Cam Nang Sua Chua Tivi Va Dau Video Split 3 8452

8/3/2019 Cam Nang Sua Chua Tivi Va Dau Video Split 3 8452

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D4 Y mach nhan dang ngang (!thng b O mau theo dong)

IDENT hoat d<)ng chung voi hai M mau,

BURST AMP l . B . mach tach xung dhng ~ mau (Ide) mau

cua hai M NTSC/P AL. Con xung nhan dang ngang thuOc MSECAM thl dltQc tach ra tit mach IDENT do mach C¢ng hltoog

IC d~t 0 chan 24 (REF SECAM), NMc lal: trong giAi rnA mau

NTSC/P AL phai co mach tao song mang mAu (3,58MHz hoac

4,43MHz) d6 dua vao cac b O Hoan di~u mau nham phuc 'b.hi

hai hi~u 56 mau R - Y, B . Y; dAy lA nhi~m vu cua mach

CHROMA VCO (dao d<)ng mau VCO) heat d(mg vOl. thn sli

dltQc a:n dinh Mi hai thach anh XTAL 3, 58 va 4,43 XTAL.

Nhung cac dao dQng nay mu6n cd de>d'n dinh pba va thn sli

tb~t virng phai nM d~n IJlI;lChAPC, ma APC la mach so pha

2 thn sli BURST va dao dQng mAu. '

Mach CN 'di'{!ukhie'n vi~ cung', c4p' sOng mang mau tuy-'

theo tin hi~u thu vllo lAPAL, NTSC hay SECAM. N6u la PALl

NTSC no ~ cung c4p sOng chub 3,58 h~c 4,43MHz cho

cac ~ HOOn Di~ mAu NTSC/P AL ~ng thbi lam tA t mach

SECAM DEMOD de' cho hai hi~u s6 mAu R - Y, B • Y ctia

PALJNTSC qua d6 xu!(t hi4)n ~ chan 2 vA 64.

Vi~c di'{!ukhie'n cho TV tl,t dQng l a m vi~ Web nghi theo

tin hi4)u mAu dltQc mQt h~ th6ng mach thuc hi4)n. H~ th6ng

n a y hoat dOng xu(t phat tit xung nhan dang h~ mau (xung

dhng b Q mau), bao gbm cac mach: SYSTEM CONTROL

SECAM lNG, FORCED STANDARD. Xung xoa ngang vao

chan 35 thao mach cho SYSTEM CONTROL hoat dQng wi

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xung nhan dang t« IDE NT, sau do di~u kh.i~n FORCED

S~ANDAD de cu6i cling, tuy theo M,mau do xung nh$.n d~ng

tao dQng, cho 1"3 tai chan 10 (SW1 ), chan 11 (SW2 ) hoac

chan 21 (SW3 ) m{jt xung dieu khien M mau (PAL, NTSC

hoac SECAM) dua vao mach SYSTEM LOGIC ben trong mQt

Ie khac (nhu TA8615).

Nhttng xung nhan dang t« dAu ma co? DO l a do khi ta

chon M mau voi nut SYSTEM r o i chon DBi dt1 co tin hi~u

dgn CHROMA AMP, t u do xu4t hi~n xung nhan dang, Cu6i

cung tit SYSTEM LOGIC cac kh6i mach trong TV dttQe d~t

dung chec nang.

Nhirng kh6i mach khac trong TA8659AN Is:

- DE-EMP - SW : giAi nhan tlin cao trong cae hi~u s o mau

va dong rna cac hi~u 56 mau cho ra a chan 2 va chan 64.

- CHAMP: Mach ghirn mue DC (ph1,1hhi di~n DC) cho cac

hi~u 86 mau,

- HA LF TONE: DA y 1A ki4u mach ENHANCER lam n6i

b . $ . t dt).ctlnh ril!ng cUa c a e hi~u s6 mAu, cho U't qua hlnh mausA c s a o h a n .

_ TV I EXT SW : Chuyen mach d~ dung tin hi~u R, B,

-G cua TV hay tit b€m ngaoi dua vll.o (EXT R chin 47, EXT

G chan 49, EXT B chan 51) v a duqc dieu k h i e n Mi. mach

TX CaNT.

71 .



\-16 - IDA 4~55

GtAI MA PAL - SECAM -NTSe

'fit trtU:lCta chi g$.p hai h,* m¢t IC gh li mA 2 M mau,

Mung chua- g$.p mQt IC g ia i ma. ma cA ba M mau NTSC -PAL - SECAM. BA y g ib ta xet d~n m"t IC ~ bi~t nhu ~y .

D6 ' l8. IC TDA4555. IC nAy thuc hi~n Ult cA nhttng chile

nang cUa b Q g i 8 . . i ma da M PAL - SECAM- NTSC. cd tM dung

vbi di~n khu V\tc 60Hz va song mang phu 3, 58 MHz hoac

di~n 50Hz vbi song mang phu 4,43 MHz (hlnh 66).

1) PnAN T i N HltU CHROMA;

· Khuech d~ tin hi~u chroma co t\t ki~m lQi sU§t ACC

· Mach to ki~m lqi - suIt (ACC)

· Chon lAy mAu BURST cua PAL .

· fin xu4t chroma qua day t~ 64,uS

· Cae mach han bien cua ltenh tI'\tc ti~p vA ltenh t~(SECAM).

