Technics SLCH 770 Service Manual

Page 1

ORDER NO.

AD9603053C8

Service Manual

Compact Disc Player

SL-CH77O

COMPACT

disc

DIGITAL AUDIO

DlGlT/IL

*2 SB-CH770

iZSB-PSW

RS-CH770

CD Changer

multlAstago noise shaping

*2se-Pc1o

*3 SB-CH77CI

ST-CH77I - .

SE-CH770

*1

*2 SB-PS10

Remote Control
Transmitter

requires service, send or bring in the entire system.

[ Because of unique interconnecting cables, when a component ]

RAE01502 MECHANISM SERIES
Specifications

I Audio

DA converter
I Pickup
Wavelength
I General

Dimensions (W er x D)

1 bit 2 DAC MASH

780 nm

27o><89><330 mm

N otes:

Colour
(K) : Black
Areas

Suffix for Area Colour
Model No.

Europe. Asia, Latin

(E) America. Middle East. (K)
Africa and Oceania

System: SC-CH770

Specifications are subject to change without notice.
Weight and dimensions are approximate,

*1 MASH is a trademark of NTT.

Weight 2.4 kg
Tuner/sound Compact disc . . Front Center Surround
System processor changer Amplifier Cassette deCk Speakers speaker speake rs
SC-CH770 ST-CH77O SL-CHTIO SE-CH77O RS-CH77O *2 SB~CH77O *2 SB-PCi O *2 SB»PSi 0
*3 For Europe area: ................. Made in PAES
Except for Europe 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 Malsushita Electric Industrial Co., Ltd.
All rights reserved. Unauthorized copying.
and distribution is a violation of law.

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sealant. |

I Contents Page - V Page
Handling Precautions for Traverse Deck ........................................... 2 Schematic Diagram ..... 21 ~25
Precaution of Laser Diode . 2, 3 Printed Circuit Board Diagram . 26~28 ,
Location of Controls ....... 3 Wiring Connection Diagram 28
How to Set the "Transport Mode 3 Function of 1C Terminals. . 29~31
Loading and Checking Compact Discs 4 Troubleshooting Guide 32, 33
Listening to Compact Discs ......... 5 Block Diagram ....... 34, 35

Operation Check and - Replacement Parts List . 36~39

Main Component Replacement Procedures . 6~17 Cabinet Parts Location . 40
Error Code Display and Serve Adjustment Function 18, 19 Loading Unit Parts Location 41
To Supply Power Source .....................................

NOTE: >
Refer to the service manual for Model No. SE-CH770 (ORDER No. A0960305568) for information on Accessories,
Stacking the Components, Connections and Packaging: ,

CAUTION:

THIS PRODUCT UTILIZES A LASER. .

USE OF CONTROLS OR ADJUSTMENTS OR PERFORMANCE OF PROCEDURES OTHER THAN THOSE
SPECIFIED HEREIN MAY RESULT IN HAZARDOUS RADIATION EXPOSURE.

I Handling Precautions for Traverse Deck

The laser diode in the traverse deck (optical pickup) may break down due to potential difference caused by static electricity of clothes or human body.
So be careful of electrostatic breakdown during repair of the traverse deck (optical pickup).

0 Handling of traverse deck (optical pickup)

1. Do not subject the traverse deck (optical pickup) to static electricity as
it is extremely sensitive to electrical shock.

2. To protect the laser diode against electrostatic breakdown. short the
flexible board (FFC board) with a clip or similar object.

3. Take care not to apply excessive stress to the flexible board (FFC Short olnt
board).

4. Do not turn the variable resistor (laser power adjustment). [t has al-
ready been adjusted.

C Grounding for electrostatic breakdown prevention
1. Human body grounding -
Use the anti-static wrist strap to discharge the static electricity from
your body.
2. Work table grounding .
Put a conducive material (sheet) or steel sheet on the area where the
traverse deck (optical pickup) is placed, and ground the sheet.

Caution:

The static electricity of your clothes will not be grounded through the wrist
strap. So, take care not to let your clothes touch the traverse deck (optical
pickup),

FFC board
(Handle It carefully)

Variable resistor

No.©(GND) pin No.@(LD) pin (Do nomm)

Wrist strap
(Anti-staticbracelet) /

conduct electricity

1M9

Caution when Replacing the Traverse Deck:
The traverse deck has a short point shorted with solder to protect the laser diode against electrostatic breakdown. Be sure to remove the solder from
the short point before making connections.

I Precaution of Laser Diode,

CAUTION: This product utilizes a laser diodewith the unit turned on, invisible laser radiation is emitted from the pick up lens.
Wave length: 780 nm
Maximum output radiation power from pick up': 100 uWNDE

Laser radiation from the pick up unit is safety level) but be sure the followings:

1. Do not disassemble the pick up unitx since radiation from exposed laser diode is dangerous.
2. Do not adjust the vaiiable resistor on the pick up unit It was already adjusted.

