Panasonic PV 20DF62 User manual

ORDERNO. MKE0204602C1
B6,B22
TV/DVDCombination
PV-20DF62 / PV-27DF62 / PV-27DF62-K
SPECIFICATIONS

2002 Matsushita Kotobuki Electronics Industries LTD. All rights
reserved. Unauthorizedcopying and distribution isaviolation of
law.
1. SAFETY PRECAUTIONS
1.1. GENERALGUIDELINES
1. IMPORTANTSAFETY NOTICE
Therearespecial components usedinthisequipmentwhichare
importantfor safety. These parts aremarkedbyinthe
SchematicDiagrams, CircuitBoard Layout, ExplodedViewsand
ReplacementParts List. Itisessential that these critical parts
shouldbereplacedwithmanufacturer’sspecifiedparts toprevent
X-RADIATION, shock, fire, or otherhazards. Donotmodifythe
original design withoutpermission ofmanufacturer.
2. AnIsolation Transformershouldalwaysbeusedduring the
servicing ofCombination TV/DVDwhose chassisisnotisolated
from theACpowerline. Use atransformerofadequate power
rating as thisprotects thetechnicianfrom accidents resulting in
personal injuryfrom electrical shocks. Itwill alsoprotect
Combination TV/DVDfrom being damagedbyaccidental shorting
that mayoccur during servicing.
3. Whenservicing, observetheoriginal leaddress, especiallythe
leaddress inthehigh voltagecircuits. Ifashortcircuitisfound,
replace all parts whichhavebeenoverheatedor damagedbythe
shortcircuit.
4. Afterservicing, see toitthat all theprotectivedevices suchas
insulation barriers, insulation papers, shield, and isolation R-C
combinationsareproperlyinstalled.
5. Beforeturning thereceiveron, measuretheresistance betweenB
+lineand chassisground. Connect (-) sideofanohmmetertothe

B+ lines, and (+) sidetochassisground. Eachlineshouldhave
moreresistance thanspecified, as follows:
(For model with20 inchCRT)
B+ Line
Minimum Resistance
115 V
1k (Coldchassisground)
28 V
180 (Coldchassisground)
220 V
1k (Coldchassisground)
(For model with27 inchCRT)
B+ Line
Minimum Resistance
140 V
1k (Coldchassisground)
28 V
180 (Coldchassisground)
220 V
1k (Coldchassisground)
6. WhentheTV set isnotusedfor along period oftime, unplug the
powercord from theACoutlet.
7. Potentials, as high as 34.5kV arepresentwhenthisTV set isin
operation. Operation oftheTV set withouttherearcoverinvolves
thedangerofashock hazard from theTV set powersupply.
Servicing shouldnotbeattemptedbyanyonewho isnot
thoroughlyfamiliarwiththeprecautionsnecessarywhenworking
on high voltageequipment. Alwaysdischargetheanodeofthe
picturetubetotheCRTground ofreceiverbeforehandling the
tube.
8. Afterservicing make thefollowing leakagecurrentchecks to
preventthecustomerfrom being exposedtoshock hazards.
1.2. LEAKAGE CURRENTCOLDCHECK

1. Unplug theACcord and connect ajumperbetweenthetwo
prongson theplug.
2. For physicallyoperatedpowerswitches, turn poweron.
Otherwise skipstep2.
3. Measuretheresistance value, withanohmmeter, betweenthe
jumperedACplug and eachexposedmetalliccabinet parton the
receiver, suchas screwheads, connectors, etc. Whenthe
exposedmetallicparthas areturn pathtothechassis, the
reading shouldbebetween1M and 12 M . Whentheexposed
metal does nothaveareturn pathtothechassis, thereading
must beinfinity.
1.3. LEAKAGE CURRENTHOTCHECK
1. Plug theACcord directlyintotheACoutlet.
Donotuse aisolation transformerfor thischeck.
2. Connect a1.5k , 10 Wresistor, inparallel witha0.15 F
capacitor, betweeneachexposedmetallicparton theset and a
good earthground, as showninFigure1.
3. Use anACvoltmeter, with1k /V or moresensitivity, tomeasure
thepotential across theresistor.
4. Check eachexposedmetallicpart, and measurethevoltageat
eachpoint.
5. Reverse theACplug intheACoutlet and repeat eachoftheabove
measurements.
6. Thepotential at anypointshouldnotexceed0.75 V RMS.
Aleakagecurrenttester(Simpson Model 229 equivalent) maybe
usedtomake thehotchecks. Leakagecurrentmust notexceed1/
2mA. Incase ameasurementisoutsideofthelimits specified,
thereisapossibilityofshock hazard, and thereceivershouldbe
repairedand recheckedbeforeitisreturnedtothecustomer.
Figure 1

2. X-RADIATION
WARNING:
1. Thepotential source ofX-Radiation inTV sets istheHigh Voltage
section and thepicturetube.
2. Whenusing apicturetubetest fixturefor service, ensurethat the
fixtureiscapableofhandling 34.5kV withoutcausing X-Radiation.
NOTE:
Itisimportanttouse anaccurate periodicallycalibratedhigh
voltagemeter.
1. Reduce thebrightness tominimum.
2. Set theSERVICE switchtoSERVICE .
3. MeasuretheHigh Voltage. Themeterreading shouldindicate 32.5
kV±2.0kV.
Ifthemeterindication isoutoftolerance, immediate service and
correction isrequiredtopreventthepossibilityofpremature
componentfailure.
4. TopreventanX-Radiation possibly, itisessential touse the
specifiedpicturetube.
2.1. HORIZONTALOSCILLATORDISABLE CIRCUITTEST
SERVICEWARNING:
The testmustbe made as a final check before setis returnedto the customer.
CONFIRMATION OF X-RAYMOVEMENT
1. Turn off TV set.
2. Connect thecircuitbelowbetweenTP553 and TP554 on theTV
MainC.B.A. Figure 2