· ChUY~D mach SECAM.

2) PHAN HoAN - DltU:

· Hai mach hoan - di~u vuang pha (SECAM).

· Hai mach hoan - di~u dbng - b Q (PAL - NTSC)· LQc son mang phv. cOD s6t 1~ bAn trong.

· CAc mach dAi - nMn hao - tAn (lam giA.mtAn cao ) cua

SECAM.

· M~h ghim muc dan SEC~.

· Thng xu«t m m a R - Y va B - Y vOi ~ cAt mA.u (tri.t

mau).

3)P I I A N NH!N D~G.

· T 1 . t - d¢ng chuydn h6a mu chu~ hOf.t dQng bAng each

72



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-SECAM

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don chon,

· Mach uu tien eho PALlSECAM. '

· Mach giao hoan ddi tieu ch~n· Cac mach nhan dang cho PAL! XECAM va NTSC.

FLIP - FlOP PAL va SECAM.

· Nhan dang SEeAM thea dong, manh (ngang, d9C) hoac

ph6i hop c A hai.

· Dao dQng thach anh tlin - .s6 g§:p dOi, mach PLL va chia

tlin song chuan,

· Mach chlnh TINT cua NTSC.

4.TRiNH .11)' NH~N D~G

Vi~ tim chon tiliu chuan th\iC hi~n hAng mQt giao hoan

ehuyen d6i tai nhirng nga ra 25 - 26 - 27 - 28. Ml;lt each tulD.

t\i bAng di~n th~.

· Chi nhirng mach lien quan d6n tieu chuM thu nhan m mhoat d¢ng. .

GHI cHO Xung dang thap (sand castle: lliu cat) d6n tU

cac mach d?lp.g bQ ngang va dQC co ba mite: - Xda ngang va

doc: tit 2V dE!n 3V. - Xung dong (ngang): 4 d~n 5V: - Chon

BURST: tit 8 dE!n 9V.

Day 1ft tin hi~u htic:mg da.n, cho phep thuc hi~n ba each

nhan dang SECAM TREN CHAN 23.

5. cAc N G O RA :

Tfn hi(iu R - Y ra tai chliu 1, bien d~ dlnh - d6i - dlnh

khoang 1,05 VPPi va. t~n chliu 3 tin hi~u (B - Y) bien dQkhoAng 1,33Vpp.

Cac tin hi~u hi~u s6 mau nhy dl1c;:1cua vao b\i XU - LY

.. - HiNH (videoprocessor ).

74



'!'ran dAy cbl gibi thi~u t6ng quat d~ ditm cUa IC TDA

4555 dt khi g$p tJi!,n mQt kitu may n ao do (PHILIPS,

THOM SON ...) cae ~c6 tht'db dQC h(qc . ~ d~ SU:R chUa.

Khi cd tac dQng cUa 1phirn, vi tinh ~ n6i dung vbi phim

HAnM d6 di~u khitn theo chuc nAng y~u chu, vA hi~n rachile nang do tIfln bang hi~n s6.

Vi tinh can dgn 2 ngu'On DC + 5V, nguon cho truong hop

hoat dQng blnh thttbng V I\ mQt ngu'On cho Stadby.

Vi xu If dU:QchU:CfngdAn hO i mot thach anh 4MHz (QR27)

m a c ~ chan 1 (hlnh vl:l), thach anh chi ph6i m<)t mach d'Ong

hb 'bl!n trong rna thn s6 chi co 1 kHz (chan 3,do mach chia

tlin tit tlln s6 thach anh, dtn s6 d'Ong hb su dung cho hoat

dQng cua b Q nho ~n ngoai,

M6i chiic nang cua may thu hlnh, b Q vi -xu If phai nh(ln

mt)t xung mac cao (RESET").

B¢ nhCf ban ngoai bao gbm: mOt EEPROM 128 OCTAL,

mQt giSi rnA dia chi, m¢t thanh ghi, me)t mach ki6m tra trlnh

de) (Controle de sequence) mQt mach giao ti«p xu«t (interface)

di'Au khitn nhung chuc nllng khac nhau.

75



1"17 - ,uPC 1382C

ICAMTHANH

Trong IC nAy, c6 nhirng mach HQ,nbi~n, lee thOng ha (LPI<'

: Low Pass Filer ) tach sOng Am (FM DET), HltlJ:ng dAn AF

hay khuech d~ di~n th~ Am thn v a ATT (mach suy g iAm , tri~t

4.P Am).

Tin hieu SIF trubc khi vao chAn 14, phAi qua lQCceamaic

CF301. Tit chAn'14, S. IF v8.o HQ,n bj~n, qua lQCthOng hQ.,

qua tach song Am qua mach tri~ 4.P Am (ra chAn 5 v80 l Q . i

chan 4), sau cUng vao mach khukh . ~ AF rl)i thea chAn

2 ra mach khu&h d~ cOng s u « t ~n ngoli. TR301, TR302

lA cap tranzisto elmg SUItt rap cascade, cOng sdt khoAng 1WATT.

Chan 1 nhan ngubn tit du:bng + 12V qua dQCcao th~ R307

• C304. ChAn n6i masse.

ChAn 9 va chan 10 mac g6m lip di~n CF302 5,5 MHz cho

mach tach sOng Am (FM DET).

