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o^Tfp nrmr^rs REI/QX . B225

IiILIOF_CgNTEyTS page

1. GENERAL

1-1 Index of CO olayer co nt ro ls 1/i1*1* 1 General con tro ls 1/11*1*2 Special cont rols 1 2

1*1*3 Rear panel con nec to rs 1/3

2 . t REMO VAL OF ASSEHB LIES

2.1 Re mo vi ng the top cove r 2/12*2 Re mo vi ng tne side pane ls 2/12.3 Re mov in g the individual cir cui t boa rds 2/1

2*4 Rem ov in g the player mec han ism 2/125 Remov ing the display 2 2

2*6 Rem ovi ng the po^er t r ansf or mator 2/22*7 Re mov ing the drawer motor 2 1

2*8 Rem ov in g tne opera ting panel 2/3Z9 Rem ovi ng the guide rods 2/3

3* CIRCU IT DESCRIPTIONS

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eel /ox B 5

* T E S T P OI N TS t A D J U S T M E N T S OH E 2 2 5

4 i T e s t p o i n t s o n 6 2 2 ^ 4/14-l l Te s t p o i n t s o n S E RV O I P CB 1 ? 6 9 * 3 1 0 4/14 . 1 . 2 Te s t p o i n t s o n S E RV O 2 PCB 1 . 7 69 . 3 3 0 4/34 . 1 . 3 T e s t p o i n t s o n m i c r o p r o c e s s o r P CB 1 . 7 69 * 3 2 0 4/4

4 . 1 . 4 Te s t p o i n t s o n d e c o d e r PCB 1 . 7 69 . 3 0 0 4/64 . 1 . 5 Te s t p o i n t s o n 0 A C - P CB 1 . 7 69 . 2 6 0 4/84 2 A dj us t m e n t s o n C O p l a y e r B 2 2 5 4/94 . 2 . 1 A i d s 4/94 . 2 . 2 A l i g n i n g t h e p l a ye r m e c h a n i s m ? g e n e r a l 4/94*23 A dj us t i n g t he l a s e r c u r r e n t 4/94 . 2 . 4 A dj us t i n g t he b a l a n c e 4/94 Z* 5 A dj us t i n g t h e f o c u s g a i n 4 /1 04*2*6 C h e c k i n g t h e -t ing le a l i g n m e n t 4/1 04*2#7

A dj us t i n g t h e D C c o m p o n e n t o f t h e f o c u s s i g n a l 4/1 14 . 3 M e a s u r i n g t h e a udi .o d a t a 4/1 14 * 3 . 1 A i 4 s 4 / i 14*3#2 H a r m o n i c d i s t o r t i o n 4/1 14 . 3 . 3 O u t p u t l e ve l 4/1 14.3*4 F r e q u e n c y r e s p o n s e 4/1 14 . 3 . 5 C r o s s t a l k 4/1 24 . 3 . 6 S i g n a l - t o - n o i s e r a t i o * l i n e a r 4/1 24 . 3 . 7 S i g n a l - t o - n o i s e r a t i o ? we i g h t e d - ' 4/1 24 . 3 . 3 P ha s e l i n e a r i t y 4 /1 2

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R ^ / a x B225

1 .

1 . 1

G E N E R A L

I n d e x o f CD p l a y e r c o n t r o l s

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mruim R V O X B225

1 . 1 . 2 S p e c i a l c o n t r o l s

T h e c o n t r o l s in the l o w e r f r o n t - p a n e l s e c t i o n can ber o u g h l y d i v i d e d i n t o tw o f u n c t i o n g r o u p s : c o n t r o l sfo r s u p p l e m e n t a r y p l a y e r fu n c t i o n s , an d p r o g r a m m i n gc o n t r o l s .

A C o n t r o l s for s u p p l e m e n t a r y p l a y e r f u n c t i o n s

[9 ] P HONES

[ 1 0 ] V O L U M E +

[ 11 j V O L U M E -

[ 1 2 ] CA L T O N E *

1 3 ] A U T O S T O P

H e a d p h o n e s j a G k s o c k e t for he a d p h o n e s2 00 to 600 o h m s .I n c r e a s e s th e h e a d p h o n e s l e v e la n d th e l e v e l of the VA R I A B L E O U T P U T.D e c r e a s e s the h e a d p h o n e s l e v e la n d th e l e v e l of the VA R I A B L E O U T P U TTh i s c a l i b r a t i o n b u t t o n c o n n e c t s a

1 0 0 0 Hz c a l i b r a t i o n t o n e to theo u t p u t s so t h a t the r e c o r d i n g l e v e lo f a c o n n e c t e d t a p e d e c k can bea c c u r a t e l y a d j u s t e d . The 1000 HzC A L T ON E c o r r e s p o n d s to the m a x i m u mo u t p u t l e v e l . T hi s m a x i m u m l e v e li s s y s t e m - d e p e n d e n t and w i l l notbe e x c e e d e d e v e n by s h o r t p e a kp u l s e s .I n t e r r u p t s th e p l a y i n g s e q u e n c e

