Technics SLPS 740 A Service Manual

Page 1

ORDER NO. M59303041 C2

+ Service Manual

DIGITAL AUDIO

MASH*

mum- slag: not thplng

Compact Disc Player

SL-PS74OA

DIEIT/IL

Colour
(K) ........ Black Type
Areas
fi
[3:32; if; Area Colour
(E) Europe
(EB) Great Britain > (K)
(EG) Germany and ltaly

oTechnics (or Panasonic) developed the worlds first MASH
type DAC and AM) MASH technology was invented by
NTT (LSI Labs). ~

OMASH is a trademark of NTT.

SL-PG320A TRAVERSE DECK SERIES (RAD0301-1)

SPECIFICATIONS

I Audio

No. of channels 2 (left and right, stereo)
Frequency response 2-20.00!) Hz, 10.3 dB

Output voltage

Dynamic range

SIN

Harmonic distortion
Total harmonic distortion
Wow and flutter

DA converter

Output impedance

Load impedance
Headphone output level

2 v (at 0 dB)
100 dB

1 15 dB

0.0018% (1 kHz, 0 dB)
0,0023% (1 kHz, 0 dB)
Below measurable limit
MASH (1 bit)

6000.

More than 10 k9

15 mW max. 320 (adjustable)

Technics

II Pickup

Wavelength 780 nm

Laser Power No hazardous radiation is emitted
(with safety protection)

II General

Power consumption 10 W

Power supply AC 50/60 Hz, 230-240 V

Dimensions (WXHXD) 430x125x289 mm

Weight 4.6 kg

Notes:

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

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SL-PS740A

I CONTENTS

Page
HANDLING PRECAUTIONS FOR TRAVERSE DECK . MEASUREMENTS AND ADJUSTMENT 12~14
PRECAUTION OF LASER DIODE 3 TROUBLESHOOTING GUIDE ,. ,. 14~16
INSTALLATION 3 SCHEMATIC DIAGRAM ........ 17~22
ACCESSORIES 3 PRINTED CIRCUIT BOARD DIAGRAM 23N26
CAUTION FOR AC MAINS LEAD . 4 WIRING CONNECTION DIAGRAM . , . .. 27
LOCATION OF CONTROLS ................... . 5, 6 BLOCK DIAGRAM . . 28, 29
BASIC OPERATING PROCEDURE ............. . 6 FUNCTION OF IC TERMINALS. . 30~33
CONNECTIONS ............ 7 REPLACEMENT PARTS LIST 34~38
CLEANING OF LENS ........ .t 7 PACKAGING ................ .... 37
DISASSEMBLY INSTRUCTIONS . 8~11 CABINET PARTS LOCATION 39, 4O
CHECKING OFTHE SERVO RC B 11 LOADING UNIT PARTS LOCATION 41
CHECKING OFTHE MAIN P.C.B ................ 12

I HANDLING PRECAUTIONS FOR TRAVERSE DECK

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

Clip Snorting pln
IHandlIng ot traverse deck (optical pickup) : "1 F ' 1
1 . Do not subject the traverse deck (optical pickup) to static L_ _ J L94!
electricity as it is extremely sensitive to electrical shock.
2. To prevent the breakdown ol the laser diode. an anti-static _
shorting pin is inserted into the flexible board (FPC board). Be sure to short "5" portion
When removing or connecting the short pin. finish the job in as (Use the shorting 9' 0" I'm

short time as possible.
3. Take care not to apply excessive stress to the flexible board (F PC
board).

OGroundlng 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 conductive 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. 80, take care not to let your clothes touch the traverse
deck (optical pickup).

Lens (Do not touch) I,

Iron plate or some metals
to conduct electricity

I 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 uWNDE

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

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

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

4. Recommend not to lock at pick up lens for a longtime.

ACHTUNG: Dieses produkt enthalt eine laserdiode. lm eingeschalteten zustand wird unsichtbare laserstrahlung von der lasereinheit abgestrahlt.

Wellenlange: 780nm
Maximale strahlungsleistung der laserinhelt: 100 pW/VDE

Die strahlung an der Iasereinheit ist ungefahrllch, wenn tolgende punkte beachtet werden:

, Die Iasereinheit nicht zerlegen, da die strahlung an der freigelegten laserdiode gefahriich ist.
. Den werksseitig justierten einstellregler der lasereinreit nicht verstellen.

. Nicht mit optischen lnstrumenten in die fokussierlinse blicken.

. Nicht fiber langere zeit in die tokussierlinse blicken.

{IONA