'l liltr I lll b, \ r It ll I I I ll \ I I t l' FirstE dition-I986 _/'-b .*-4, :-\. @)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 i : tr- 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 " 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 it PAFTT I (Color.err lFelerrisiorr Proin.reiples l l