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mWU\n)MPd R ^ O X B225

[25j CURSOR

[26 J PROGRAM

A n y p o s i t i o n o n t h e d i s p l a y c a nbe e d i t e d by a p p r o a c hi n g i t wi t h t h ec u r s o r . NO TE ; i f t h e di s p l a y i s i nT IM E m o d e , t he c u r s o r m us t bea d va n c e d wi t h t h i s ke y i n o r d e r t oe n t e r t he s e c o n d s a ft e r t he mi n u t e s .Se t s t he p r o g r a m e n t r y mo d e . IfPLAY/NE XT [4J i s p r e s se d a f t e rt h e p r o g r a m e n t r i e s h a v e b e e nc o m p l e t e d, t he CD p l a y e r s t a r t s i nPROGRAM mo de ,If t h e CD p l a ye r i s t o b e s t a r t e di n n o r m a l mo d e a ft e r t h e p r o g r a me n t r i e s ha ve be e n c o m p l e t e d , p r e s sthe PROGRAM key [ 26 J a g a i n be fo r ePLAY/NEXT [4] .

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B ^ O X B225 SECTION 2/1

2 . REMOVAL OF ASSEMBLIES

I m p o r t a n t :D i s c o n n e c t t h e CD p l a y e r f r o m t he A C s u p p l y be fo r er e m o v i n g a n y p a r t s o f t he ho us i n g .. Fo r c e r t a i n wo r ki t i s n e c e s s a r y t o o p e n o r c l o s e t he d r a we r mo d ul e .T hi s c a n be d o n e m a n u a l l y wi t h o u t d a ma g i n g t he un i t .

2 . 1 R e mo v i n g t he t o p c o v e r

- U n f a s t e n fi v e s c r e w s [Aj o n t h e r e a r o f t he CD p l a y e r .- Wi t h dr a w c o ve r t o w a r d t he r e a r .

2 . 2 Re m o vi n g t h e s i de p a n e l s

- U n fa s t e n t w o s c r e w s o n e a c h s i de p a n e l i n o r de r t or e m o v e t h e m .

2 . 3 R e mo v i n g t he i n di v i dua l c i r c u i t bo a r d s

T he c i r c u i t b o a r d s a r e a c c e s s i b l e w he n t h e t o p c o ve ri s r e m o v e d (Se c t i o n 2 . 1 ) .

T he c i r c u i t b o a r d s 1 . 7 69 . 2 80 (D A C P C B ) , 1 . 7 69. 3 0 0(DECODER PCB ) , an d 1 .769 .33 0 (SERVO 2 PCB) can be pu l l edo u t o f t he i n t e r c o n n e c t i o n bo a r d a f t e r t he fi xi n g s c r e w s[ B ] ha v e be e n u n fa s t e n e d .

F o u r c o n n e c t o r s m u s t be de t a c h e d b e f o r e t h e PCB 1 . 769. 3 2 0

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'umrnm EMOK B225

D e t a c h t he s i x c o n n e c t o r s (s ee Fi g . 2 . 5 ) .Th e p l a y e r m e c h a n i s m c a n n o w be l i f t e d o u t o f t h ed r a w e r

SECTION 2/2

2 . 5 Re m o vi n g t h e di s p l a y

- Op e n t h e dr a w e r a n d un f a s t e n t w o s c r e w s [ Ej o n e a c hs i d e .

- U n fa s t e n c a b l e c l a m p [F] a n d de t a c h c o n n e c t o r o fc a b l e h a r n e s s . The d i s p l a y c a n n o w be l i f t e d o u tby c a r e f ul l y s l i di n g t he c a b l e ha r n e s s o u t b e l o wt h e p l a y e r m e c h a n i s m .

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2 . 8 Re m o vi n g t he o p e r a t i n g p a n e l

- Re m o ve t o p c o v e r (Se c t i o n 2 . 1 ) a n d s i de p a n e l s(Se c t i o n 2 . 2 ) .

- U n fa s t e n f o ur s c r e w s [Kj e a c h o n t h e t o p a n d t h ebo t t o m o f t he o p e r a t i n g p a n e l .

Ca r e ful l y wi t h dr a w o p e r a t i n g p a n e l ' fr o m t h e c h a s s i sa n d de t a c h t he c o n n e c t o r s .

2 - 9 R e mo v i n g t he g u i de r o d s

- Re m o ve t o p c o ve r (s e e Se c t i o n 2 . 1 ) .- Un f a s t e n t h e i n n e r r e t a i n i n g r i n g [ Lj ; t h e r o d c a n

n o w be p u l l e d o ut o f t he u n i t fr o m t h e r e a r .