.Chan 2 dua AF ra phan cOng su4t Mn ngoAi.

GhAn 8 m a c IIlQ.Chdi~u chinh Am lU:c;1ng_OLUME (VRa).



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9.3Y 2.1 2.2

~4 2. 6.2

.uPC1382C

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NGO RE AM THANH

Tin hi~u ra 4li chan 12 cila IC TA 7607 hi loai tin hi~utoan phan da. d1.1!Jchoan di~u ~ mach VIDEO DET, gtlm hai

thanh phan:

. Tin hi~u hlnh h6n hop d1.1c;:1Cl)'8 vao mach ti~n khuech

dai hlnh TRZ02,203 .

. Trung tAn til!ng S. IF 5,5 MHz h~c 6,5 MHz tuy thea

ti~u chuan. N~u thu BIG thl:- SIF la 5,5 MHz (38,9 -33, 4MHz ).

-Thu D IK thl SiF la 6,5 MHz (38,9MHz - 32,4MHz -

6,5MHz) d1.1!Jcdua vao cha:u HI cU a board PWC 1269 (board

ddi thn cia SIF). Trong board nay cd mQt mach ddt tAn ~m

da o dQng 12MHz dung t ranzito TR351. T352 l 8 . bifn th€ dao

dQng 12MHz. T351 10. bi€n th€ n~p 6kHz va T353 10. bie' n -

th€ ra 5,5MHz.

S J F 10.dao dQng 12MHz trOn sOng_d~ cho 5,5MHz ghEip ' tit

board na y vao chan 14 cua IC pPC1382C.



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1-18.: rc TA7607 APM~, du cUng mOt I~ may ed k~ C«u ,chfnh t~n ngu~n

t.Acgi6ng nhau, nhttng ki«u NEC 14T43LSK so v(Ji cac ki~uNEC 14T470MP, 14T470DMP co m¢t s6 chi tilrt don giAn hdn

vi no chi dung cho 4 M .trong hie hai may Ida dung cho 5

M . May nay dung ch o PAL vA SECAM v6i 4 tiAu chu4n BIG

v a D/K (quen gQ i la -4 M ).

ToAn b O may gbm 5 IC chinh sau dAy:

TA 7607AP (IC20l): Video IF , Video DET, AFT DET, AGe(IF , RF ), 080 t r u : nhi~u (Noise Inverter,>.Trung tAn blob

, IA.38,9 MHz, trung tlnAm ra kh6i TUNER la 33,4 MHt (BIG)

h~c 32 4MHz_ DJK_r~l\ t v$y tru n g tln ti~ng S.IF vQo phln

Am thanh la 5,5 MHz (BIG) hO$CD/K IA 6,5MHz. Mu6n th u

duqc cA hai I~ S.IF nay, nguai!ta dung mQt dao dQng 12MHz

t~n sOng vtri 6,5MHz dd dua vao phln Am thanh d$t sAn5,5 MHz cho S. IF AMP. M~ d6i tln nAy ed vA riAng·t~n

IUQc db (PWC 1296 - 'SND CONY PWB ). NgO v a o cUa Ie

nAy (chan 1 v a 16) IAb¢ la c SAW (FL201). NgO ra pbAn thanh

2 dU <1n g (tit chan 10):

Duemg tin - hi~u hinh: truce khi vao tranzito Ti'An khukh

d~ Hlnh TR202 (Video Pre-Amp). TR203 tin hi~u h6n hophlnh phAi qua M y Am thanh 6,5 MHz hoa c 5,5MHz. Ndu dUng

mach LC tbl dAy hl m¢t mach ~ng huObg song song LC cong

h\1Cfng tren 5,5 MHz hoac 6,5 MHz d~t trAn dUCJngdi cua

tfn hi~u S.IF d€ can tfn hi~u nAy khOng cho IQt qua phln

hinh anh, vi t6ng trlf r4t cao (cue dai). 06 la trong m ay ca ,may

mmngttC1ita du n g lQC ceramic (gbm a p di~n), nhu trubng

hop nay la hai IQCCF201 va CF202 (CF : Ceramic Filtor ).

(Hlnh ve ngll ~ Am thanh hlnh anh).



1-19 - HA11247 - GUii maNTSC

IC giAi ma. NTSC HAll247 (cllu 4W bsn trong) .

. Trong thCri khoAng cO xung BURST (DAm b th~m sau

xung xda ngang), nd dua xung BURS.T v a o ~ tAch sOng

APC (tach pha) - APC DET. Di~n th'DC t\l ch lnh tA n cho

dao dQng chu«n (mach. 3,58 MHz a se hO$C 4,43 M Hz aSC)

do APC DET cung cllp vdi chan 17 ed tv . lQCDC nay.Tin hi~u chroma tit 2ND AMP ra ~ chan 14 rbi do 1 t\1

bsn ngo8.i dira dIn chAn 16 dli vAGba mach tach sOng d"Ong

~ R - Y -, B - Y , G -- Y . Hai m ach n ly em u nh$ .n d l 1 < 1 C

cao tan 3,58MHz hoac 4,43_MHz tit mach dao d~ng chwin ase ,



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con mach tach song mau G - Y thl do ph6i hcp cua hOOmach

Ida -0 chan 5 mac 2 thach anh tao sOng chu4n tuong u-ng.~bn chan 6 mac song song hai mach di~u ehlnh TINT (SAC

DIEU) ling v(:lihai ti~u chuan 3,58 MHz ho~ 4/43MHz CMn

8 nhan xung FLYBACJ( (ngang) tit mach SUA D~NG XUNG.

