Technics RSM 280 Service Manual

Page 1

ORDER NO. ARDBIO70071C8-34

Service Manual

Quartz-Locked Direct-Drive Stereo Cassette Deck
with 3Head, Double Capstan System

on-

RS-M250 MECHANISM SERIES

Specifications

Track system.
, Tape speed:
Wow and flutter:

Frequency response:

Signal-to-noise ratio:

Fast forward and

rewind time:

4-track 2-channel stereo recording and playback
4.8cm/s
0.024% (WRMS), i0.09% (DIN)
Metal tape; 18-22000 Hz
20 W, 20,000 Hz (DIN)
25*19,OOOH2 i3dB
18-21000 Hz
20-20,000Hz (DlN)
25-18,000Hz :3dB
18*20,0DOHZ

07719.000Hz (DIN)
25-17,000Hz i3dB
Dolby NR in; 70dB (above 5kHz)
Dolby NR out; 60dB

(signal leve|=peak level A weighted, Cr02
type tape)

Cr02 tape;

Normal tape;

Approx. 80 seconds with 060 cassette tape

lnputs:

Outputs :

Bias frequency
Heads:

Motor:

Power reqmrement'

Power consumption:

Dimensions:
Weight:

Specnications are subject to change without notice
t Dolby' and the doublerD symbol are trademarks of Dolby Laboratories.

Technics

Cassette Deck

RS-M280

(Silver Face)
Black Face

This is the Service Manual for the
following areas.
El --------- For all European areas l,
except United Kingdom, l
~For United Kingdom, l
. -- --»-For A5ia4 Latin America, l
l Middle East and Africa f
areas. l
-For Australia. l

MIC, sensitivity 0.25mV, input impedance 9m
applicable microphone impedance 4009* 10 kg

LINE; sensitivity 80 mV, input impedance 42 k9

LINE; output level 700 mV, output impedance
2.5 kg) or less load impedance 22 kg over

HEADPHONES; output level 125mV, load
impedance 89

85 kHz

3- head system

2 SX (Sendust Extra) beads for record/playback

1 double- -gap ferrite head for erasure

3-motor system

1 Quartz locked Direct Drive motor

2 DC motors for reel-table drive

AC; 110/125/220/240V, 50-60 Hz

EJII, 25W

: 20 W

43cm(W) X97 cm(H) X340 cm(D)

6 3 kg

Matsushita Electric Trading 00., Ltd.

PO. Box 288, Central Osaka Japan

Page 2

RS-M28O

CONTENTS
ITEM PAGE

LOCATION OF CONTROLS AND COMPONENTS ............................................. 2
DISASSEMBLY INSTRUCTIONS .................................................................. 3
BLOCK DIAGRAM ...................................................................................... 4
MECHANISM AND AMPLIFIER SYSTEM BASED
ON MICROCOMPUTER OF RS-M280 ............................................................ 4
MEASUREMENT AND ADJUSTMENT METHODS .......................................... 5
MN1400RZ: EACH TERMINAL FUNCTION & WAVEFORM ------------------------------ 11
TROUBLESHOOTING OF MAIN CONTROL CIRCUIT --------------------------------------- 15
DD MOTOR CIRCUIT CHECK POINTS ......................................................... 17
TROUBLESHOOTING OF D.D MOTOR CIRCUIT ............................................. 19
ELECTRICAL PARTS LOCATION .................................................................. 20
SCHEMATIC DIAGRAM

MAIN/FL METER/POWER SUPPLY SECTION ....................................... 21
CIRCUIT BOARDS

MAIN/FL METER/POWER SUPPLY CIRCUIT BOARDw --------------------------- 22
SCHEMATIC DIAGRAM

D.D MOTOR SECTION ........................................................................ 23
CIRCUIT BOARD

D.D MOTOR CIRCUIT BOARDS ............................................................ 23
SCHEMATIC DIAGRAM

MAIN CONTROL SECTION .................................................................. 24

CIRCUIT BOARD
MAIN CONTROL/KEY BOARD/REMOTE CONTROL JACK/

LED/SWITCH(S8, 9) CIRCUIT BOARD ................................................ 24
WIRING CONNECTION DIAGRAM ............................................................... 25
MECHANICAL PARTS LOCATION ............................................................... 25

CABINET PARTS LOCATION ........................................................................ 27