N o t e : D o n o t l o s e t h e s m a l l O -r i n g t h a t c u s hi o n s t h ed r a w e r s t o p -

2 . 1 0 R e a s s e m b l y

T he CD p l a y e r i s r e a s s e m bl e d b y f o l l o wi n g t he d i s m a n t l i n gs t e p s i n t he r e v e r s e o r de r It i s a b s o l ut e l y e s s e n t i a l t o

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R ^ O X B225 SECTION 3/1

3 . C I R C U I T D E S C R I P T I O N S

3 . 1 S E RV O 1 P C B 1.769.310

T he f o l l o w i n g c i r c u i t s a r e i m p l e m e n t e d o n t h e S ER VO 1P C B ;- St a b i l i z a t i o n o f t h e s u p p l y v o l t a g e s- D r a w e r p o s i t i o n d e t e c t o r- F o c us c o n t r o l l o o p- D i s c mo t o r c o n t r o l l o o p

3 . 1 . 1 S t a b i l i z a t i o n o f t h e s up p l y v o l t a g e s

A l l s up p l y v o l t a g e s a r e s t a b i l i z e d by v o l t a g e c o n t r o l l e r s( IC 4 t o IC 9 , L M 3 1 7 / L M3 3 7 ) .T h e + 5 V s u p p l y ( + 5 V S T BY ) i s a l w a y s a v a i l a b l e . Its u p p l i e s t h e m i c r o p r o c e s s o r s y s t e m a n d t h e IR r e c e i v e re v e n w h e n t h e CD p l a y e r i s s w i t c h e d o f f ( s t a n d b y ).T he r e m a i n i n g s u p p l y v o l t a g e s a r e s w i t c h e d o n o r o ffby t h e m i c r o p r o c e s s o r w i t h t h e P S- OF F s i g n a l . Wh e n

t h e C D p l a y e r i s s w i t c h e d o f f , P S - OF F be c o m e s " H" ( +5 V )a n d t r a n s i s t o r s Q 9 a n d Q 1 0 b e c o m e c o n d uc t i v e( s t a t u r a t e d ) , c a u s i n g t h e +5 V a n d + 1 2 V s up p l y v o l t a g e st o d r o p t o a r e s i d u a l v o l t a g e o f 1 . 3 V. T he -7 V s u p p l yi s s w i t c h e d o f f t h r o u g h t he c i r c u i t R 3 8 , R 3 9 ? a n d Q8 ;t h e - 1 2 V s u p p l y vi a R 5 2 , R 5 4 , a n d Q l l ; a n d t h e - 1 7 Vs u p p l y vi a R 5 1 , R 5 3 f a n d Q 1 2 . T hi s p r e v e n t s t h e p o s i t i v es u p p l y v o l t a g e s f r o m b e c o m i n g n e g a t i v e . Th e v o l t a g ei s do u b l e d t h r o u g h d i o d e s D 1 5 , D 1 6 , D 1 7 a n d c a p a c i t o r sC 2 9 , C 3 0 # a n d t a k e n t o t h e v o l t a g e c o n t r o l l e r IC9 fo rt h e -1 7 V s u p p l y . D 1 8 p r o t e c t s t h e c o n t r o l l e r f r o ma n e xc e s s i v e d i r e c t - a x i s c o m p o n e n t o f t h e v o l t a g e .

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R ^ O X B225 SECTION 3/2

3 . 1 . 3 Fo c us c o n t r o l l o o p

The l e n s c a n b e mo v e d ve r t i c a l l y a n d i s de s i g n e d s i m i l a rt o t h e me c h a n i c a l s y s t e m o f a s p e a k e r . T he l e n s i sc o n t r o l l e d ma g n e t i c a l l y . The c o i l i s s t a t i o n a r y a n dt h e m a g n e t m o v e s . The f o c us e r r o r s i g n a l FOC-ERR i sf i r s t a m p l i f i e d (l e a d a m p l i f i e r I C2 a , R 3 , R 1 2 , R 1 6 ,R1 7 , C 3 , C 4) a n d s u bs e q ue n t l y t a k e n t o t h e c o n t r o l l i n ga m p l i f i e r ( lag a m p l i f i e r R l , R2 , R5, Rl l , R 15 , R29,R 3 0 , C2, C12, IC2b, Q6, Q7 a n d t h e i m p e d a n c e o f t hel e n s c o i l ) . In S TOP m o d e , t h e c o n t r o l l o o p i s i n t e r r u p t e dv i a Q l by t he s i g n a l F OC -0 {= H ) w hi c h me a n s t h a t n ou n n e c e s s a r y p o we r i s c o n s u me d b y t h e o u t p u t -a m p l i f i e r(Q6 and Ql).

