Technics STCH 770 Service Manual

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H

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ORDER NO AD960305108

Service Manual

Tuner/Sound Processor

or]-

PFtO' LOGIC
*SB-CHTIO

* SB-PC10

1 SL-CHTIO

* S B-PS1 0

7k

RS-CH77D

ST-CH770 '

SE-CH770

Y SB-CH770

Because of unique interconnecting cables, when a component
requires service, send or bring in the entire system

Specifi cations
I Pre-amplifier section
lnput sensitivity/impedance
PHONO
EXTERNAL, VCR, VDP
Output level
EXTERNALNCFI FIEC OUT
Frequency response
PHONO
EXTERNAL, vcn, VDP
SIN
PHONO
EXTERNAL, VCFI, VDP
I EQ/SFP section
Center irequency
EG SPACE mode
3 modes
V. BASS mode
Center frequency
V. BASS 1
V. BASS 2
I DOLBY PRO LOGIC section
PRO LOGIC mode
CENTER mode
DELAY TIME
I FM tuner section
Frequency range

2.5 mV/47 kg
250 mV/15 kg

150 mV/1,5 kg

30 HZ- 15 HZ/+1.5 to ~20 dB
. 20 HZ -40 kHz

DIN 73 dB (77 dB, IHF)
DIN 80 dB.(82 dB, IHF)

120 kHz. 1 kHZ. 7 kHz
HALL. CLEAR, HEAW
70 Hz

+13 dB

+6 (13

SURROUND. 3 STEREO

NORMAL, WIDE, PHANTOM
20 ms (Fixed)

87,50 - 108.0 MHZ (0.05 MHz steps)

, Tuner
Colour
(K) 2 Black
Areas
Suffix for Area Colour
Model No.
(E) Europe
Remote Control - (EB) Britain
Transmitter ' (K)
(EG) Germany and ltaly
Asia, Latin America,
(GO) Middle East, Africa and
Oceania
System: SC-CH770
Stereo separation ,
1kHz 7 35 dB

Antenna terminal(s)
I AM tuner section
Frequency range
[For (E) and (EB) areas) MW

75 Q (unbalanced)

522-- 1611 kHZ (9 kHz steps)
530 -1620 kHz (10 kHz steps)
LW 144- 288 kHz (9 kHz steps)

[For (EG) and (60) areas] AM 522- 1611 kHz (9 kHz steps)
530 -1520 kHz (10 kHz steps)

Sensitivity (SIN 20 dB)
[For (E) and (EB) areas] MW 500 pV/m
LW . 50 V
[For (EG) and (66) areas] AM 500 uV/m

l Timer section

Clock Quart-lock type
Function 24-hour programmable;
Play limer (1 time). REC timer (1 time),
Sleep (120 min, 30 min intervals)
Setting 1 minute-23 hours 50 minutes
(1 min intervals)

I General
Dimensions (W x H x D) 270 x 89 x 282 mm
Weight 17 kg

Sensitivity 1.8 11V (lHF usable) .
S/N 26 GB 1.5 [JV Note: Specifications are subject to change without notice,
S/N Weight and dimensions are approximate.
MONO 70 dB (75 dB. IHF)
Tuner/sound Compact disc . Front Center Surround
System processor changer Amplifier Cassette deck speakers speaker speakers
SC-CH770 ST-CH770 SL-CH77O SE-CH770 HS-CH77O * SB-CH770 *SB-PC1O * SB-PSi o
* For (E),(EB) and (EG) areas: Made in PAES
For (GO) area : Made in NABEL
AWARNING

This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not
contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.

Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or
repair the product or products dealt with in this service information by anyone else could result in serious injury or death.

Technics®

© 1996 Matsushita Electric industrial 00., Ltd.
All rights reserved. Unauthorized copying
and distribution is a violation of law.

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ST-CH770

I Contents

Location of Controls 2 Schematic Diagram ..............

Setting the Time ....... . 2. 3 Printed Circuit Board Diagram. 30 ~ 33

Enjoying RDS Broadcast [For (E) and (EG) areas]. . 8 4 Wiring Connection Diagram. 34

About the Self-Diagnostic Mode 5 Block Diagram... 5 ~ 40

Operation Check and Function of IO Termina s .. 41, 42
Main Component Replacement Procedures. Replacement Parts List 43 ~ 60

To Supply Power Source ..............................
Measurements and Adjustments [For (E) and (EG) areas]
NOTE.

Refer to the service manual for Model No. SE-CH770 (ORDER No. AD960305508) for information on Accessories,
Installation, "Connections and Packaging.

I Location of Controls.

Cabinet Part5 Location .

(D Source input select button (SELECTOR)
® Remote control signal sensor (SENSOR)

® Karaoke mode select button (KARAOKE)
f??? r @m.
II I, II

® Tuning/timer select button (TUNING/TIMER)
© Set button (SET)

® Record timer button (Q) REC)

Play timer button (9) PLAY)

J

® PTY select button (PTY)...for (E) and (EG) areas
('6 6 65 ($656 @656 Egg: ® PTY search button (PTY SEARCH)...for (E) and (EG) areas
@ FM/FM mode select button (FM, -AUTO/MONO)
T 63) Tuner indicator (TUNER)
[Fartcciarea] (For (E) andtiei areas] ® LW/MW select button...for (E) and (EB) areas

AM button...for (EG) and (GC) areas
® Tuning mode select button (TUNING MODE)
® Clock/timer button (CLOCK/TIMER)
® Echo button (ECHO)...for (GC) area

I Setting the Time

This is a 24-hours display clock.
These instructions explain how to set the timer for 16:25 (4:25 pm.) on Wednesday.

