Panasonic TX-28CK1 User manual

ColourTelevision
TX-28CK1
TX-25CK1
Z8Chassis
SPECIFICATION
(Informationinbrackets {} refersto modelTX-25CK1)
Power Source: 220-240V a.c.,50Hz
Power Consumption: 76W{76W}
Stand-byPower
Consumption: 0,9W{0,9W}
Aerial Impedance: 75 unbalanced, Coaxial Type
ReceivingSystem: PALI,PAL-525/60
M.NTSC
NTSC(AVonly)
Receiving Channels: UHFE21-E68
IntermediateFrequency:
Video/Audio
Video38,9MHz
Audio32,9MHz
32,35MHz(NICAM)
Colour34,47MHz
Terminals:
AV1INVideo(21 pin)1V p-p75
Audio (21 pin)500mVrms10k
RGB (21pin)0,7V p-p 75
AV1OUTVideo(21 pin)1V p-p75
Audio (21 pin)500mVrms1k
RCAINVideo1V p-p75
RCAINAudio500mVrms10k
High Voltage: 28kV± 1kV{28kV± 1kV}
PictureTube: A66ECF50X0466cm
{A59EEQ15X9759cm}
AudioOutput: 2x10W(M.P.O.)
2x5W(R.M.S.)
8Impedance
Headphones: 8Impedance
3,5mm
Accessories
supplied: RemoteControl
2xR6(UM3)Batteries
T.V. Stand TS2800
Dimensions:
Height:580mm{538mm}
Width:646mm{580mm}
Depth:471mm{442,5mm}
Net weight: 33kg{27kg}
Specifications aresubject tochange without notice.
Weights and dimensionsshownare approximate.
NOTE:ThisServiceManual should beusedinconjunction with
theZ8Technicalguide.
ORDERNo. 00-SM-001
PanasonicCS(U.K. )Ltd.
WILLOUGHBYROAD,
BRACKNELL,
BERKS,
RG12 8FT.

CONTENTS
SAFETYPRECAUTIONS..........................................................................................................................................................2
SERVICE HINTS.......................................................................................................................................................................3
ADJUSTMENTPROCEDURE ANDFACTORYSETTINGS.....................................................................................................4
WAVEFORMPATTERN TABLE...............................................................................................................................................5
ALIGNMENTSETTINGS...........................................................................................................................................................6
BLOCK DIAGRAMS..................................................................................................................................................................7
PARTS LOCATION.................................................................................................................................................................10
REPLACEMENTPARTSLIST................................................................................................................................................11
SCHEMATICDIAGRAMS.......................................................................................................................................................17
CONDUCTORVIEWS.............................................................................................................................................................20
SAFETYPRECAUTIONS
GENERALGUIDELINES
1.It isadvisabletoinsertan isolation transformerinthe
a.c.supplybeforeservicingahot chassis.
2.When servicing,observe the original leaddressinthe
highvoltagecircuits. If ashort circuitisfound, replace
all partsthat havebeenoverheatedordamagedby
theshort circuit.
3.After servicing,seethatalltheprotective devices
such as insulationbarriers,insulationpapers,shields
andisolationR-Ccombinationsarecorrectly
installed.
4.When thereceiverisnotbeingused foralongperiod
of time,unplugthepowercordfromthea.c.outlet.
5.Potentialsas high as 29kV{29kV}arepresentwhen
thisreceiverisinoperation. Operationofthereceiver
without therearcover involvesthe dangerofashock
hazardfromthereceiver power supply. Servicing
shouldnot beattemptedbyanyonewhoisnot
familiarwiththeprecautionsnecessary whenworking
onhighvoltageequipment. Alwaysdischargethe
anodeofthetube.
6.After servicingmake the followingleakage current
checkstopreventthecustomerfrombeing exposed
toshockhazard.
LEAKAGECURRENTCOLDCHECK
1.Unplugthea.c.cordandconnectajumper between
thetwoprongsoftheplug.
2.Turnonthereceiver spowerswitch.
3.Measuretheresistance valuewithan ohmmeter,
betweenthejumpered a.c. plug andeachexposed
metalliccabinet part on the receiver, suchas screw
heads, aerials,connectors, control shaftsetc.When
theexposedmetallicpart hasareturnpathtothe
chassis, the readingshouldbe between4Mohmand
20Mohm.Whenthe exposedmetaldoesnothavea
returnpathtothe chassis,thereadingmustbe
infinite.
LEAKAGECURRENTHOTCHECK
1.Plugthea.c.corddirectlyintothea.c. outlet. Donot
useanisolationtransformer forthischeck.
2.Connect a2k 10Wresistorinseries withan
exposedmetallicpart onthereceiverandanearth,
such asawaterpipe.
3.Usean a.c.voltmeterwithhighimpedanceto
measurethepotential acrosstheresistor.
4.Check eachexposed metallicpartand check the
voltageateachpoint.
5.Reversethea.c. plug atthe outletandrepeat eachof
theabove measurements.
6.Thepotentialat anypointshouldnotexceed
1,4Vrms.Incaseameasurementisoutside the limits
specified, thereisapossibilityofashockhazard, and
thereceivershouldbe repairedandrecheckedbefore
it isreturnedtothe customer.
X-RADIATIONWARNING
1.ThepotentialsourcesofX-Radiation inTVsetsare
thehighvoltagesection andthepicturetube.
2.When usingapicturetube testjigforservice,ensure
thatthe jigiscapableof handling 29kV{29kV}
without causingX-Radiation.
NOTE: It isimportant touseanaccurateperiodically
calibrated high voltage meter.
1.Set thebrightnesstominimum.
2.Measurethehighvoltage. Themetershouldindicate.
TX-28CK1, TX-25CK128kV±1kV.
If themeterindicationisoutof tolerance,immediate
serviceand correctionisrequiredtoprevent the possibility
of prematurecomponentfailure.
3.Toprevent any X-Radiationpossibility,it isessential
tousethe specified tube.
HOTCHECKCIRCUIT
a.c.VOLTMETER
WATERPIPE
(EARTH)
TOINSTRUMENT'SEXPOSED
METALLICPARTS Fig. 1.
2k 10Watts