T he s t a r t - u p c i r c u i t ( IC 1 , R 6 , R 7 ) a d ju s t s t h e fo c u s s i n gt o t h e r e fl e c t i v e l a ye r o f t h e c o m p a c t d i s c . The s i g n a l sF C- 1 a n d F C-2 a r e a l t e r n a t i n g i y s w i t c h e d t o " H" , c a us i n gt h e l e n s t o mo ve a l t e r n a t i n g i y u p o r d o wn . On c e t hec o r r e c t fo c u s ha s b e e n f o u n d, t h e s i g n a l FOC-NEG br i e fl yd r o p s t o " L" . The mi c r o p r o c e s s o r t h e n e n a bl e s t h e f o c usc o n t r o l l o o p (FOC-0, F C - 1 , a n d FC-2 - "L" .. Up to 12 ,000

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WmrMM R^I / OX B 2 2 5 S E C T I O N 3/3

3 . 2 M i c r o p r o c e s s o r PC B 1.769.320

T he m i c r o p r o c e s s o r s y s t e m a n d t h e d r a w e r c o n t r o l a r ei m p l e m e n t e d o n t he m i c r o p r o c e s s o r P CB 1 . 7 6 9= 3 2 0 .

3 . 2 . 1 M i c r o p r o c e s s o r s y s t e m

T he ma s t e r m i c r o p r o c e s s o r (M-ji P, I C2 ) s c a n s t h e k e y bo a r d(POO t o P G 5 , P 1 0 t o P 1 4 ) . The m i c r o p r o c e s s o r s y s t e m i s

r e s e t w h e n t h e L OA D ke y i s p r e s s e d . To e n a b l ed i f f e r e n t i a t i o n b e t w e e n a p o w e r fa i l u r e a n d a L OA D

c o m ma n d , P 1 5 o f t h e m a s t e r p r o c e s s o r i s a l s o p u l l e d t o"L fI i n c o n j u n c t i o n w i t h a L OA D c o m ma n d . Ca p a c i t o r C 1 2l a t c h e s t h i s c o n d i t i o n u n t i l P1 5 i s r e a d . T hi su n c o n v e n t i o n a l c i r c u i t a r r a n g e m e n t o f f e r s t h e a d va n t a g et h a t a R ES E T c o m ma n d c a n be i n i t i a t e d a t a n y t i m e b yp r e s s i n g t h e L OA D ke y i n t h e e v e n t t h a t t h e s y s t e mb e c o m e s b l o c k e d fo r a n y r e a s o n .T h e c o m m a n d s f r o m t h e IR r e c e i v e r o r t h e R E MO TE s o c k e ta r e r e a d t h r o u g h t h e i n t e r r u p t i n p u t o f t h e ma s t e rp r o c e s s o r . W he n a c o m m a n d a r r i v e s f r o m t h e I R r e m o t ec o n t r o l , t h e I R - RE C s i g n a l i s s w i t c h e d t o " LO W" f o ra p p r o x i m a t e l y o n e s e c o n d , c a u s i n g t h e LE D i n t h e IRr e c e i v e r w i n d o w t o t u r n o n (c o m ma n d a c k n o w l e d g m e n t ) .T he s i g n a l s B R A ^ T O S 3 a n d D R A - PO S -F s u p p l y t h e p r o c e s s o rw i t h d r a we r p o s i t i o n i n f o r m a t i o n .T h e s i g n a l s C L K , D AT A, D L E N - 1 , a n d D L E N- 2 c o n t r o l t h et w o L CD d r i v e r s P CE 2 1 1 1 (o n PC B 1 . 7 6 9 . 2 5 0 ) .T he g a i n o f t h e he a d p ho n e s a m p l i f i e r a n d t h eVA R I AB L E O U T P UT i s c o n t r o l l e d by t h e s i g n a l s C L K, D AT A,a n d D L E N -3 (o n P CB 1 . 7 6 9 . 2 8 0 ) .

T h e s l a v e mi c r o p r o c e s s o r (S-]i P, I C4 ) p r o c e s s e s t h es u b c o d e ( s u p p l e m e n t a r y i n f o r m a t i o n o n t h e c o m p a c t d i s k

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r;-:;:,- n^ox B225 SECTION 3/4

3 . 2 . 2 D r a w e r m o t o r c o n t r o lT he dr a w e r m o t o r a m p l i f i e r ( IC l Oa , R 5 2 , 5 3 , 5 6 , 5 7 , a n dR 5 8 , C 1 4 , Q 8 a n d Q9 ) i s c o n t r o l l e d t h r o u g h t h e s h i f tr e g i s t e r IC3 (p i n s 4 a n d 5 ) . If t h e d r a w e r m o v e m e n ti s b l o c k e d d ur i n g t he o p e n i n g o r c l o s i n g o p e r a t i o n ,t h e mo t o r c u r r e n t r i s e s a n d h e n c e t he v o l t a g e a c r o s sR 6 4 . S i g n a l T l o f t h e m a s t e r p r o c e s s o r c o n s e q u e n t l yc h a n g e s ' t o " L" ( c i r c u i t R 40 ,5 4 , 5 5 , 5 9 , 63 , Q 6 , ^ Q 7 , C 1 3 ,a n d I C l O b ) . In r e s p o n s e t h e m a s t e r p r o c e s s o r r e v e r s e st h e d i r e c t i o n o f t h e dr a w e r m o v e m e n t .