3. Do not look at the focus lens using optical instruments,

4. Recommend not to took at pick up lens for a long time.

ACHTUNG: Dieses produkt enthalt eine laserdiode. lm eingeschalteten zustand wird unsichtbare laserstrahlung von der lasereinheit
adgestrahit.
Wellenlange: 780 nm
Maximale strahlungsleistung der laserinhelt: 100/1WNDE

Die strahlung an der lasereinheit ist ungefahrllch, wenn folgende punkte beachtet werden:

1. Die lasereinheit nicht zerlegen. da die strahlung an der ireigelegten laserdiode gefahriich ist,
2i Den werksseitig justierten einstellregler der lasereinreit nicht verstellen.

3. Nicht mit optischen instrumenten in die fokussierlinse blicken.

4. Nicht fiber lingere zeit in die fokussierlinse blicken.

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Page 18

SL-QH77O

I Error Code Display and Servo Adjustment Function

This unit has an error code display function, so that if the unit operates incorrectly, the fault is displayed using an error
code on the FL display of the tuner (ST-CH770). It also has a servo adjustment function for displaying the status of.
servo system functions (Focus, Tracking, CLV Servo) on the tuners FL display.

The system control IC and FL display are part of the tuner so make sure the system hasbeen connected properly
before using three functions. (This unit can be operated independently, although the error code display and servo
adjustment functions cannot be used.)

Use these two functions for guidance during fault diagnosis and repair.

Note; ' _

Check beforehand for scratching or soiling of the test disc (SZZP1054C), and soiling or other problems with
the pickup lens.

0 Error code display procedure
Automatic adjustment results ' Checking the mechanism switches

I Turn the power ON. I

l . Press the F. SKIP button.

| ' Load the test disc (SZZP1054C). j

A mechanism OK/NG error code is displayed. (See Table 1.)
Hold down the REPEAT button for at least 2 seconds, and then This error code can be used diagnose whether or not the mecha-
press the STOP button for at least 2 seconds while continuing to . nism is 0K. ltthere are multiple errors these can be displayed
hold down the REPEAT button. successively by pressing the F. SKIP button.
A servo section error code is displayed. (See Table 2.) Remove the disc and turn the power OFF. (The error code display
Use this error code display as a guideline for finding the malfunction mode is canceled.)
point in the servo circuitry. if the error code E-OO" is displayed, the
unit is "OK (No problem)

O Servo adjustment procedure

I Turn the power ON. I

| Load the test disc (SZZP1054C). l

Hold down the REPEAT button for at least 2 seconds, and then
press the PAUSE button for at least 2 seconds while continuing to
hold down the REPEAT button.

Press theb (PLAY) button, and play for 10 seconds.

(Example)

Servo adjustment results are displayed. :III II:II :III

. : III 2} Normal
III I III IIII

Focus Tracking CLV servo
IIII II:II :III

I III I , I I I" "H." level

I I . "L level "H level
III I III IIII III "L" level
. Focus system normal defective
Tracking system _ normal ' defective
Remove the disc and turn the power OFF. CLV servo system defective normaj

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SL-CH770

ISchematic Diagram
Page

SERVO CIRCUIT 22,23
. E SWITCH CIRCUIT 24

SWITCH ($2, $3) CIRCUIT. 24
E] LED CIRCUIT 24
E LOADING MOTOR CIRCUIT........................... 24
OPERATION CIRCUIT .. ....... ...... .......24

MAIN CIRCUIT ........ . 24,25

C This schematic diagram may be modified at any timewith the development of new technology.

. Notes:

0 S1 : Stacker position detect switch
0 $2 : Play position detect switch
0 53 : Up position detect switch
0 $4 : Tray open detect switch
0 55 : Disc number detect switch - .
0 $601 : Disc select switch (DISC 5) ,

. 0 $602 : Disc select switch (DISC 4)

0 $603 : Disc select switch (DISC 3)

0 5604 : isc select switch (DISC 2)

O 5605 : isc select switch (DISC 1)

I 5606 1 Disc check switch (DISC CHECK)
O 5607 : Repeat switch (REPEAT)

0 $608 : Al edit switch (Al EDIT)

I 8609 : Random play switch (RANDOM)
0 $610 : Fi. Skip/Search switch (Md/44 )
O 5611 : Stop switch (CI)

0 $512 : Play switch (l>)
. I 3613 : F. Skip/Search switch,( »/»I)
0 $614 : Pause switCh (II)

O 8615 : Disc tray open/close switch (A OPEN/CLOSE)
0 S701 : Rest switch

. Indicated voltage values are the standard values for the unit measured by the DC electronic circuit tester (high-impedance) with the chassis
taken as standard. Therefore, there may exist some errors In the voltage values, depending on the internal impedance of the DC circuit tester.

No mark: GD STOP
( ) :CD PLAY[1kHz,L+R.0dB]

0 Important safety notice:
. Components identified by A mark have special characteristics important for safety
Furthermore special parts which have purposes of fire-retardant (resistors). high-quality sound (capacitors), low-noise (resistors), etc. are
used. When replacing any of components, be sure to use only manufacturer's specified parts shown in the parts list.

I Caution!
IC and LSI are sensitive to static electricity
. Secondary trouble can be prevented by taking care during repair.
Cover the parts boxes made of plastics with aluminum foil.
Ground the soldering iron
Put a conductive mat on the work table.
~ Do not touch the legs of [C or LSI with the fingers directly.

I Voltage and signal line
:Jfi : Positive voltage line

Q : CD signal Line

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