SERVICE HINTS
Howto removetherearcover
1.Remove the5screwsasshownin
Fig.2.
LOCATION OFCONTROLS
Fig.3.
SCREWS
E-BOARD FOCUS SCREEN
Y
-BOARD

ADJUSTMENT PROCEDURE
Item / PreparationAdjustments
+BSET-UP
1.ReceiveaGreyscalesignal.
2.Setthecontrols:-
BrightnessMinimum
ContrastMinimum
VolumeMinimum
1.Confirmthefollowingvoltages.
TPE1 3,3±0,3V TPE13 -13 ±1V
TPE2 195±10VTPE14 27,5±1,5V
TPE3 13,5±1VTPE15 28±1,5V
TPE4 10±1VTPE16 11,5±1V
TPE8 5±0,3V TPE17 8±1V
TPE11 147±10VTPE18 5±0,3V
CUTOFF / Ug2Adjustment
1.Receive aGreyscalesignal.
2.Degauss thetubeexternally.
3.Set theTVintoServiceMode1.
4.Select Ug2Test.
SetContrastonmaximum,set Brightnesson center, switchon
AV mode.
EnterService mode.Set Sub-Brightness to31.Select Ug2
Test. Press "+"and adjustscreenVr till sharpverticallineis
visibleand LEDswitchesoff. Thenreducescreen Vrtill LED is
justswitchedon (pin6ofconnector E1mustbeconnectedto
GND).
Note:Tosetup !whitebalance!firstsetup "Cutoff!registerto8.Thensetup "high-light!withthehelpof "drive!registers.
Finish setting-up of "Low-light!withthehelpof !Cut-off!register.
Carryoutsetting-up of!whitebalance!inavailableTV systems(PAL,SECAM).
FACTORYSETTINGS
Toreturncustomersettingstofactory settingsand clearowner IDofallinformationinputby the customer, enter Self-Check
mode. Pressthedown (-/v) buttonon thecustomercontrolsatthe frontof theTV set, at the sametimepressingthe STATUS
buttononthe remotecontrol. To exit Self Check,switchoff theTVsetatthe powerbutton.
ServiceAids
Toaidintheservice of ourcurrentchassisthereareanumberofServiceAidswhichhavebeen madeavailable.
LUCI interfacekit(Linked Utility Computer Interface)
Part number:TZS6EZ002
Thiscontainsinterface and cablesfor connecting TV serviceconnector and aPC aswell asdiagnosticsoftware.Asnew
modelsareintroducedupgrade softwarewill becomeavailable.
VICI (Visual Interactive Computer Information)
TheseC.D.'scontainmultimediadocumentationprovidingquickaccess toserviceinformation.
Part No. TZS7EZ006, TZS7EZ005,TZS8EZ001 &TZS9EZ001
1.ServiceManuals
2.InstructionBooks
3.Technical Information
TASMIN (Technically Advanced System for Multimedia Interactive Notes)
Aswell asprovidingafirststeptowardsmoreinteractive trainingthisproduct also achievesquick accesstoTechnical
Information.
OPTION124{OPTION124}
OPTION200{OPTION200}
NOTE: Self Checkshouldonl
y
beusedwhen refurbishin
g
theTV setand notdurin
g
normal re
p
airwork.