3 . 3 S E RV O - 2 P C B 1.769.330

T h e S E RV O 2 P C B 1.769.330 c o n t a i n s t h e c i r c u i t s fo rr a d i a l c o n t r o l a n d t h e IR r e c e i v e r .

3 . 3 . 1 R a d i a l c o n t r o l

A m o v i n g a r m a l l o w s t h e l a s e r p i c k -u p t o f o l l o w t h et r a c k h o r i z o n t a l l y . T h i s a r m b a s i c a l l y f u n c t i o n s l i k ea m o v i n g c o i l i n s t r u m e n t .

T he r a d i a l - c o n t r o l c i r c u i t c a n b e s u b di v i d e d i n t o f o u rb l o c k s :- R a d i a l c o n t r o l c i r c u i t- A G C c i r c u i t- O ff s e t c o n t r o l c i r c u i t- T r a c k d e t e c t i o n c i r c u i t

3.-3.2 R a di a l - c o n t r o l c i r c u i t

T h e v a l u e o f t h e r a d i a l - e r r o r s i g n a l c a n be c o m p u t e da s f o l l o w s ^ R E= kd (II + 1 2 + 1 3 + 1 4 ) - k (II + 1 2 ) .T h e v a l u e o f k i s d e t e r m i n e d by t h e AG C c i r c u i t , a n dd b y t h e o f fs e t c o n t r o l c i r c u i t

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KEI/ OX B 2 2 5 SECTION 3/5

3 . 3 . 3 A u t o m a t i c g a i n c o n t r o l ( AG C) c i r c u i t

The b a n d w i d t h o f t h e r a d i a l - c o n t r o l c i r c u i t i s s t a b i l i z e dby t h i s c i r c u i t . A 65 0 Hz s i n e - wa v e s i g n a l i s g e n e r a t e di n t h e c i r c u i t I Cl O c , IC l l d, C 2 2 , C2 3 # C 2 4 , C 2 5 , R8 5 rR86, R87 ? R 9 0, a n d R 91 . As t he g a i n i n c r e a s e s o rd e c r e a s e s t h e p ha s e r e l a t i o n o f t he s u p p l i e d s i g n a lb e c o m e s a l s o l a r g e r o r s m a l l e r w i t h r e s p e c t t o t her e t u r n i n g s i g n a l * The t wo s i g n a l s a r e c o m p a r e d i n t hep h a s e d e t e c t o r ( ICl l ) a n d a n e w s i g n a l i s de v e l o p e d .

The l a t t e r i s p r o p o r t i o n a l t o t h e p ha g e a n d a ls o t o t heg a i n . T hi s s i g n a l c o n t r o l s t h e f a c t o r k. The g a i n i s la id,ou t fo r a" phas e sh i f t be twee n the s i gn a l s -of -.135 The65 0 Hz . s i n e - wa v e s i g n a l i s t h e r e f o r e fe d i n t o t he c o n t r o ll o o p a t p i n 1 3 o f I C9 d t h r o u g h a 4 5 p h a s e s h i ft e r ( R8 4,C 2 1 ) . T he p h a s e s h i f t i s 9 0 a t t h e i n p u t o f t h e p h a s ed e t e c t o r. T he 6 5 0 Hz s i n e -w a ve s i g n a l i s e l i m i n a t e d fr o mt h e c o n t r o l c i r c u i t t h r o u g h a b a n d p a s s (ICl O d, R8 2 rR 8 3 , C 1 9 , C 2 0) a n d c o n v e r t e d i n I Cl l a t o a s q ua r e - wa v es i g n a l . T hi s s q ua r e - wa v e s i g n a l i s i n p u t t o t he p h a s ec o m p a r a t o r (ICl l c , p i n 8 ) . The p ha s e r e f e r e n c e i ss u p p l i e d by p i n 9 o f I Cl l c .

3 . 3 . 4 O f f s e t c o n t r o l c i r c u i t

T he a s y mm e t r y o f t h e r e f l e c t e d l a s e r b e a m i s c o r r e c t e db y t h i s c i r c u i t t o e n s u r e t h a t t h e l a s e r b e a m i s ke p te x a c t l y o n t h e c e n t e r o f t h e t r a c k . T h e d i f f e r e n c eb e t w e e n m i n i m um a n d m a xi m um r e f l e c t i o n i s t he g r e a t e s t(p r e s e n c e o f p i t = mi n i m um r e f l e c t i o n , be t w e e n p i t s= m a x i m um r e f l e c t i o n ) whe n t h e l a s e r be a m f o l l o w s e x a c t l yt h e c e n t e r o f t he t r a c k .

