Color Television Troubleshooting

253 Pages·1986·14.63 MB·English

by  R. Vijay

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FirstE dition-I986
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@)B .P.B. PUBLTCATIONS
3?6,O ld LajPatR ai Market, DELHI-6
8/1, Ritchie Street,M ount Road, MADRAS-2
4-3-269G, iriraj Lane, Bank Street,H YDERABAD-l
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Publishebdy MaoishJ -ainfo l B'P.B.P ubticaticinrnr d printcdb v him at
RcnuP rinters,D elhi.
Preface
ColourT elevisionw asi ntroducedin our countryd uringA siad-82
and a largen umbero f manufactureras re now mauufacturingc olour
televisionr eceivers.T he responsibilityo f maintainingt hesef alls on
the servicet echniciansa lreadyi n the trade.
This book hasb eenw ritten to provide comprehensivaen d up to
date informationo n servicingc olour televisionr eceivers.
The book which is in two parts includes the basic principles of
colour televisiona nd their servicing. The priucipleso f colour tele'
vision have been discusseidn the first part of the book in simple
language. The secondp art provides detailedi nformationo n the cir-
cuits and servicingo f colour televisionr eceivers.
T'hef unctionso f the variouss tageso f a colour l.clevisionr eceiver
have been discussedi n chapter1 . The operatingc ontrolsa nd their
corrects ettingh aveb eend iscusseidn the next chapter.
Colour televisionr eceiversh ave four indications-raster, black
ancl white picture, colour and sound. Locatingt he defectives tage/
sectionf rom abnornalitiesi n these have been discussedin chapter'
three. The instrumentsn eeded for colour TV servicinga nd their
applicationsh aveb eend iscusseidn next two chapters.
Functionso f variouss tagest,h eir circuits,v ariousd efectsa nd step-
by-stept roubleshootingh aveb eend iscusseidn the next ten chapters.
Adjustmento f servicingc ontrolsi s an important part of servicing
of colour TV receiversT. his hasb eend iscusseidn chapters ixteen. A
lv
resumeo f fault finding techniquess,a fetyp recautionsa nd somea ctual
caseh istoiiesa reg iveni n the lastc hapter.
The commonf aultsn oticedin somel -V rcceiveras nclp itl voltages
of somes electeIdc s usedi n various modelso f colour TV rcccive|s
areg iveni n the two appendicesT.h is is followed by a glossaryo f
commont ermsu sedi n colourt elevision'
Cornpletec ircuitso f four selectcdln odclso f colour TV reccivet's
haveb eeni ncludedin the book for readyr cfereuce'
i
, tIlF lrookj s expectedto be usefult o all those interesteidn colour
televisiona nd their servicing. .w,i
R.c . vijay f
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i,t 'rl r rr
(L- ontents
'I'elevision
,- , PAR'I-I Colour Principles
.
. 'ttt -,.' ,. : i,,.
\:
a1t - 1. Introduction ,.1i1 .. t, t,,,!\ 3
Historicabl ackgroundw, lty coloul, requilerncnts
,I of colourt elevision-Compatibility.C olours ignal,
bandwidtha nd interference.
2. ColourF undamentals , ;f. 7
Colour,w hitel ight,v iewingo t' objccts'ancclo lour.'
''''
Prirnary colours, characteristicso f colour, repie-
, ductiono f colouri n colourt elevision.
't :, , 1' .
' r\
3. BasicC olourT elevision.systems 13
' '
Basicf edtiirest rf colour televisions yscf nrs,r estlic!,-
,
ing the bandwidth.
'
a. PAL Colour TelevisionS ystem 18
Main featureso f PAL Colour f'elevision systeur;
bandwiclihcr6 nsiderationqsu,a dlaturem odulatie!,,,,r.
i r'
choice of subcarrier frequency,s wingingb urst,, .,'
completec olours ignala nd colours tandards.
5. ColourP ictureT ube .' ..'.!i r , ii ...,,, 32
Basicf eatures,s. hadow-maskc olour picture tube,
precision;in-linq(P If) picture tube 'and the Trini: : i
tfOn. )t:. );::tt.
Chapter PagO
6. Mairr Featureso f Colour l'elevision Jl
Colour f'undamentals,c ompatibility, colour sigrtitls
and colour TV systemsS. pecial features-'luminancc
signal, chroma signal, quadrature modulation,