(Pulso Shaper ) ~i vao mach XUNG Mn trong IC, sau do

cung c a : p cho mach BURST d' tach ra Ide mau (dbng . b O

mau), dbng thai cung cap cho mach KILLER d€ mach nayph6i hQP vO i 2ND AMP lam nhiem V V - tri~t mau.

Vai khusch d/ili chrona th1.l nhit (1st AMP), con co di(!n

th~ ' IT, ! CHINH MAU ACC do mach tach sdng ACe (ACe DET)

vao di~u khi€n d€ di~u hoa dQ khuech dai, ACC DET la mc)t

mach tach sang dUbng batt (ki'u FM DET) nh.n xung BURST

roi cho ra xung dubng bao (dO rQng cO bi~n dQ li~n tuc) co

bien dQ thay dtii thea di~u ki~n tl'l!y'Ansdng v a dUQc IQC thltnh

Di(!n th~ DC d€ lam nhi~m v v - AC (Automatic Color Control)

. chan 10 m a c b o 1 9 C ACC.

ChAn 1 cho ra hi~u s6 m a l l B - Y.

ChAn 2 cho ra hi~u s6 mau R • Y, ChAn 3 d€ tr6ng (v i

kheng chn h'ly ra hi(!u - s6 mau G . Y trong ki€u may nay).Hai hi~u s6 mau B - Y v a R . Y ti~p tue v a o IC-TC4066.

IC nay IA contact PAL-NTSC (NTSC - PAL SW ), ni!u thu

h~ PAL s~ cho qua dn hi~u hi~u s6 mAu cUa PAL, n~t duang

NTSC lai;cOD khi

thu M NTSC no cho qua 2 hi~us6maucua NTSC, ngat dubng PAL.

83



1-20 - LA1357.

Tin hi(iu ttl TUNER qua IQCSAW rhi v8.o 2 chA.n 18,19.

Sau khusch dai trung tan hlnh, co hai mach tach song dIS

l;iy hai tin hil)u S. IF va h6n hop mau, Tin hi~u S. IF (4,5MHz)

do mach Tach sOng Pha (S. IF DET) trOn adng gifta hal tin

hi~u 58,75 MHz va 54f25MHz. Tin hi~u hInh mau h6n hlJp

tit V. DET qua ti~p V. AMP t'bi ra chan 11 T1r chan 11 tin

hil)u nay v80 cue B cua, TRIO! (nip ki'u Emitter Follower:

ganh ra tai eire E). TI02 la bay sOng A.m thanh, chAn S.IF

khOng cho van C \ 1 ' c B c U a TRIOI, T212 1 8 . dilSm that vA cungtit dilSn nay , tin hi~u ~ duc;Jcphan pMi cho Ie gilU ma. mau,cho Ta ch Xung D~ng - BO.

Trang LA1357, con cO mach Tri~t Nhi6u NC (Noise,

84



front Tliller ICIOI

lA I.JS7· 1 - h Q O f ~ A135 '1

Sif

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Canceller ), AGC cho Tuner v a cho V. IF . Con S. IF 14y ra

tai chan 5 dd vao chan 2 cua LA1320 sau khi qua IQCceramic

X352. IC 7193P-PAL

- PIS SIGNAL SWITCH (contact tin hi~u PAL/SECAM).

Mach contact tin hi~u PIS khi g$p tin hieu cua M nao thl

mach nAy cho tin hi~ cua M do qua, con cac phan t u thuec

M khac khOng hoat d¢ng.

- BUFFER PIS SWITCH (contact PIS d~m) la mach co 4

dhu vao (2 dhu vao cua M SECAM v a hai dhu vao cia h~

PAL tlng wi 2 hieu s6 mau R - Y , B - V), nhung chi co

2 dliu ra chung cho hai hieu 86 mau R - Y. va B - Y (co

th€ dung mac h rC:1iMng 4 diode, rn A khOng din phAi dung

tay d~ thay d6"i contact co khi).

Nhu da. bii!t, cac may thu hlnh mau chi khac nhau (j b¢

giBi ma. MAy thu PAL thltC:1ngco phAn giAi rnA PAL (phanmau PAL) blng m¢t IC gQi]A PAL DEMOD (Holm Di~u PAL).

Hlnh 8 la m¢t PAL DEMOD vbi nhitng thAnh pU.n C«u tao

ben trong nhu sau:

• BP AMP (Bandpass Amp) : Khu&:h dJ;li bang thong,

• BURST GATE: Cdng Brust, tllc l A mach tach 1 1 1 y xung

dbng b(I mau PAL.

• ACC DET (Automatic Color Control Detector ): TAch sdng

t\i chinh mau

• ACC AMP: Khusch dI(liACC(khu&:h I4i DC d~ cung c«p

DC t\i di~u lc;li cho BP AMP).

• PAL SW : Contact PAL hay CHUY~ MACH PAL dung

dd dAo pha sOng chuan cho mach R - Y DEMOD. PAL SW

do FF (OP· FLOP) hll{jng dan.