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mnruiDjiMM HEMOX B225 SECTION 3/7

3 . 5 . 1 D i g i t a l s i g n a l p r o c e s s i n gT he H F s i g n a l i s c o n v e r t e d i n I C1 3 (SAA 70 1 0} i n t od i qi t a l s i q n a l s a n d s p l i t i n t o a ud i o a n d i n fo r m a t i o nd a t a ( s u bc o d e , fo r t h e s l a v e p r o c e s s o r ) . The CLOCKs i g n a l i s a l s o r e g e n e r a t e d i n J C 1 3 . T h e a u d i o d a t aa r e b r o u g ht i n t o t he c o r r e c t t i m e s l o t p a t t e r n . Co r r u p t e da u di o d a t a a r e n o t r e c o g n i z e d i n 1 C1 2 a n d c o r r e c t e di f n e c e s s a r y . Sho ul d t he e r r o r s be i n c o r r i g i bl e , t hem i s s i n g s a mp l e v a l ue s a r e r e p l a c e d in. I C10 SAA 7000)t h r o u g h i n t e r p o l a t i o n . S ho ul d t hi s a l s o b e i n f e a s i b l e ,

t h e H F s i g n a l i s s l o wl y mu t e d ( s o ft m u t i n g ) . T h e s p e e do f t h e CD m o t o r i s c o n t r o l l e d b y t he signal MCES IC1,p i n 4 ) .

3 . 5 . 2 D i g i t a l s i n e - wa ve g e n e r a t o r

The PROM IC4) c o n t a i n s a v a l ue t a b l e fo r t h e s i n e -wa v es i g n a l w hi c h r e p r e s e n t s t he ma x i m um p o s s i b l e l e ve lo f a C D .

T he c i r c u i t c o n s i s t s o f IC5 t h r o u g h I C9 wi t h I C5 a n dIC6 s u p p l y i n g t h e a ddr e s s e s fo r t h e P RO M. Pa r a l l e l / s e r i a l

d a t a c o n v e r s i o n i s p e r f o r m e d i n IC 3 . The c h a n g e - o ve rb e t w e e n a u d i o d a t a fr o m t he C D a n d t h e 1 kHz s i n e -w a ves i g n a l i s c o n t r o l l e d by I C1 .

3 5 3 H FL a n d D O de t e c t o r

The HF s i g n a l i s fe d i n t o t he i n v e r t i n g di f fe r e n t i a la m p l i f i e r Q l a n d Q2 t hr o u g h C6 a n d R 2 . Th e o u t p u t s i g n a l sa r e D C -d e c o u p l e d v i a C8 a n d C9 r e s p e c t i v e l y a n d t i e dt o D C g r o u n d vi a D 2 a n d D 3 . D 4 a n d D 5 o r D 6 an d D 7r e s p e c t i v e l y c o n s t i t ut e a ful l - wa v e r e c t i fi e r e a c ht h r o u g h wh i c h t he c a p a c i t o r s C1 0 o r Cl l a r e c h a r g e d .

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r ' r : ; T * 5 R ^ Q X B225 SECTION 3/8*

The p r e e m p ha s i s i s c o r r e c t e d w i t h t he c i r c u i t i l l us t r a t e ci n F i g . 3 . 1 3 . T h e s u b c o d e o n t h e C D s p e c i f i e s w h e t h e rt h e s e l e c t i o n wa s r e c o r d e d wi t h or w i t ho u t p r e e m p ha s i s .The c ha r a c t e r i s t i c o f t he c o r r e s p o n d i n g fi l t e r c a nb e a d j u s t e d w i t h t h e P R E E M s i g n a l .

3 . 6. 2 Le v e l a d j us t m e n t a n d h e a dp h o n e s a m p l i f i e r

T he v o l u m e i s c o n t r o l l e d b y a D UAL D /A c o n ve r t e r

( A D 7 5 2 8 ) . It s e r v e s a s a n a t t e n u a t o r be f o r e t h ec o r r e s p o n d i n g i n p ut (IC1 0 3 a , p i n 2 = l e f t -ha n d c h a n n e l/ IC 203b f p i n 6 = r i g h t -h a n d c h a n n e l ) . The n e g a t i v e -fe e db a c k r e s i s t a n c e s o f bo t h o p a mp s r e m a i n u n c h a n g e dw hi c h me a n s t h a t t h e l e ve l c a n o n l y be a t t e n u a t e d w i t ht h i s c i r c u i t . T he dua l D /A c o n ve r t e r i s c o n t r o l l e d by aC MO S s hi f t r e g i s t e r t h r o u g h t h e s i g n a l s D L E N -3 , D ATA, a n dC LK . The c i r c u i t i l l us t r a t e d i n Fi g . 3 . 1 4 c o n s t i t u t e s t heo u t p u t a m p l i fi e r fo r t h e h e a dp h o n e s s o c k e t a n d a l s ot h e VAR IA BL E O UT PU T* The s i g n a l i s a l s o a t t e n u a t e d fo rt h i s p u r p o s e t h r o u g h a vo l t a g e di vi de r s o t ha t t h e s i g n a li s t h e s a m e (2 V R M S) a t b o t h o u t p u t s (FIXED a n dVA RIA BLE) . T he s i g n a l i s t a ke n t h r o ug h r e l a y Kl i n o r d e rt o p r e v e n t p o w e r -o n s wi t c h i n g c l i c k s . Whe n p o we r i sa p p l i e d. , t h e r e l a y i s s e l e c t e d b y t h eK IL L s i g n a l (whi c h r i s e s t o + 5 V a f t e r a p p r o x i m a t e l y1 t o 2 s e c o n d s ). A s a r e s u l t , t h e o ut p u t s a r e o n l yt h r o u g h-c o n n e c t e d whe n t he s up p l y vo l t a g e s a r e s t a b l e .

