.Otherwiseskipstep2.
3.Measuretheresistance value,withanohmmeter,betweenthejumperedACplug and each
exposedmetalliccabinetparton thereceiver,suchasscrewheads,connectors,etc.Whenthe
exposedmetallicparthasareturnpathtothechassis,thereadingshouldbebetween1M and
12 M .Whentheexposedmetaldoesnothaveareturnpathtothechassis, thereading must
beinfinity.
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1.3LEAKAGE CURRENTHOTCHECK
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1.Plug theACcorddirectlyintotheACoutlet.
Donotuseaisolation transformerforthischeck.
2.Connecta1.5k ,10 Wresistor,inparallelwitha0.15 μFcapacitor,betweeneachexposed
metallicparton thesetand agood earthground,asshowninFigure1.
3.UseanACvoltmeter,with1k /Vormoresensitivity,tomeasurethepotentialacrossthe
resistor.
4.Checkeachexposedmetallicpart,and measurethevoltageateachpoint.
5.ReversetheACplug intheACoutletand repeateachoftheabovemeasurements.
6.Thepotentialatany pointshouldnotexceed0.75 VRMS.
Aleakagecurrenttester(Simpson Model229 equivalent)maybeusedtomakethehotchecks.
Leakagecurrentmustnotexceed1/2mA.Incaseameasurementisoutsideofthelimits
specified,thereisapossibilityofshockhazard,and thereceivershouldberepairedand
recheckedbeforeit isreturnedtothecustomer.
Figure1
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1.4UV-PRECAUTION
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1.BesuretodisconnecttheACPlugwhenreplacing thelamp.
2.Sincethelampreachesaveryhigh temperatureduring itsoperation,wait untilit has
completelycooledoffwhenreplacing theLampUnit.
3.ThelampemitssmallamountsofUV-Radiation.
Avoiddirect-eyecontactby covering theLampand wearing theUV cutprotectiveglass.
4.Thehigh pressurelampinvolvesariskofexplosion.
Figure2
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2PREVENTIONOFELECTROSTATIC
DISCHARGE(ESD)TO
ELECTROSTATICALLYSENSITIVE(ES)
DEVICES
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Somesemiconductor(solidstate)devicescanbedamagedeasilyby staticelectricity.Such
componentscommonlyarecalledElectrostaticallySensitive(ES)Devices.ExamplesoftypicalES
devicesareintegratedcircuitsand somefield-effecttransistorsandsemiconductor"chip"components.
Thefollowing techniquesshouldbeusedtohelpreduce theincidence ofcomponentdamagecaused
by electrostaticdischarge(ESD).
1.Immediatelybeforehandling any semiconductorcomponentorsemiconductor-equipped
assembly,drainoffany ESDon yourbody by touching aknownearthground.Alternatively,
obtainand wearacommerciallyavailabledischarging ESDwriststrap,whichshouldbe
removedforpotentialshockreasonspriortoapplying powertotheunit undertest.
2.Afterremoving anelectricalassemblyequippedwithESdevices,place theassemblyon a
conductivesurfacesuchasaluminumfoil,topreventelectrostaticchargebuildup orexposure
oftheassembly.
3.Useonlyagrounded-tipsoldering iron tosolderorunsolderESdevices.
4.Useonlyanantistaticsolderremovaldevice.Somesolderremovaldevicesnotclassifiedas
"antistatic(ESDprotected)"cangenerateelectricalchargesufficienttodamageESdevices.
5.Donotusefreon-propelledchemicals.Thesecangenerateelectricalchargessufficientto
damageESdevices.
6.DonotremoveareplacementESdevice fromitsprotectivepackageuntilimmediatelybefore
you areready toinstall it.(MostreplacementESdevicesarepackagedwithleadselectrically
shortedtogetherby conductivefoam,aluminumfoil orcomparableconductivematerial).
7.Immediatelybeforeremoving theprotectivematerialfromtheleadsofareplacementES
device,touchtheprotectivematerialtothechassisorcircuit assemblyintowhichthedevice
willbeinstalled.
CAUTION :
Besureno powerisappliedtothechassisorcircuit,and observeall othersafetyprecautions.
8.Minimize bodilymotions whenhandling unpackagedreplacementESdevices.(Otherwise
harmlessmotion suchasthebrushing togetherofyourclothesfabricorthelifting ofyourfoot
fromacarpetedfloorcangeneratestaticelectricity(ESD)sufficienttodamageanESdevice).
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3ABOUTLEADFREE SOLDER(PbF)
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4SERVICENOTES
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5DISASSEMBLY/ ASSEMBLY
PROCEDURES
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5.1CABINETSECTION
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