phasea lterationb y line, subcarrierb ursts, complete
signal and souud signal. Colour TV receivers.
PART-II Servicing
._\
'Ielevision
1. Working of a Colour Receiver 19
Main sections--Turter,V ideo IF, Sound section,
Video amplifier,C hrona section,C olour signal out- *r
I
put section, Pioture tube stage, Sweep sectiou and ,
Power suPPlY'
2. Operating Controls in Colour Television Receivers 63
On-off switch, fine-tuning cotltrol, brightness collt-
rol, contrast coutrol, colour control, tone control
anclv ertical hold. Proper adjustmento f operating
controls in colour TV sets.
3. Locating the Faulty Stage from Fault Syrnptons 69
Principleso f locatirrgt he faulty stage from lault
symptoms. Trouble symptom chart-Black arld
white defectsa nd Colour defects'
4. Colour TV Testinga nd ServicingIn struntents--I
tt5
Multimeters
The commonm ultimeterp, recautiottws hileu singa
multimeter. Digital multimeter-principle,a dvatt-
tages,d isadvantageasn d applications.
-II
5. ColourT V Testinga ndS ervicingIn struments
ColourP attern Generators 94
Colour patterng eneratorst,e st signals-black attd
white patternsa nd colour patterns.A pplicationso f
variousP atterns.
vll
Page
Chapter'
6. PorverS UPPII'--I l0{f
RequirementTs.r arrsistorre gulatedp ower supplies
-principles and operatiott.P o\t'ers upplvc ircuit
usedi n Koreanc olout'TV t'eceive'rsI)' efccts and
ontputv oltager diustment.
109
7. PowerS uPPIY-It
Switchingm ode power strppliesS' witchingr egu-
lators, switchingc onvertors,s witchingr egulators
ancls witchingm odep owers uppliesS. witchedm ode
powers upplyc ircuitu sed in ITT Colour TV re-
ceiversD. efects,t roubleshootinagn d replacenrent
of trausistores tc.
118
8. VidcoI F Section
Functionsc, ircuit,f unctionso f variousc omponents'
Defectsa nd troubleshooting.
128
9. SoundS ection
Frtnctionc, ircuits,d efectsa ntlt roubleshooting'
134
10. VideoA mplifier
Function,c ircuits-v ideoa mplifierc ircuits usedi n
Westonc olourT V receiverC etron-llla nd Korean
colourT V receiveSr amsung'D efectsa nd trouble-
shooting.
pc
147
I 11. ChromaS ection-I
.a* Systemuss edi n chroma section,f unctions'B lock
B
' diagram and functions of various sub-sections--
t Chroma amplifier,D elay line decoder,U andV
signald emodulatorsS, ub-carrierre generatorB, urst-
gateM, ultivibratorP, AL switcha ndM atrix section'
160
12. ChromaS ection-Il
Circuits-circuito f chroma sectionu sed in CTV
. receiverM odel 'samsung'-functionso f various
snb-sectionins this cirquit. Defects nn{ troqblo-
sllooting.
viii
chapter .
Page
13. Colour SignatO utputS tages '" , ll|
Colours ignalo utpttt stilgcs- circuits.r cliuslment
defectsa nclt r:oubleshoin o.tc .
14. PictureT ubeS tage lg3
Picture tube-d.c. voltages,d eflectiona sse.mbly,
circuitsd, efectsa nd troubleshooting.
: Y
15. SweepS ection $2
Main parts- functionso f eachp art, circuit,d efects
and troubleshooting. i: .. ../.i )..1. .) ..;
16. ServicingC ontrolsoT hcir Arljustmenat nd neiiragietiiing 202
the PictureT ube
Servicingc ontrols'andth eii,adjustrhent*Hor.,osc.
control, Verticalo scillatorc ontr6l,,H Eight control,
Focusc ontrol, AGC delay control,A FT contrql.
Colours ub-carriecro ntrol,p urity adjustmen, fG rey
scale adjustment and Convergencea djustment,
Demagnetisintgh e picturet ube. !'r"" ' ; I
; :i;,
17, GeneralP roqedureS, afgtyp regautionsa ndS orne.Gase 214
Histories, .. , .
Preliminary, fault location, safety precantions,
e
handling the picture tube,p revention of X-ray
radiation.C aseh jstories.
lppehaix
, . .'
'in
I. Conrmon Defects noticed Koiesn ColourilV
Receivers. I
II. DC voltagesa t the pins of variousI C,s useciln Colour
TV Receit,ers.
231
Gfossary Commont er;nsu sedi n colour televi,sion 23g
Errlte 244
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PAFTT I
(Color.err
lFelerrisiorr
Proin.reiples
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