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REI/OX B225 S E C T I O N 4 / 1

4. TEST POINTS, ADJ USTMENTS ON B2 2 5

4 i Te s t p o i n t s o n B2 2 5

4 . 1 . 1 Te s t p o i n t s o n S E RV O 1 P CB 1 . 7 69 . 3 1 0

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'lDj[j R ^ O X B225 SE C T I O N 4 / 2

I f n o CO i s m o u n t e d w h e n P LAY i s s e l e c t e d * t h e s i g n a l s o n T P 2 6a n J 2 7 b e c o m e ^ l? V i n f o u r i n t e r v a l s o f a p p r o x i m a t e l y o n e s e c o n de a c h

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w^rumi R ^ O X B225 SECTION 4/3

4 . 1 . 2 T e s t p o i n t s o n SE RV O 2 P C B 1 . 7 69 . 3 3 0

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h F t E M O X B225 S E C T I O N 4/4

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R ^ O X 6 5 SECTION 4/5

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T \:WM REl/OX B 2 2 5 SE C T I O N 4 / 6

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WU F I E M Q X B 5 SECTION 4/7

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L ^=.1^ FIEMQK B 2 2 5 SECTION 4/8

4 . 1 . 5 T e s t p o i n t s o n D A C P CB 1,769.280

T he i n t e r n a l c a l i b r a t i o n m us t be s w i t c h e d o n fo r t h ef o l l o w i n g m e a s u r e m e n t s ;

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c ^= KEI /O X B225 SECTION 4/9

4 m Adjustments on CD player B225

Note:

C l e a n l i n e s s in t h e wo r k a r e a is of o u t mo s t i mp o r t a n c ea n d e n s u r e s that no c o n t a m i n a n t s or me t a l p a r t i c l e sc a n e n t e r i n t o t h e CD me c h a n i s m .

I f any work on p r i n t e d c i r c u i t bo a r ds is n e c e s s a r y,i t is e s s e n t i a l to o b s e r v e t h e E SE r e c o m me n d a t i o n s( r e f e r to l a s t p a g e of c o n t e n t s ) .

B e f o r e p u t t i n g t h e CD p l a ye r i n t o o p e r a t i o n e n s u r et h a t t he t r a n s p o r t s c r e w s ha ve b e e n u n fa s t e n e d .

The CD p l a y e r me c h a n i s m is e q ui p p e d wi t h s e l f-l u br i c a t i n gb e a r i n g s w hi c h s ho ul d n o t be l u br i c a t e d.

I f t h e d r a w e r m u s t be o p e n a n d a di s c mo u n t e d in o r d e rt o p e r f o r m c e r t a i n m e a s u r e me n t s or a d ju s t m e n t s , the r e a r l i g h t b a r r i e r m u s t be i n t e r r u p t e d (t he d e t e c t o rr e s p o n d s as if t he d r a we r we r e c l o s e d ) a n d t he c o m p a c td i s c m u s t be s e c u r e d wi t h a r e m o v e d a d he s i ve m a g n e t .

T he o p t i c a l s ys t e m of t he l a s e r c a n be c l e a n e d wi t ha n a i r b r us h .

Coil Ll on the decoder PCB 1.769.300 is automaticall yaligned by IC13 SAA7010) and consequently requiresno adjustment*

4 2 1 Aids

- DC v o l t me t e r

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REMGX B225 SECTION 4/10

4 . 2 . 5 A d j u s t i n g t h e f o c u s g a i n

-- Swi t ch CD p la yer o ff , remo ve SERVO 1 PCB 1 .76 9.310a n d r e i n s e r t i t vi a t h e s e r v i c e P CB .

- C o n n e c t AF g e n e r a t o r t o t he X i n p u t o f a n o s c i l l o s c o p ea n d v i a a n R-C-R e l e m e n t ( a c c o r d i n g t o F i g . 4. 1 2 )to p i n 6 o f IC2 (on 1 . 7 6 9 . 3 1 0 ) , (f=600 Hz +5 Hz,U =2 5 0 t o 3 00 mV R M S ) .

- Wi t h t r i m me r p o t e n t i o m e t e r R 5 8 (o n p l a y e r m e c h a n i s mP C B 1 . 7 69 . 1 0 0 . 3 5 ) , a l i g n fo r m i n i m u m a m p l i t u d e Ao f t h e L i s s a j o u s f i g u r e .

