Technics RSBX 747 Service Manual

Page 1

Service

Stereo Cassette Deck

DEI-

RS-TR555 MECHANISM SERIES (AR350)

SPECIFICATIONS

I CASSETTE DECK SECTION

Deck system Stereo cassette deck

Track system 4-traok, 2-channel

Recording system AC bias
Bias frequency 80 kHz

Erasing system AC erase

Heads Recording head [Permaiioy (combination)]x1

Playback head [Permalioy (combination)]x1
Erasing head (Double-gap ferrite)x1

Motors
Capstan drive (Quartz DD MOTOR)><1
Reel table drive (DC MOTOR)?<1
. Cassette holder open/close (DC MOTOR)><1
Tape speed 4.8 cmlsec. (1 -7/a ips)
Wow and flutter

0.05% (WRMS)
i0.14% (DIN)
Fast forward and rewind times
Approx. 50 seconds with 0-60 cassette tape
Frequency response (Dolby NR off)

NORMAL so Hz-17 kHz, i3 dB
20 H24 8 kHz (DIN)
CrO: so Hz-18 kHz, :3 dB
20 Hz-1 9 kHz (DIN)
METAL so Hz.-19 kHz, i3 dB

20 Hz-20 kHz (DIN)

Technics

ORDER NO. AD930516002

anual

Cassette Deck

RS-BX747

Colour
Area
13:51:); if; Area Colour
(E) Europe.
(EB) Great Britain. (K)
(EG) Germany and Italy.

a: Dolby noise reduction and HX PRO headroom extension
manufactured under license from Dolby Laboratories
Licensing Corporation. HX PFlO originated by Bang and
Olufsen. Dolby, the double-D symbol, and HX PRO are
trademarks of Dolby Laboratories Licensing Corporation.

SIN (Signal Ievei=max recording level, Cro: type tape)

NH off 57 dB (A weighted)

Dolby 8 NR on 66 dB (A weighted)

Dolby c NR on- 74 dB (A weighted)
input sensitivity and impedance

REC (W) 100 mV/47 ko
Output voltage and impedance

PLAY (OUT) 500 mVISODQ

HEADPHONES 190 mV/(BQ)

(Load impedance 80-6000)

I GENERAL
Power consumption 23 v
Power supply AC 50 H2160 Hz, 230 V-240 V
Dimensions (WXHXD) 430x125x293 mm
Weight 4.6 kg
Note:

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

Page 2

RS-BX747

I CONTENTS

ACCESSORIES .
CONNECTIONS
CAUTION FOR AC MAINS LEAD
FRONT PANEL CONTROLS AND FUNCTIONS
PLAYBACK (Basic play)
DISASSEMBLY INSTRUCTIONS
ADJUSTMENT PROCEDURE
MEASUREMENTS AND ADJUSTMENTS
TROUBLESHOOTING GUIDE
TERMINAL FUNCTION OF IC.
BLOCK DIAGRAM .................

I ACCESSORIES
AC power supply cord ................................. 1pc.
(VJAO733) ............ (EB) (RJA0019-2K) ...... (E, EG)

Page
SCHEMATIC DIAGRAM .. 31 ~40
TROUBLESHOOTING OF E OTOR ............. 39, 40
TERMINAL GUIDE OF lcS TRANSISTORS AND DIODES ...... 31
PRINTED CIRCUIT BOARDS ..... . ~44

WIRING CONNECTION DIAGRAM ..... 45

INTERNAL CONNECTION OF FL
CABINET PARTS LOCATION
REPLACEMENT PARTS LIST
PACKAGING
MECHANISM PARTS LOCATION.
RESISTORS AND CAPACITORS ..

X TECHNICAL INFORMATION

This technical information is located on pp 45-51 of the

RS-3555 Service Manual (Order No. AD8907231CS).
Therefore, refer to that Service Manual.

There is a few differences in this schematic diagram.
But this is the same as its-3555 basically.

Stereo connection cables ............................. 2pcs.
(SJP2276)

ICONNECTIONS

Make connections in the numbered sequence by using the included
cables.

Rear panel
of this unit

neqm) puvroun

Household
AC outlet

Amplifier or receiver
(not included)

REC PLAY
(OUT) (IN)

The above illustration shows an example of connections made
when this unit is combined with a Technics hi-fi component system,
and shows only the connections to be made to and from this unit in
that combination.

III Connect the stereo connection cables.

FOR UNITED KINGDOM ONLY
BE SURE TO READ THE CAUTION FOR AC
POWER SUPPLY CORD ON PAGE 3 BE-
FORE PROCEEDING TO THE STEP 2.