• KILLER + ID DET.: Tri~t mau + Tach sdng Nh$n dang

(1«y xung dllbng bao cua BURST).

86



• AFP (Automatic Prequency - Phase Control) DET:

Tach s6ng Pha (gi6ng nhu AFC trong quet ngang).

• PASE CONT: Dmu khi~n pha.

• CW asc (Continuous WAVE Oscillator: Dao d¢ng 4W

s6ng li~n tuc, tue Iil khOng bUfn di~u) hay REF OSC lA da o

d¢ng Chulin 4,43Me.

ID AMP: Khuech dai nhan dang

• KILLER AMP: KD Tri~t mau,

COLOR CONTROL : Di~u khien mau (d(i baa hoa).

AFT Dung IC cua RCA CA3064

Truoc h~t, clin xem chi ti~t clu tao ~n trong cua Ie nAy

(hlnh trung }4 25' ghm: mach khuech dai bang ~ng, tachs6ng, m¢t khuech dl;liDC va mach ON AP dung diode Zener,

cd tM' thay th~ CJlO IC q .rang 27 la mach sit dung,

Chan 7 nhan tin hi~u r o i dua vao cue n~n Q2, chan 8 di€mchung n6i ra masse. Tin hieu IF ra tai cue E-Q2 d~n BQ3

rl'li duc;1ckhuech d~ d ' Ql va den sa cap Ll, L2, L3 cna bien

the phAn bi~t. C\ic B-Ql duoc ghim mire DC bAng ngul)n 6ntip Zener IQ c bd'i tl,l O,OOl,uF.· '

Cac ngO ra cua bien th~ phan bi$t dtlc;1Cap vao cac cue

B cUa Q7 v a Q13, mOt phan cua hai b O khu~b - d~ vi phAn

Q7-Q8 vA Q12 - Q13. Tuy the Q8 vA Q12 cung duc;1Cghim

muc DC bl1i cung mOt nguon cung clp eho Q1. Nhung l~b

pha IF nhieu hay it sli lam C1, C2 thay d6i di~n the nap dU«1e(C1, C2 tri s6 nhieu hay it tuy theo dO lfi!ch pba ella IF ).

Cae dong nap nAy cung clp tit phan tntllc den. '



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T~O XUNG QUEr NGANG vA QUEr DOC.

Do m~t dao ·d~mg th€ ki€m VCO vClithach anh cd tlin 86gA:p32 Illn tln s6 ngang mtic ~ chan 37, ttlc l:l mach 32fH

OSC. 'I'an s6 32 fH n~y S 4 ! ! ! dung chung cho quet ngang w .quet dQC,nhung phai qua mach chia tln (H-V IL). TIt mach

chia tln xung quet vao ~h sua dl.lD.gxung (VERT) dt$ cho

ra xung quet dQCtal chan 29. Cling tit mach chia tln,cho

ra xung quet ngang dua vM mach khu~ d(li H.OUT d€ choxung l}gang ra CI chan 39. TA7ti98AP - PAL NTSC

1-21 - Chuy&n rnaen dao dQng VCO 3.85 MHz, 4,43 MHz

M1,Ic dich cU a CHUY£N MACH dao dMg 3,85 MHz

4,43MHz IS.khi TV hoat dOng ven tin hiQu NTSC ch~n

3,5BMHz,thl dao dOng VCO 18m vi~ vbi th\lch anh 3,5BMHzmAc Mn ngoAi IC,W khi TV thu tin hiQu PAL (hO$CNTSC4,43

MHz) VCO lam vitc vCliXTAL 4,43.

Nguylm tAc chung coo msch My 18dung di(!n th€ (tl,t d(mg)

di~u khi~n contact di~n t u (tranzi to hO$C diode) d~ n6i ma c h

thach anh thich hep Mn ngoM v C I i VCO ~n trong IC .

. Kbi thu tin hi~u NTSC3,58MHz, contact b v j . tri ON, nendubng dAy 3 co muc thap OV: GND), trong Inc dUClng dAy

2 co miic cao + I2V lam eho diode D305 din d~ n6i thach

anh X301 xu6ng masse qua t1,lC3IS (trong hie D306 M) lam

eho VCO hoat dOng v6i. 3,58MHz .

. Khi thu tin hi~u PAL (NTSC 4,43 MHz), contact S701-1C

CI vi tri OFF " n~n dubng a co mdc tha:p 6V ca o 12V trong

hie dttbng 2 eo mde tMp lam eho D306 thOng w . n6i machthach anh X302 xu6ng masse ngang qua t\1 CalS (ddi vl1i AC)

89



1-;;2 , _ LA 7600 chua toan b9 phan mau NTSC - 3,58 MHz. Ngoai

cac mach phal c6 cua NTSC DECODER nhu 1st CHROMA

2ND CHORMA AP M, ACC, 3,5SMHz OSC, KILLER ,

TINT, PHASE, APC, CHROMA OUTPUT AMP con co mach:

· VIDEO AMP: Khuech dai hlnh (tuc r a khuech dl;li V).

· COLOR TEMPERATURE CONTROL: Ki~m soat nhi~t

d O mao.

· PEAK CLIP! BLANKING: clt ngon (san bAng [email protected] e ; . )

v a tao xung x6a.