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^ - y i L r ^ J u R ^ O X B 2 2 5 SECTI ON 4/11

T he a n g l e a l i g n m e n t m us t be c o r r e c t e d i f t h e de v i a t i o ni s t o o l a r g e :

- U n f a s t e n s c r e w [ A] u n t i l t he s u p p o r t p l a t e B] c a nb e s h i f t e d .

- The s u p p o r t p l a t e c a n n o w be s h i f t e d a c c o r d i n g t oF i g * 4 . 5 . Re t i g h t e n t he s c r e w [ A ] wh e n t h e p o s i t i o ni s c o r r e c t .

- The a n g l e a l i g n m e n t m us t be r e c h e c k e d a ft e r t h ef o r e g o i n g a d j us t m e n t s h a ve b e e n m a d e .

4 . 2 . 7 A dj us t i n g t h e D C c o m p o n e n t o f t he fo c u s s i g n a l

- C o n n e c t D C v o l t m e t e r t o R l ( S E RV O 1 P CB 1 . 76 9 . 3 1 0 ).

T he f o l l o w i n g a d j us t m e n t i s o n l y n e c e s s a r y i f t h e D Cd e vi a t i o n e x c e e d s +JL4 0 m V. Re p l a c e t h e m o t o r i f a l i g n m e n ti s n o t p o s s i b l e .

- Ad ju s t t h e a x i a l s e t s c r e w o f t h e d i s c m o t o r i n s u c ha w a y t h a t 0 V +_50 m V i s m e a s u r e d .

- If t h e mo t o r i s r e p l a c e d , p e r f o r m t he a d ju s t m e n t s

a c c o r d i n g t o 4. 2 . 6 a n d 4 . 2 * 7 *

4. 3 M e a s u r i n g t h e a u di o d a t a

4 . 3 . 1 A i d s

-_ R e f e r e n c e C D , p a r t N o . 4 62 4 0- A ut o m a t i c d i s t o r t i o n m e t e r ( e . g . Te k t r o n i x AA 5 0 1 ;

t h e R E S P O NS E b ut t o n m u s t b e i n t h e R MS p o s i t i o n f o ra l l m e a s u r e m e n t s )

- M e a s u r i n g f i l t e r (fo r d i s t o r t i o n m e a s u r e m e n t )~ F r e q u e n c y c o u n t e r

?rr-S- :JL\Fi FI /OX B225 SECTION 4/12 *

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?rr S JL\Fi FI /OX B225 SECTION 4/12

4 . 3 . 5 C r o s s t a l k

- Ad j u s t f o r m a x i m u m l e v e l w i t h V OL U M E + k e y ,- R e f e r e n c e = C A L T O N E 1 0 0 0 H z )- M e a s u r e b o t h o u t p u t s a c r o s s a 3 0 k Hz l o w -p a s s :

P l a y t r a c k 8 fo r me a s u r i n g c r o s s t a l k R -> LP l a y t r a c k 4 fo r me a s u r i n g c r o s s t a l k L -> R

- Th e c r o s s t a l k a t t e n u a t i o n s h o u l d be a t l e a s t 90 d B .

4 . 3 . 6 S i g n a l - t o - n o i s e r a t i o , l i n e a r

- M a x i m u m v o l u m e , r e f e r e n c e = C A L T O N E 1 0 0 0 H z .- P l a y t r a c k 1 8 a n d m e a s u r e t h e o u t p u t s F I XE D a n d

VA R I A BL E vi a a 3 0 k Hz l o w - p a s s .- T h e m e a s u r e d va l u e s h o u l d b e hi g h e r t h a n -96 d B ,

4 . 3 . 7 S i g n a l - t o - n o i s e r a t i o , w e i g h t e d

- M a x i m u m v o l u m e , r e f e r e n c e = C A L T O N E 1 0 0 0 H z .- P l a y t r a c k 1 8 a n d m e a s u r e t h e o u t p u t s F I XE D a n d

VA R I A BL E v i a a n A f i l t e r .- Th e m e a s u r e d v a l u e s h o u l d be h i g h e r t h a n 1 00 d B ,

4 . 3 . 8 P ha s e l i n e a r i t y

- C o n n e c t o s c i l l o s c o p e t o o n e o f t h e o u t p u t s .- P l a y t r a c k 2 0 a n d v i s u a l l y a s s e s s t h e s q u a r e - w a v es i g n a l s a t 1 0 0 H z , 4 00 H z , 1 00 2 H z , a n d 5 5 1 2 H z .T h e c u r v e s h o u l d b e s h a p e d s y m me t r i c a l l y (s e eF i g . 4 . 1 7 ) . , .

4 . 4 L i s t e n i n g t e s t w i t h r e f e r e n c e C D (p a r t N o . 4 6 2 4 1 )

T he r e f e r e n c e C D s i mu l a t e s t h e f o l l o w i n g e r r o r s fo rc h e c k i n g t h e e r r o r c o r r e c t i o n s y s t e m :- I n f o r m a t i o n g a p s w i t h a l e n g t h o f 4 00 t o 9 00 p m ( t r a c k s

5 t h h 9)

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