[El Connect the AC power supply cord after you
have connected all other cables and cords.
The configuration of the AC outlet and AC power supply cord
differs according to area.

Insertion of Connector

Even when the connector is per-
fectly inserted, depending on the
type of inlet used, the front part of
the connector may iut out as
shown in the drawing

However there is no problem
using the unit.

Connector

r ..
Approx. 6 mm
Appliance inlet

Note:
Avoid letting the cables touch each other as much as possible,
otherwise noise will be generated.

Placements hints

it this unit is placed near a receiver or a tuner, a hum" noise may
be heard during tape playback, recording, or AM reception of the
receiver or the tuner.

if this occurs, leave as much space as possible between the units.
or place them where is the least amount of "hum",

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Page 13

t l

RS-BX747

1. Release the 2 claws in the direction of arrow®.

Ref.No. . . Ref.No. Removal of the switch lever and
19 Removal of the Intermediate gear 20 ATS arm
Procedure Procedure
1-»2->6->12 1->2->6->12 Claw
a16->17->18 ->1e->17->13
" 19 Intermediate gear -* 19 ~> 20

I Removal of the swltch lever

0 Release the 1 claw and then remove the switch lever in
the direction of arrow ©.

l Removal of the ATS arm

- Release the 1 claw and then remove the ATS arm in the
2. Remove the Intermediate gear in the direction of arrow®. direction of arrow®.
Ref.No. Removal of the mechanism base assy, mecha shield plate, loading base assy and
21 mechanism unit
Procedure
1 -> 2 ->6 -> 10
-> 1 2 -> 21

o
3

Head lead wire

09

--eol

O/©

Claw

\_,'
\e
9

1. Remove the 3 screws(0~9) .
2. Remove the head lead wire from claw.

Loading base ass'y

Mechanism unit

5. Remove the 1 screw(e) .

6. Remove the 2 ribs and then remove the mechanism unit
in the direction of arrow©.

Mechanism base assy

E?

Mecha shield plate

3. Remove the mechanism base assy in the direction of
arrow©.

4. Remove the mecha shield plate in the direction of arrow®

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Page 19

l

ITERMINAL FUNCTION OF IC

0 IC503 (M38172M2500F): MICROCOMPUTER

*To check the contents of the item X" in the IC terminal table, set the unit to the state
described in the Motor Control PCB Checking Method" on page 15.

RS-BX747

Pin

IIO

No. Mark Division Function Check point X Discrrption
Changes within the 0 H
. 3V range each time the
Real pulse det. Input Connector av - .

1 RPT I (take up side) W507 ® pin 0 take up reel rs through
approxrmately 30
degrees.

Changes within the 9 e
, 3V range each time the
Reel pulse det. Input (supply Connector av .

2 RPS l side) W507 ® pin 0 take up reel rs through
approximately 30
degrees.

3 DOOR I Cassette holder half det. Connector Tape in: 5V

input (photo det.) W501 pin Tape out: 0V

Key switch (COUNTER

RESET, COUNTER MODE,

MEMORY REPEAT/STOP, Connector +5V without key Input and 0V with the stop key

4 KEY2 l POWER, DOLBY B, DOLBY 3503 @ 'n 0N. An analog value (0~5V) is used for each

0, MPX, ATC ON/OFF, ATC 9' key ON.
SELECT, TIMER REC/PLAY)
input
A tew hundred us
DA converter data output Connector i"'-I
5 SDAC O , , . 5v Usually
ON: "L OFF: H' CP3
' G) p' o JWLJNL
A few hundred us
DA converter serlal clock Connector l_l
5v
6 SCKC 0 output ON: ,1. OFF: H CPS © pin 0 MM NM sua'w
A few .15 A few hundred us
7 STBC 0 DA converter strove signal Connector 5v 44! Usuall
output 0N: H, OFF: L" 0P3 © pin J-L-H- y
o
, . L (=0V) when sound is being producedin the
8 DMT 0 336 3:: offisfl'fiffl' output gggnéctci: play or REC mode and H (=5V) when no sound
' ' p is produced in the stop or FF/REW mode.
9 Es
- Not used - Connected to GND
10 CLK1
11 OPICL SW I Can switch of eject Connector Cassette holder open/close condition: 0V
mechanism input W501 (:9 pin Cassette holder active: 5V
. H" (=5V) when deck is in the high-speed
High speed take up selector Connector .l u _ .

12 HSPD 0 output of reel motor W501 ® pin FF/FiEW or TPS mode and L (~0V) In other

modes.

13 SDIK uo Egfifigmcgiffiilff; Signal gaggzcggin 5v @ms $123: '{QIthzl-gp

, - o .

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