·PULSE SHAFER: Slia dang xung (cho phu hQp nhu cau),· DC LEVEL SETTING: Dinh muc De (cbo cac loai xung,

tin hi~u khac ) ,

· PEDESTAL CLAMPING: Ghim mdc den (duy - trl macden).PICTURE QUALITY CONTROL: Kilm aoAt ch«t I t t c ; J n g , - -

binb.

Hinh trang [email protected] mach ben ngoru eua IC LA7600. Tinhi~u b6n ho p mau tit ti~n kbukh dl;li hlnh (dilm TP12 trAn

h1QC - dh thttbng g(kp) trulfc khi v80 chAn 1, pbAi qua ~ lQC

bang thOng (L202 - C222- R201). TU chAn 1, chroma vao

khu~ d~ sAc thu: nha:t Hat Chroma Amp), va ti~p 2nd

Chroma Amp rhi dua thAng l~n phln Chroma Output Amp.

Phan nay baa gam nhieu chile nang' (Hoan Dieu mau, Matti.n, Xu~t mau) d€ culli cilng cho ra ba bi~u 56 mau {) ba

chan 12, 13, 14.

Tin hi~u Y thea dUCJng 1301 (day trti 0,7 .uS) , di~u chinh

CONTRAST (VR303), vao chan 25, qua t n t l C h ki@.'msoat chat

lucng hlnh, qua mach Pedestal Clamping DC level Setting (d~t

muc DC), Peak Clip Blanking ( cAt ngon xung xda) va cullicung vao VIDEO AMP dt ra tI;li chAn 15.

Tit chan 15, tin hi~u Y vao cue B cU a TR302 (KHuECH

DAr HINH 2), ra tai cue E cua TR302 dl vao ba tAng RED

OUTPUT, GREEN OUTPUT, BLUE OUTPUT.



00

SU BCONTRAST'

Moch bin ngodi ella IC LA 7600 SANYO C.UA3

91



H. DRIVE - H. OUTPUT - HV POCUS BOOST VOLTAGE

Mach hlnh nc n6i ti~p mach hinh Ida cua IC LA 7800. Xung

quet ngang do H. OSC ra 4 U chAn 3 rhi ghep trl,tc ti~p v80

cue B tranzi to huang dan ngang (TR 451) ngang qua cu¢n

L451, T451 IA bi~n th~ lien II;\CHOT (H.Drive transfonner).Tranzito xuAt ngang (Tr 452) duqc ch~ 4Lo d$Cbi~t d~ lam

c a nhiem vu DAMPER . Dong rang cua quet ngang dua vao

cu¢n l~h ngang (H.)'UKE) lAy 4U Cl,i'cC ella TR452, Diode

D453 nAn xung ngang thAnh di~n th~ tang cuemg (Boost

voltage: Bbi ap), Cling thea m.)t each nhu v$.y,co tMm2".ngubn

DC khac Ia:y t~n bien th~ phi Mi (PLIBACK): Xung ngangla:y is hai chan 9 va 12 do D454 nan thanh nguon: 12V vA

D455 - D456 - C476 min ki~u tAng dOi di~n th~ d~ co ngubn

70V cung clp cho mach cOng suAt doc nip thea kitu OTL

(Output tranzito less ). D~ Y cae di~n trlJ R478, R473, R483·, . . . . . _

la loei di~n trlJ cau chi da' baa v~ cac mach nan di~n khi co

cham mach trong may.Kh6i maca n a n di~n 4 L i cao th~ cung c«p ba ngubn di~n

th~ Ibn cho esc C1/.ecua den hinh mau: HV cho ducng C1jc ,

FOCUS cho cue Mi tu va SCRREEN cho cl1c gia U S c (lubi

man). Cac di~n the nay emu dut:;lcdi'riu chinh dung mdc.

Cuen thtl ca:p (chan I, chan 2) cua FLYBACK dung d'

lAy dil[jn th~ xung ngang lam nguon d6t tim den blnh. Chan

10 (d6i vbi masse Ia chAn 12) 14yxung ngang dua vao tranzisto

nan dang xung (pulse shaper ) cung c«p cho IC mau NTSC

(LA7600).

Qua nhtrng trlnh bay trin; ta can luu y cac di«fm sau dAy

d«f ap dung vao vil[ic chuy«fn h~ khi can, d6 1A:

- La:y xung x6a doe: TI;li chan 9 cua IC LA 7800

- lAy ngubn DC 12V - lAy sau b(I lee C468 - R477 d@'

vao board mau,

- Uy xung ngang (R. Pulse); Uy tai chan 9 hoac chan

10 cua quet ngang FLYBACK.92 -



CONTRe lL

/ f I L L E Rcc

~

6SC : s~

t. c

gI::

l,.d '". c ; ,_ 'O

~.

~

A c e

VIDIO

AMP

PEAK

CUP



1-23 - LA 1368 vA LA1369

. GIAI MA NTSC

TRang may SANYO Model CTP3467 da M mau: NTSC,

SECAM, PAL, IC LA1368 lam nhiem vu khu@Ch dai bAng

tMng v a khuech dai sang ch~n tit OSC ban ngoBi v a IC

LA1369 lam nhiem vu Hoan Dieu mau,

LA1368 (BANDPASS AMP + CW).