WAVEFORMPATTERN TABLE
VERT-OUT
IC601
Pin 21
20ms
1V
IC451
Pin 2 VERT-DRIVE
20ms
50V
IC451
Pin 3
V
FLB
20ms
28
,
4V
H-OUT
IC601
Pin 33
64 s
3V
EW-OUT
IC701
Pin 5
64 s
20V
H-PULSE
BaseQ501
64 s
1
,
4V
IC701
Pin 8 HFLB
64 s
2V
FBI/SCOIC601
Pin 34
64 s
5,7V
SCL
IC601
Pin 2
47 s
5V
B-OUT
IC601
Pin53
64 s
2,7V
R-OUT
IC601
Pin 51
64 s
2
,
7V
G-OUT
IC601
Pin 52
64 s
2
,
7V
IC601
Pin 38 VIDEO OUT
64 s
2,7V

ALIGNMENT SETTINGS
ToaccessServiceModeselect programposition99andsetsharpnesstominimum.
Press "MUTE!button on remotecontrolandat thesametimepressthe"V"button on thecustomercontrolsatthefront of
theTV,thiswill place the TVsetintoServiceMode.
Press / buttonstostep up/ downthroughthefunctions.
Press +/- buttonstoalterthefunctionvalues.
Press "STR!buttonon thecustomercontrolsatthe front oftheTVafter eachadjustmenthasbeenmadetostorethe
requiredvalues.
Toexit ServiceModepress "N!button.
Alignment Function Setting indication
Note: All settingvaluesareapproximate Settings /Special features
1. Cut off(Ug2)LEDOn/OffLED tobejustOn
2. VerticalslopeV-SLO32Optimumsetting
3. Vert. AmplitudeV-AMP33Optimumsetting.
4. VerticalshiftV-POS 43Optimumsetting.
5. HorizontalshiftH-CTR31Optimumsetting.
6. HorizontalparallelogramH-PAR34Optimumsetting.
7. HorizontalbowH-BOW31Optimumsetting.
8. R- CutR #CUT8Optimumsetting.
9. G- CutG #CUT8Optimumsetting.
10.R- DriveR-DRV 31Optimumsetting.
11.G-DriveG-DRV 31Optimumsetting.
12.B- DriveB- DR 31Optimumsetting.
13.AGCAGC 08Optimumsetting.
14.Sub ColourS- COL20Optimumsetting.
15.Sub BrightnessS- BRI 31Optimumsetting.
16. HorizontalWidthEW #WD34Optimumsetting.
17.EWparabolaEW #PR 32Optimumsetting.
18. EWUppercornersEW #UC32Optimumsetting.
19. EWLower cornersEW #LC33Optimumsetting.
20. EWTrapezoidEW #TP 36Optimumsetting.
Input remotecode "FA"followedbykey 5(14 hex)orpress "Statusbutton"on remotecontrol
(numericalkeys0-6tochange value, TV/AVbuttontostoreonremotecontrol):
OptionByte 1Option BytesTable
Bit No.VALUEFUNCTIONS
00Frenchmodel 0
1
NO
YES
10Irishmodel 0
1
NO
YES
21NICAMenabled 0
1
NO
YES
30A2stereoenabled 0
1
NO
YES
40Tunermanufacturer 0
1
MACO
ALPS
51CRT 0
1
21"
25",28"
60Q-link enabled 0
1
NO
YES
OptionByte- 2OptionByteTable
BitNo.ValueFunctions
00
10
20
30
40
50
60