1
POWER

STANDEYEg 1) I

CLOCK]
T|MEH SET

g 3
: ® TUNINGITIMER ®

[p ,9 i ® Display mode select button (DlSP MODE)...for (E) and (EG) areas

H

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I_.-_> : FM signal line IL, : AM signal line A : REC OUT signal line W : MIC signal line ST H770 ,

=5 : Center speaker drive signal line 55557 : Surround speaker drive signal-line ~

E DOLBY PRO LOGIC CIRCUIT (Refloardzon page '32)

TOEMAIN
CIRCUIT
(CN801)
on page 22

TOE MAIN
CIRCUIT
(CN701)
on page 22

SIGJ. our 9 7 . 10702
sIGrR our ct McuoszaFRz
INPUT SELECTOR

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UN4211AITA FW70I
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VCR IN T a
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TV MONITOR OUT , R719 sea 75 a

Sex 75 AMP DRIVER
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31* AMP DRIVER
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VIDEO AMP

E VIDEO CIRCUIT (P.C.VBoard:on page 31)
._ 27 _

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ST-CH770

For (EB) area
RefJb. Part N0 Part Name 0 Description Remarks Ref. N0 Part No. Part Name 0 Description Remarls
0000 004 004115 TRANSISTOR
INTEGRATED 010011110) 0005, 000 2S01400RTA TRANSIst
007,000 0000270 TRANSISTOR
10101 LAIBSZMH-TEL 10,011 IF AIR. 0000 ONAII5 TRANSISTOR
10102 LC7218M-TE-I. 10.001 ERROSTNIIIESITER 0011, 012 25021071100 TRANSISTOR A
10201 ANBESSSFEZ 10.0110NO E0 AMP. 0001 1042140 TRANSISTOR
10202 0107310012 10.111110 SELECIOD 0002-004 2scsaTIA-0 TRANSIst
10200 1152100120 1001100011 AMP. 0005 0N4IIETA TRANSISTOR
10001 M52422FPE1 10, DIGITAL SOUND OONT. 0000 2000011A-0 TRANSISTOR
10002 M62425FPE1 IO,ELROTRONIO MORE I 0007 0N4IIR TRANSISTOR
10001 10450050101 Tc,NIc AMP. 0000 2S02144S TRANSIst
10581 MOMOBBDFEL IC, SWITCHING
10701 0112270012 Ic,VIDEO A110. DIODE (S)
10702 110140520st 10.111001 SELECIOR
10001 027051 10, 001011 000 00010 CONTROL 0101 1040511110 DIODE A
10002 Iv1010N1 1000101 000 10010 DRIVE 0102 10100 01000
10000 0024250101 Ic,ELEcTRONIO VOLUME 0251 102010 DIODE
10004 0521001701 IO,DDTEER A110. 0001 104051-1. DIODE A
10001 00190111110000 10.810030 CONTROL/FL DRIVE 0002 NAIss DIODE
- D504 MA4ODZMTA DIODE A
TRANSISTOR 0001-004 RL1N4003NOZ DIODE A
D605 M0165 DIODE
0101, 102 23027071 TRANSISTOR 0000.007 107100 DIODE
0100 104 250270500 TRANSISTOR 0000 104070110 DIODE A
0100 0N4111 TRANSISTOR 0010 NA40021TA DIODE A.
0107,1011 stSSIIARSTA TRANSIst 0011, 012 011N4000N02 DIODE A
0191-100 stISIIARSTA TRANSIst 0010. 014 101000 DIODE A
0251. 252 2SD2144S TRANSISTOR 0015 MA4D§1MTA DIODE A
0304 2SD2144S TRANSISTOR 0010 104002-11 DIODE A
0000 000 20001100 TRANSISTOR D017 0040000 DIODE A
0007, 000 20021440 TRANSIst 0010021 001050 , DIODE A
0300. 010 0N4115 TRANSISTOR 0022 MA4OSQMIA DIODE A
001?, 010 2301309117]? TRANSISTOR 0001 NA7OOTA DIODE
0015, 010 20301100 TRANSISTOR 0002 10100 DIODE
0017 004115 . TRANSIst 0051,1152 10100 DIODE
0500 23000400100 TRANSIst A 0050 NAIIOTA DIODE
0501 0N4211 TRANSISTOR 0701, 702 104050.00 DIODE A
0502 0N4111 TRANSISTOR 0001-000 0000 DIODE
0500 1104211 TRANSISTOR 0000 1104100110 DIODE A
0001 ZSD2137PQTA TRANSISTOR A D010 10105 DIODE
0002 2501417000 TRANSIst A 0001,1102 04105 DIODE
0000 5021071200 TRANSISTOR A 0000 SPRSDEMDTT I. E. 0.
(1604 ED214418 TRANSISTOR [1910-512 LSSZEITA DIODE
0005 2S021071>0TA TRANSISTOR A 0003,4104 10105 DIODE
0000 2S0021A-R TRANSISTOR A 0000, 007 10100 DIODE
0007 0N4213AITA TRANSISTOR 0040 10100 DIODE
0000 0N4111 TRANSIst
0014 2SDI417R0TA TRANSISTOR A OONRONENT OORDINATION(S)
0701 ZSBEZIA-R TRANSIst A '
0702 2505020100 TRANSIst A 2102 01122000110 OONRONENT OONDINATION
0700 0N4211 TRANSISTOR 2120 01111010 1111 ERDIT 0110
0801, 002 25014501110 TRANSISTOR 2101 RIAOZOOSII-T OOIRONENT OOIIDINATION

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