'I'ruoc khi tin hi~u chroma IF vao chan 5, phAi qua mQt

loat 4 tAng khuech d~i dung tranzito bsn ngoAi. Nhung 4

tranzito nay kMngghep true

ti~p tlnhieu vao chan 5

r n alai qua trung gian M th6ng contact (SYSTEM SW). Q2001,

Q2002, Q2003, va Q,2004 IA4 tranzito khui!ch d~ bAng thOng.

X2001, X2002 18 hai b e ; . lQCceramic (g6m ap di(ln) thay

the IQCLC thOng t huong , Tu c1,tCC . Q2004, tln hi~u pht\i

qua m¢t mang loc cu6i dg vao chan 5.

Tin hieu tit chan 5 vao CHROMA AMP (KD SAc ), saud6 vao tiep BURST GATE (c6'ng l6e), ~i qua mQt tlng

CHROMA AMP khac rna thn nay k€t hop v~i KILLER dg

lam nhism vu tri~t mau khi thu den trang.

Chan 8 nhan cao tAn chUM tit m¢t trong 2 mach 3,58MHz

OSC v a 4,43 MHz OSC tit ~n ngoai, do lA Q2041, Q2042

dung hai thach anh X2041 - 3,58Mc v a X204204,43MHz. Haimach OSC nay ghep song song nhau, vOi hai cue B cua n6

n6i qua ~ SYSTEM SW (contact M th6ng) di! dieu khi~n

hoat dOng co nghla la khi i1n nut NTSC 3,58 thl mach

3,58MHz OSC hoat dOng d~ dua cao tho nay v80 chan 8, con



Q2042 thl hi ngat, va ngircc Iai.

Mlilch ACC nh$n xung BURST tu BURST GATE, ngang

qua CW OSC 3,58 MHz, dl di~u hoa khueeh c4 i cbo CHROMAAMP tai c hA n 5 .

ChAn 10 mAc mach di~u chlnh ACCI KILLER (VR2021),

Wc III di~u chinh mac di~n thi! (My tit nguen +12V) d~ chondi~m lam vi~ chinh xac cho mach KILLER v a ACC, neu chinhsai s e t n 1 I : t t8.c dung hoac co tac dung xau.

ChAn 14 nM.n nguon tii!p di~n Vcc + 12V. Chan 13 ll!:y

ra cao thn 3,58 MHz hoac 4,43MHz (sang chulin) de dua tiep

vao tranzito khuech dai sang chuan: Neu nhan NTSC 4,43

thl Q2061 hoat dOng (4,43 MHz CW Amp), nErunh$n NTSC

3,58 thl Q2062 hoat dOng (3,58MHz CW AMP). Hai mach

tranzito nay ghep song song veti nhau, co mc)t ng6 v80 chung,

va hai ngCi ra chung cho hai song chuan:

· M¢t song chufn (3,58MHz hO$C4,43MHz) t11lc ti€p vao

Hoan di~u mau R: Y (R . Y DEMOD) ngang qua D2062 hoac

D2064 (veti 3,58MHz).

· M¢t sdng chuan l~h pha 90 d¢ (cua 3,59 MHz hoac

4,43MHz) ngang qua D2061 hoac D2063 truoe khi vao Hoan

di~u mau B . Y (B . Y DEMOD). Cac cu6n L2061, L2063tao dc) di pha 90 d¢ cho cac song ehu~n 3,58 h$ 4,43MHz.

· LA 1369 (NTSC DEMOO):

IC nay !W i la IC hoan di~u NTSC. Nhung ngo8i nhi~m V\1

hoan di~u mau, no eon chua nhirng mach khusch w p . Y (Y

AMP), xda (BLANKING), rna t~n G - Y (G - Y NATRIX ).

Nhu da biErtcac mach tach song cdn Mng (hay tach song

d3ng b~) can d~n hai tin hi~u: tin hi~u chroma chua hoan

di¢u (cd chua song mang phu) v a sOng chufn do dao dOng

trong may tao ra. 6 dAy ta nhan th4y:



BP,&.MP2

Q. 2002

3 ,58 M I'Iesc

Q,20+1

LA 1368 +

L.2001

8PAMP4a.200lt

310 l "F r o mPwlse.SH}l.pep

Chlo" ,.S ig "o.t



82K-

I·047

Giii ma M ' NTSC

.a t

12K~. 0 1

1 - - ; 1 .

mdfdfM1368 + LA1369 NTSC 8 . 1 . 1 : khai PAL~S

97



- Voi R - Y DEMOD: song chtra:n vao chan 12 va tin hi~u

chroma thl xuti:t phat tit chan 2 IC LA1368 di!n chan 9 cua

1 9 LA1369 rl,}i khusch dai tai R - Y CHROMA AMP truOc

khi vao R . Y DEMOD .

. Voi B . Y DEMOD: song chu'n vito chan 13 con tin hi~u

chroma tit chan 8 vao B . Y CHROMA AMP truClc khi vao

B - 'y DEMOD.

Sau khi hoan di~u, hai hi(!u s6 mau R . Y (ra t.(U chan

2) va B . Y (ra 0 chan 4) deu dua di!n phan contact PAL

. NTSC (dung IC) hoac tranzito NTSC SW « ( 1 dA y la Q272. NTSC SW .

Nhu v(iy mach G - Y MATRIX trong IC LA. 1369 khong

dung, Vi rna tr$n G - Y nam trong IC khac. 6 dAy , hai hieu

s6 rnau NTSC vao mach SYSTEM SW trong IC SECAM

DEMOD M51398, t~ chan 17 va chan 15.)

