Panasonic TX-22LT2F User manual

22”Diagonal LCD TV 1
Specifications1
1. SafetyPrecautions3
1.1. General Guidelines 3
1.2. Touch-CurrentCheck 3
2. Prevention ofElectro StaticDischarge(ESD) toElectrostaticallySensitive (ES)Devices 4
3. Aboutleadfree solder(PbF)5
4. SelfCheck 7
5. ChasisBoard Layout8
6. Servicing method 8
6.1. Removing tiltbase 9
6.2. Removing rearpanel 9
6.3. Removing speakerunit9
6.4. Removing chassis10
6.5. Removing A-Board 11
6.6. Removing B-Board (withtunerassembly)13
6.7. Removing DG-Board 13
6.8. Removing H1-Board and H2-Board 14
6.9. Removing P1-Board 14
6.10. Removing P2-Board 14
6.11. Removing K-Board 15
6.12. Removing V-Board 15
6.13. A-Board servicing 15
7. Service ModeFunction 16
7.1. HowtoenterSERVICE 116
7.2. HowtoenterSERVICE 216
7.3. Option Description 17
8. Conductor Views19
8.1. A-Board 19
8.2. B, H1, H2, K, P1and P2-Board 19
8.3. DG-Board 19
9. Block and SchematicDiagrams19
9.1. SchematicDiagram Notes 19
9.2. PowerBlock Diagram 20
9.3. Signal Block Diagram 20
9.4. Interconnection SchematicDiagram 20
9.5. A-Board (1of7)and H1-Board SchematicDiagram 20
9.6. A-Board (2of7)and H2-Board SchematicDiagram 20
9.7. A-Board (3of7)SchematicDiagram 20
9.8. A-Board (4of7), B-Board, K-Board and V-Board SchematicDiagram 20
9.9. A-Board (5of7), P1-Board and P2-Board SchematicDiagram 20
9.10. A-Board (6of7)and P1-Board SchematicDiagram 20
9.11. A-Board (7of7)SchematicDiagram 20
9.12. DG-Board (1of7)SchematicDiagram 20
9.13. DG-Board (2of7)SchematicDiagram 20
9.14. DG-Board (3of7)SchematicDiagram 20
9.15. DG-Board (4of7)SchematicDiagram 21
9.16. DG-Board (5of7)SchematicDiagram 21
9.17. DG-Board (6of7)SchematicDiagram 21
9.18. DG-Board (7of7)SchematicDiagram 21
svcdoc
I
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

10. PartsLocation &Mechanical ReplacementPartsList21
10.1. PartsLocation 21
10.2. Packing ExplodedView21
10.3. Mechanical ReplacementPartsList22
11. ReplacementPartsList24
11.1. ReplacementPartsListNotes 24
11.2. Electrical ReplacementPartsList25
12. SchematicDiagram for printing withA4size46
svcdoc
II
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

ORDERNO. ITD0203006C2
22”Diagonal LCD TV
TX-22LT2F
LH4Chassis
SPECIFICATIONS
Specifications
PowerSource
AC100~240V, 50/60Hz
PowerConsumption
Averageuse:67W
Stand-bycondition:5W
TVset: DC15V, 4.1Amax.
LCD
22-inch(558mm), 16:9aspectratio LCDpanel
Screen Size
19.17-inch (486.7mm)(W)x10.77-inch (273.6mm)(H)x/ 22-
inch (558mm)(Diagonal)
Sound
Speaker
Tweeter(4x7cm 2pcs, 8 ), Woofer( 5cm 2pcs, 4 )
Audio Output
9W (2.5W+2.5W+4.0W (Woofer)), 10%THD
Headphones
M3(3.5mm)Jack x18 impedance
FEATURES
Aero-Hammer DoubleWooferSystem (2Way
4SpeakerSystem)
Receiving Systems/ Band name
1
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

