Technics RSM 270 X Service Manual

Page 1

ORDER NO. ARD81030031C8-24i

Service Manual

Cassette Deck

db): Equipped Direct Drive Cassette Deck RS_M27OX

with Peak Hold FL Meters, Solenoid Controls (Silver Face)
and Dolby Noise Reduction Black Face

This is the Service Manual for the
following areas.
El -------- For all European areas

do-

except United Kingdom.
--------- For United Kingdom,
,r [I ......... For Australia.

.. #1:. . ..
. A?

p...

RS-M85 MECHANISM SERIES

Specifications
Track system 4etrack 2-channel stereo recording and playback lnputs: MIC; sensitivity 0.25 mV. input impedance 100m
Tape speed' 4,8cm/s applicable microphone impedance 4009 710kS2
Wow and tlutter. 0.035% (WRMS). :o.1% (DIN) LINE. sensitiwty 60 W input impedance 47kg
E ; M t lt , 2072O,OOOH Outputs LINE; output level 400 mV output impedance
requency response e a ape 25718 000 H; (DlN) 2,5k52 or less, load impedance 22 k9 over
30171000Hz i3dB HEADPHONES; output level 125 mV, load impede
CrOp tape; 20719.000Hz _ me 89
25 -'18.000Hz (DlN) Bias frequency 85 kHz
30716.000Hz t 3 dB Motor: Zemotor system
Normal tape; 20 717,000 Hz 1-FG servo controlled direct-drive DC motor
25716.000Hz (DlN) LDC motor tor reeltable drive
30 715000 Hz :3dB Heads, 2-head system
Dynamic range 110dB (at 1kHz) 1-SX (SendustExtra) head for record/playback
Max input level' 10 dB or more improved with db; in (at 1kHz) lesendust/ferrite doublergap head lOV erasure
Signal-tornoise ratio: dbx in: 92 dB Power reqwrement: AC, 110/125/220/240 V, 50760 Hz
Dolby NR in' 68 dB (above SkHz) Preset power voltage 240V tor Australia and
Dolby NR out; 58 dB (signal |eve|:rna><. record, Ull'led Kingdom
ing level, 00, type tape) Power consumption 30W
Fast forward and DimenSions: 43.0cm (W) X9.8cm(H) >< 35.0cmlD)
rewind time Approx 85 seconds with 060 cassette tape Weight: 6 2 kg

Specifications are subject to change without notice.
» The term dbx is a registered trademark of dbx lnc
u Dolby and the doubleeD symbol are trademarks of Dolby Laboratories

I I I h . Matsushita Electric Trading Co., Ltd.
ec nlcs PO, Box 288, Central Osaka Japan

Page 2

RS- M270X

CONTENTS

ITEM PAGE
LOCATION OF CONTROLS AND COMPONENTS ------------------- 1
DISASSEMBLY INSTRUCTIONS ....................................... 2
MEASUREMENT AND ADJUSTMENT METHODS

(WITHOUT dbx SYSTEM) ............................................. 3

OUTLINE OF dbx SYSTEM ----------------
THE BLOCK DIAGRAM OF dbx SYSTEM
MEASUREMENT AND ADJUSTMENT METHODS
(FOR dbx SYSTEM) ..............................................
'TROUBLESHOOTING CHART FOR dbx SYSTEMW ---- 11
0 ADJUSTMENT PARTS LOCATION OF dbx SYSTEM -------- 12
' SIGNAL WAVE FORMS AT INDIVIDUAL SECTIONS
OF THE RMS DETECTOR CIRCUIT & VCA CIRCU|T~~
0 dbx SYSTEM CHECKING METHOD >
' ADJUSTMENT 0F dbx SYSTEM ------
'CHECKING PROCEDURE FOR PROBLEMS -
ELECTRICAL PARTS LOCATION ....................................... 14
SCHEMATIC DIAGRAM
MAIN AMP SECTION ......................

12

................ 15

ITEM

CIRCUIT BOARD

MAIN AMP CIRCUIT BOARD u

FL METER CIRCUIT BOARD
SCHEMATIC DIAGRAM

dbx SECTION ...........................................................
CIRCUIT BOARD

dbx CIRCUIT BOARD
SCHEMATIC DIAGRAM

POWER SUPPLY & MAIN CONTROL SECTION ------------ 19
CIRCUIT BOARD
POWER SUPPLY & MAIN CONTROL CIRCUIT BOARD~~ 20

SCHEMATIC DIAGRAM

CAPSTAN MOTOR SECTION u
WIRING CONNECTION DIAGRAM >
MECHANICAL PARTS LOCATION ~-
CABINET PARTS LOCATION

LOCATION OF CONTROLS AND COMPONENTS

Tape Counter and Reset Button (tape counter) *fl

Cassette Holderfi

Eiect Button (eject) ifl

fi-Fluorescent Meter

fi Noise Reduction Selector Switch
[Noise Reduction
(Dolby NR out . Ijlape - .disc)]

Input Level Controls

Power Switch 7
[power (push on)]
Headphones Jack
(phones)

é]
fl
©

(input level) (L9H)

~7Microphone Jacks '
[mic (IeIt-righm

Record Button with Record Indication Lampi
[rec (0)]

Rewind Button (raw) (4)
Stop Button [stop (I)

Playback Button with Playback Indication Lamp 7*/

[Play (NI
Fast Forward Button [if (y )1]

Pause Button with Pause Indication Lamp;

[pause( II )I

gTimer Start Switch (timer rec I)
(lowlan)

PInput Selector (input select)
(1|ine.nmic)

-dbx Display LamN )

LOutput Level Control (output level)

Tape Selector
Record Muting Button(rec mute)(0) Q [tape select(normal-Fe-Cr.croz.Metal)I
T: l|||ll||||||||||||||l||l||| 7
i 9?] IIIlIlIIIIIIIIIIIIIIIIlllfll [j Voltage Salem

I)? a

(VOLTAG E SELECTOR)

_ Power Cord

S

Line OutputJacks (LINE our) (Fl- Ll4j

Line Input Jacks (LINE IN) (Rt DJ

III

Remote-Control Connector
(REMOTE CONTROL)