Sony tcm 77 v service manual

Page 1

SERVICENUMAAL

US Model
Canadian Model

AEP Model
UK Model
E Model

SPECIFICATIONS

Recording system: 2-track t-channel monaural
Frequency response: 150-3 000 Hz (For normal tape TYPE l)
Power output (DC): 250 mW (at 10% harmonlc distortion)
Input: Microphone inputjack(minijack) sensitivity 0.2 mV for 3 kg or
lower impedance microphone
Output: Earphone iack (minijack) for 8-300 ohm earphone
Power requirements: 3 V DC, two size AA (R6) batteries
Dc IN 3 Vjack accepts:
Sony AC-77 AC power adaptor
1 20 V AC, 60 Hz
Sony DOC-70 car battery cord (not supplied) for use on 12 V car battery

Model Name Using Similar Mechanism NEW

Tape Transport Mechanism Type MT-77-44

Battery life:
Batteries Recording (hours)
Sony batteries SUM-3 (NS) Approx. 2
Sony alkaline batteries AM3 (N) Approx. 6

For maximum perbrrnance, we recommend the use of alkaline batteries.
Dimensions: Approx. 111.8 x 35.2 x 79.5 mm(wlhld)
(43/4 x 171.5 x 3% inches)
Inc. projecting parts and controls

Weight: Approx. 260 g (9.2 oz) incl. batteries
Accessories supplied: Carrying case (1)

Earphone mlcrophone (1)

AC pow2r adaptor (A077) (1) (US model only)

Note: Use only the recommended AC power adaptor or car battery cord
manufactured by Sony. Polarity oi the plugs of other manufacturers may
be ditlerent.

Polarity of the /
TOM-77V

Design and specifications subject to change without notice,

CASSETTE-BURDER
S 0 NY;

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TCM-77V I

FEATU R ES

. Auto-reverse function allows you to record or play-
back both sides of a cassette continuously without
turning the cassette over.

0 A large display window allows you to read indica-
tors easily.

0 Cue marker function to mark a desired portion dur-
ing recording.

0 VOR function allows you to record only when
sound is picked up.

0 Adjustable tape speed in playback mode.

- Equipped with a microphone sensitivity switch to
adiust the recording level depending on the micro-
phone you are using and the recording condition.

0 Safety HOLD switch to prevent the function but-
tons (REC, PLAY, FFICUE, PAUSE, HEW/REVIEW,
STOP, DIR) from being activated by mistake.

Secflzm

TABLE OF CONTENTS

Title Page

1. SERVICING NOTES

1-1. Method of Torque Measurement and
Tape Pass Check ............. . . .3

1-2. Service Mode .................................. 3
2. GENERAL

2-1. Parts Identification ............................ 4

2-2. Installing Batteries ............................ 4

2-3. Installing a Cassette . . , . . . . .. ................... 4

2-4. Recording ..................................... 5
3. DISASSEMBLY

3-1. Cabinet (Rear) .................................. 6

3-2. Cabinet (Front) ................................ 6

3-3. Gear (5 Reel, T Reel) Assy ...................... 7
4. MECHANICAL ADJUSTMENTS .............. 7
5. ELECTRICAL ADJUSTMENTS .................... 8
6. DIAGRAMS

6-1. Semiconductor Lead Layouts .................... 8

6-2. Printed Wiring Boards ................. , . .9

6-3. Schematic Diagram -Audio Section- ~13

6-4. Schematic Diagram -Display Section- ........ 16
7. EXPLODED VIEWS

7-1. Cassette Holder Block ........................ 19

7-2. Cabinet Block ................................ 20

7-3. Mechanism Block (1) .......................... 21

7-4. Mechanism Block (2) . ..................... 22
8. ELECTRICAL PARTS LIST ...................... 23