PAL B,G,H, SECAMB,GSECAML/L’
VHF E2-E12 VHF H1-H2(ITALY)
VHF A-H(ITALY) UHF E21-E69
CATV(S01-S05) CATVS1-S10 (M1-M10)
CATVS11-S20 / (U1-
U10)
CATVS21-S41 (Hyperband)
PAL 525/60
Playback ofNTSCtapefromsome PAL video recorders
(VCR)
M.NTSC
Playback fromM.NTSCVideo recorders(VCR)
NTSC
Playback fromNTSCVideo recorders(VCR)
(AVINPUTONLY)
Aerial-Rear
UHF-VHF
Operating Conditions
Temperature:41°F-95°F(5-35°C)
Humidity:5%-90%RH(non-condensing)
Connection Terminals
AV1
21Pin socket(Audio/Video in, TVout, RGBin)
AV2
21Pin socket(Audio/Video in, Audio/Video out, S-Video, Q
-Link)
AV3
VIDEO
RCAPINTypex1
S-VIDEO
Mini DIN4-pin
AUDIOL-R
RCAPINTypex2
Dimensions(W xHxD)
Including TVStand
586mm x424mm x240mm
TVSetOnly
586mm x388mm x67mm
Weight(Mass)
11.5kg Net
Note:
Design and Specificationsaresubjectto changewithoutnotice.
Weightand Dimensionsshown areapproximate.
2002 Matsushita ElectricIndustrial Co., Ltd. All rights reserved.
Unauthorizedcopying and distribution isaviolation oflaw.
2
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

1. SafetyPrecautions
1.1. General Guidelines
1. Whenservicing, observetheoriginal leaddress. Ifashortcircuit
isfound, replace all parts whichhavebeenoverheatedor
damagedbytheshortcircuit.
2. Afterservicing, see toitthat all theprotectivedevices suchas
insulation barriers, insulation papersshieldsareproperlyinstalled.
3. Afterservicing, make thefollowing leakagecurrentchecks to
preventthecustomerfrombeing exposedtoshock hazards.
1.2. Touch-CurrentCheck
1. Plug theACcorddirectlyintotheACoutlet. Donotuse an
isolation transformerforthischeck.
2. Connect ameasuring networkfortouchcurrents betweeneach
exposedmetallicparton theset and agood earthground suchas
awaterpipe, as showninFigure1.
3. Use LeakageCurrentTester(Simpson 228 orequivalent) to
measurethepotential across themeasuring network.
4. Check eachexposedmetallicpart, and measurethevoltageat
eachpoint.
5. ReservetheACplug intheACoutlet and repeat eachoftheabove
measure.
6. Thepotential at anypoint(TOUGHCURRENT)expressedas
voltageU1and U2, does notexceedthefollowing values:
Fora. c.:U1=35 V(peak) and U2=0.35 V(peak);
Ford. c.:U1=1.0V,
Note:
ThelimitvalueofU2=0.35 V (peak)for a. c. and U1=1.0V for d. c. correspond tothevalues 0.7
mA(peak)a. c. and 2.0mAd. c.
ThelimitvalueU1=35 V (peak)for a. c. correspond tothevalue70 mA(peak)a. c. for
frequencies greaterthan100 kHz.
3
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

7. Incase ameasurementisoutofthelimits specified, thereisa
possibilityofashock hazard, and theequipmentshouldbe
repairedand recheckedbeforeitisreturnedtothecustomer.
Figure1
2. Prevention of ElectroStaticDischarge (ESD) to
ElectrostaticallySensitive(ES) Devices
Somesemiconductor (solidstate)devices canbedamagedeasilybystaticelectricity. Such
componentscommonlyarecalledElectrostaticallySensitive (ES)Devices. Examples oftypical
ES devices areintegratedcircuitsand somefield-effecttransistorsand semiconductor "chip"
components. Thefollowing techniques shouldbeusedtohelpreduce theincidence of
componentdamagecausedbyelectro staticdischarge(ESD).
1. Immediatelybeforehandling anysemiconductorcomponentor
semiconductor-equippedassembly, drainoff anyESDon your
bodybytouching aknownearthground. Alternatively, obtainand
wearacommerciallyavailabledischarging ESDwrist strap,
whichshouldberemovedforpotential shock reasonspriorto
applying powertotheunitundertest.
2. Afterremoving anelectrical assemblyequippedwithES devices,
place theassemblyon aconductivesurface suchas alminumfoil,
topreventelectrostaticchargebuildup orexposureofthe
assembly.
3. Use onlyagrounded-tipsoldering iron tosolderorunsolderES
4
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

