Technics SLEH 750 Service Manual

Page 1

ORDER NO. AD990306608

Service Manual

Compact Disc Player

w 000...an SL-EH750
disc

DIGITAL Auolo (S) ........ Silver Type
Area
H *1 (E) ........ Europe.
mismanagement. *2 SB-PS75 *2 SB-PS75

Remote Control

Transmitter System SC-EHYSD
' Sound Processor SH-EH750
*2 SB_pc75 . t , . Tuner/Amplifier SA-EH750
' ' CD Changer SL-EH750
" ' . Cassette Deck RS-EH750
*2sa-EH750 RS-EH750 SA-EH750 *2sa-EH750 Front Speakers SB-EH750
Center Speaker2 SB-PC75
Surround Speakers2 SB-PS75

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

Traverse Deck : FIAE01522 MECHANISM SERIES

Specifications

Audio Section General

No. oi channels: 2 (left and right, stereo) Dimensions (W>< D): 293x89><288 mm
Frequency response: 20 to 20,000 Hz (+0.5 dB to -2 dB) Weight: 2.2 kg
Output voltage: 0.78 V (at 0 dB)

Dynamic range: 85 dB Notes: Specifications are subject to change without notice.
SIN: 95 dB Weight and dimensions are approximate.

Total harmonic distortion: 0.02 % (1 kHz, 0 dB) Total harmonic distortion is measured by the digital
Wow and flutter: Below measurable limit spectrum analyzer.

Digital filter: 8 is *1: MASH is a trademark of NTT.

DA converter: 1 bit DAC MASH *2: Made in Singapore.

Output impedance: 1 k0

Load impedance: More than 10 kt)

Pickup Section
Wavelength: 780 nm

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.

© 1999 Matsushita Electric Industrial Co.,Lid.

. ® All rights reserved. Unauthorized copying
ec nlcs and distribution is a violation of law.

Page 2

SL-EH750

I Contents

Handling Precautions for Traverse Deck
Precaution of Laser Diode .............
Location of Controls
Operation Checks and
Component Replacement Procedures ...............
Error Code Display and Servo Adjustment Function .

Wiring Connection Diagram

Type Illustration oi ICs, Transistors and Diode
Troubleshooting Guide
Block Diagram ............
Terminal Function of IC
Replacement Parts List .
Cabinet Parts Location ..

Schematic Diagram ...............
Printed Circuit Board Diagram

Loading Unit Parts Location

NOTE:
Refer to the service manual for Model No. SA-EH750 (ORDER No. A0990306302) for information on Accessories",
"Connections", "installation", "Operations 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.

l 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 board).

4. Do not turn the variable resistor (laser power adjustment). It has already been
adjusted.

FFC board
(Handle it carefully)

Lens (Do not touch)

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

Variable resistor
(Do not turn)
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).

Wrist strap
(Anti-static bracelet) /

n plate or some metals to
conduct electricity

1M1)

l Precaution of Laser Diode

CAUTION: This product utilizes a laser diode with 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 pW/VDE
Laser radiation from the pick up unit is safety level, but be sure the followings:

1. Do not disassemble the pick up unit. since radiation from exposed laser diode is dangerous.
2. Do not adjust the variable 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 look at pick up lens for a long time.

Page 12

SL-EH750

Remove the pulley gear, change gear and UP/DOWN gear.

UP/DOWN gear

Pulley gear ->@

Change gear
,/

Bottom/position SW RC.B.
LI n Release the 2 claws,
.-.

and then remove the
bottom/position SW
P.C.B..

133-»

Release the claw, and then
remove the tray lock.

Tray lock

install the tray lock spring to
the hook temporally.

Tray lock spring

Release the claw, and

then remove the rear
lock.

Take care not take the

rear lock spring off.

Pressing the claw (B) in the direction of arrow (D,
force the connection lever in the direction of arrow ®.

Connection
lever

-12-