Vi LA 1369 khong dung mach Y AMP n~n chAn 5 b6 tr6ng,mach xoa (ELK) ciing kh6ng dung n@n 2 chan 6 va 7 n6i

masse.



SANYO C-14,U, chi c6 mQt M mau duy nh41 la NTSC

dung a nqi dja NMt c6 tUm ehu«U v~ s6 hang cua khung sang

la 525, s6 ban anh trong mQt giAy 18 GO,kh6 sang ctia mQtUnh truy~n hlnh IA 6MHz, sang mang Am bilfn ditu FM (di'Au

tho), trung thn l U n h 18 58,75 MHz, trung tho Am 1 8 . 54,25MHz

(tuc 18 trung tho ti~ng tha hai S. IF 18 4,5MHz).

May nay ~m 5 mac h IC sau day.

· LA5112 (lC 601): Di'Au hoa di~n thlf (t 'Sn lip) v a bao v ~

mach, LA7800(IC401): SYNC SEP, AFC, V.OSC; VERTDRIVER.

· LA1357 (IClOl): V,IF V. DET, SOUND IF DET, AGC,

AFT

· LA1320/ AN340 (lC 351): Sound IF AMP, SOUND DEP,

Audio Driver

· LA7600N (IC201), GiBi mA mau NTSC, cho ra ba hi~u

s6 mau R - Y . B - Y vA G - Y.

1-2( - LA 7800 - '-" rung ngang, xung dOC

99



LA 7800: SYNC SEP, AFC, V. OSC,V DRIVE, H.

OSC. V. BLK.IC nay cung ~p trong nhieu may thu hlnh da M . ChAn

14 nhan tin hi(iu hinh Mn hc;1P tit diifm TP 12 (Xem hlnh

ve) dif vaa SYNC SEP~ sau do vao AFC 1 I Mn trong IC. AFe

con nhan xung ngang mng cuavao 1 I chan 16 dif di~n th~

t l , l ' ch i nh thn s6 ph6i hQP vlri VR 451-H.HOLD v ao chA n adif di~u khien H. OSC. Di(in th~DC tU M e ra, qu chAn 0),lQC xong v80 chan (2).

Xung ngang do H. OSC tao ra Itly tit chAn (3) d~ dua d~n

cue B cua tranzito huang dAn ngang (TR451 - H. DRIVE)

(j bAn ngoAi (xem h ln h sau dAy )

Xung dbng b(I dQC tit SYNC SEF ra t4i chan (13) rbi vAo

mach deb, phAn 1 I ~n ngoti sau do t\l 0,015 din vAo chAn

(11) d~ di~u khl~n chu k Y cda V. OSC a : bAn trong. Xung

dQC do V . OSC tao ra dUc;1Cgbep wo c ung 11ic cho V DRIVE

v a V . BIK (V ertica l Blan k in g : xda dQC). Xun g x o o dQC tit V .

BLK ra tai ch~n 9 (may SANYO C - 1423 khOng S \ l : dung'

xung xoa dQC t4i c hAn 9 n@ n chan nay d l 1 ' tr6ng). Xung quet

dQC tit V. DRIVE ra t f , l . i chan 6 d~ dua d'n tlng xu«t dQC

1 I Mn ngoAi. Luu y chan 8 n6i vlJi cUQn I~ dQC tit tlng xua:t

dQC d~ ~ h'Oiti~p Am tAng cttttng cho dQ tuyfn tinh cda dbng

mng cua quyet dQC.

IC nay cd d$.c di~m thU$.n l¢ I A cd m seh d i'A u chinh tln

s6 ngang (H. HOLD) v a dQC (V HOLDj C J bA n n gOOi, nan ta

khOng cln sit:a d6i gi khi NTSC dung ngang lA 15750 Hz CHZ

rnA chuyt1n qua SECAM dung 15625MHz rung nhu dQC NTSC

60 MHz ~uyl1'n qua SECAM 50 MHz (chi cln di 'Au chinh 2

bifn tn) VR 401 vA VR451).



TRllf~rR

~----~~r-~--~.~+('1'rtJ6"

IJ,"·us

1", u: It:!o x/mg ngang I'dxung doe '

-'TOng tlvl NTSC SANYO C-NA3 (IA7SWV)

101



LA7800 . Tl;loxung ngang vA xung doc

lA7800

IC nAy cdng thOng dung trong cilc bi.;iumay SANYO khac

Quet dQC dung ~p tranzito cOng sua:t ban ngoAi TR402 ,

TR403. Con TP 401 IAHubng· Din doc cung c4p xung d Q C

cho cap cOng sua:t.

TIt chan 3 • IC LA7800 xung ngang ra Cl,tcB cia hubng

din ngang TR501 rbi d€n xua:t ngang TR502.

~n bi€n th~ xua:t ngang Ia:y xung phi - M i nAn, lQ C thAnh

eac cao th€ sau day: HV di~n thi! VOl cung c§pcho cue gia

tlSc, di~n thi! cung c«p cho Clf,eM i tu eua dim blnb mau.

. Ca e di~n tM' tAng cttC1ng: + 12V do D502 nAn, + 43V

cung c«p cho XUAT DQC do D501, + 150V do D503 nAn

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