devices.
4. Use onlyananti-staticsolderremoval device. Somesolder
removal devices notclassifiedas "anti-static(ESDprotected)"can
generate electrical chargesufficienttodamageES devices.
5. Donotuse freon-propelledchemicals. These cangenerate
electrical charges sufficienttodamageES devices.
6. DonotremoveareplacementES device fromits protective
packageuntil immediatelybeforeyou arereadytoinstall it. (Most
replacementES devices arepackagedwithleadselectrically
shortedtogetherbyconductivefoam, alminumfoil or
comparableconductivematerial).
7. Immediatelybeforeremoving theprotectivematerial fromthe
leadsofareplacementES device, touchtheprotectivematerial to
thechassisorcircuitassemblyintowhichthedevice will be
installed.
Caution
Besureno powerisappliedtothechassisorcircuit, and observe
all othersafetyprecautions.
8. Minimizebodilymotionswhenhandling unpackagedreplacement
ES devices. (Otherwise hamless motion suchas thebrushing
togetherofyourclothes fabricorthelifting ofyourfootfroma
carpetedfloorcangenerate staticelectricity(ESD)sufficient
todamageanES device).
3. About lead free solder(PbF)
Note:Leadislistedas (Pb)intheperiodictableofelements.
Intheinformation below, Pbwill refertoLeadsolder, and PbF will refertoLeadFree Solder.
TheLeadFree Solderusedinour manufacturing process and discussedbelowis(Sn+Ag+Cu).
ThatisTin(Sn), Silver(Ag)and (Cu)although othertypes areavailable.
Thismodel uses PbFree solderinit’smanufactureduetoenvironmental conservation issues.
For service and repairwork, we’dsuggesttheuse ofPbfree solderas well, although Pbsolder
may beused.
PCBsmanufacturedusing leadfree solderwill have thePbF withinaleafSymbol
5
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

stampedon theback ofPCB.
Caution
-Pbfree solderhas ahighermelting pointthanstandardsolder.
Typicallythemelting pointis50 ~70 ~F(30~40~C)higher. Please
use ahigh temperaturesoldering iron and set itto700 ±20 ~F(370
±10 ~C).
-Pbfree solderwill tend tosplashwhenheatedtoo high (about1100
~For600~C).
Ifyou must use Pbsolder, please completelyremoveall ofthePb
free solderon thepinsorsolderarea beforeapplying Pbsolder. If
thisisnotpractical, besuretoheat thePbfree solderuntil itmelts,
beforeapplying Pbsolder.
-Afterapplying PbF soldertodoublelayeredboards, please check
thecomponentsideforexcess solderwhichmayflow ontothe
opposite side. (see figurebelow)
SuggestedPbfree solder
Thereareseveral kindsofPbfree solderavailablefor purchase. Thisproductuses Sn+Ag+Cu
(tin, silver, copper)solder. However, Sn+Cu(tin, copper), Sn+Zn+Bi (tin, zinc, bismuth)soldercan
alsobeused.
6
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

4. Self Check
1. Self-Check isusedtoautomaticallycheck thebuslines and
hexadecimal codeoftheTVset.
2. To get intotheSelf-Check modepress theDown( )
button on thecustomercontrolsat thefrontoftheset, at thesame
timepressing theRecall button on theremote control, andthe
screenwill show :
IftheCCU portshave beencheckedand found tobeincorrector notlocatedthen“--”will appear
inplace of“O.K.”.
7
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com

5. ChasisBoardLayout
8
PDFcreated withpdfFactoryProtrialversion www.pdffactory.com