PARTSLOCATION
NOTE:
The numbersontheexplodedviewbelowrefertothe
mechanical sectionofthe ReplacementPartsList
21
12
3
22
19
17
18
1
7
46
5
8
14
20
9
2
15
11
13
16
10

SCHEMATICDIAGRAMSFOR MODELS
TX-28CK1, TX-25CK1
(Z8CHASSIS)
NOTE
1.RESISTOR
All resistorsarecarbon¼Wresistor, unless markedotherwise.
Unit ofresistance isOHM( ) (k=1,000,M=1,000,000)
2.CAPACITORS
All capacitorsareceramic50V unless markedotherwise.
Unit ofcapacitance is Funlessotherwisestated.
3.COIL
Unit ofinductanceis H,unless otherwisestated.
4.TESTPOINT
Test PointPosition
5.EARTHSYMBOL
ChassisEarth(Cold)
LineEarth(Hot)
6.VOLTAGE MEASUREMENT
Voltageismeasuredby ad.c.voltmeter.
Measurement conditionsareas follows:
Powersourcea.c.220V-240V,50Hz
ReceivingSignalColour Barsignal(RF)
All customercontrolsMaximumposition
7.
Indicatesthe Videosignal path
Indicatesthe Audiosignal path
Theseschematicdiagramsarethelatestat timeof printingandaresubject tochangewithoutnotice.
REMARKS
a.Donot touch the hot part, orthehotandcoldpartsatthe sametime, asyouareliabletoashock hazard.
b.Donotshortcircuit the hot and coldcircuitsaselectricalcomponentsmay bedamaged.
c.Donotconnectaninstrument,suchasan oscilloscope, tothehot andcoldcircuitssimultaneouslyasthismay cause
fusefailure.Connecttheearthof the instrumentstotheearthconnectionof thecircuit being measured.
d.Makesuretodisconnect thepower plugbeforeremovingthechassis.
NOTE
1.ThePower SupplyCircuit containsacircuit area,whichusesaseparatepowersupplytoisolatethe earthconnection.
Thecircuit isdefinedby HOTandCOLDindicationsintheschematicdiagram. All circuits, except the Power Circuit, are
COLD.
IMPORTANTSAFETYNOTICE
Componentsidentifiedbymarkhavespecial characteristics
importantforsafety.Whenreplacingany of thesecomponents,use
onlymanufacturers'specifiedparts.

CONDUCTORVIEWSFORMODELSTX-28CK1, TX-25CK1
E-BOARD TNP8EE011
TRAN'SDIODESD852B4
Q253B4D002E4D853B4
Q255B5D003E4D1101B5
Q401E4D260B4D1104A1
Q402E4D261B4D1106A2
Q501D3D262B4D1107A3
Q551D1D401E4D1201A3
Q601D6D402E3D1202A3
Q602 A2D403E4D1205A3
Q603E6D501C4D3101E5
Q606E3D502D4
Q701D4D510E3I.C.'S
Q702D3D551E3IC251B4
Q751C3D552D2IC451E3
Q752C2D553E2IC601D6
Q753D2D554E3IC701C4
Q851B3D555E3IC702C4
Q852B3D556D1IC801C2
Q1101D5D557D1IC802C3
Q1102A3D559E2IC851D4
Q1107A2D601E6IC852D4
Q1109A3D603E6IC1102D5
Q1110A3D606E6IC1103B5
Q1201B3D607E3IC1104A2
Q1204A3D701C3IC1105B6
Q2001B7D702D3IC1201A3
Q2002B7D703D4IC1202A3
Q2003B7D704D3IC2001B5
Q2004B7D705D3
Q3104E4D706D4T.P.'S
D707D4TP1A3
D751C3TP2E2
D752C2TP3E3
D753C2TP4E3
D754C3TP5B7
D755C2TP6E3
D801E7TP8A3
D802E7TP10B7
D803C2TP13E3
D804C3TP14B4
D805B3TP15B3
D806B3TP16C4
D808C2TP17D4
D809C2TP18D4
D810B3TP19E3
D811B2TP20E7
D812C2TP21D5
D813B2TP22E2
D814C3TPE11B1
D851C4
1234567
A
B
C
D
E
20