Sony tc k 370 service manual

Page 1

TC-K3TU/RX3TU

SERVICE MAN/HAL

/

Photo :TC- K370

" Dolby noise reduction and HX Pro headroom extension manufactured
under license from Dolby Laboratories Licensing Corporation. HX Pro
originated by Bang & Oluisenr

"DOLBY", the double-D symbol DE] and HX PRO are trademarks of Dolby
Laboratories Licensing Corporation.

AEP Model
UK Model
Australian Model

TC-K3 70

US Model
Canadian Model
AEP Model

TC-RX370

Model Name Using
Similar Mechanism

TC-W370/W41 1
/WR511/WR57O

SPECIFICATIONS

Tape Transport
Mechanism Type

TC-K37O
TC-RX370

TCM-T SOVBI 20
TOM-1 90RB12C

Recording system 4-track 2-channel stereo Outputs

Fast-winding time Approx. 90 sec. (with Sony 0-60

Line outputs

cassette) _
Bias AC bias mm lacks)
Motors Capstan motor x 1 (DC motor)

Reel motor x 1 (DC motor)

0.32 V at a load
impedance of
47 k ohms

Rated output level

Load impedance Over 10 k ohms

0.3 mW at a load
impedance 01
32 ohms

Output level

Signal-to-nolse ratio (at peak level) Headphones
Dolby NR switch OFF B-Type OType (stereo phone
Cassette ON ON jack)
Type lV (Sony METAL-5LT) 58 dB 66 dB 73 GE
General
Type M (Sony 0x6) 57 dB 65 dB 72 dB Power requiremems
Type I (Sony HF-S) 55 dB 63 dB 70 dB

Total harmonic distortion
1% (with Sony METAL-8LT cassette)
Frequency response (DOLBY NR OFF)

Power consumption

Type IV cassette 30 - 15,000 Hz (:3 dB, lEC) Dimensions
(Sony METAL-8LT) 30 - 13,000 HZ {:3 dB, OVU (-4 dB)

recording)
Type ll cassette 30 ~ 15 000 Hz :3 dB lEC Weight
(Sony UX»S) ( )
Type ' 0355 so - 14,000 Hz (:3 dB, lEC)
(Sony HF-S)

Wow and flutter 50.13% W. Peak (lEC)
0.07% WRMS (NAB)

10.18% W. Peak (DlN)

inputs
Line inputs Sensitivity 77.5 mV
(phone lac) lnput impedance 47 k ohms

US.Canadian model :lZDV AC.60H1
AEP,Germany,Austral ian model:
220~230V AC. (or 240V AC adjustable

by Sony personnel) 50/60Hz

UK model :240V 'AC. (or 220V AC adjustable
by Sony personnel) 50/60Hz

20 W

Approx. 430 x 123 x 287 mm (w/h/d)

(17 x 47/3 >< 113/3 inches)

including projecting pans and controls

Approx. 39 kg (8 lbs 10 oz)

Supplied accessory Audio connecting cords (2)

Design and specifications subject to change without notice.

STEREO CASSETTE DECK

ONY;

Page 2

TC-K370/RX370
SAFETY CH ECK-OUT

After correcting the original service problem,
perform the following safety check before releasing
the set to the customer:

Check the antenna terminals, metal trim, metallized
knobs, screws, and all other exposed metal parts for
AC leakage. Check leakage as described below.

LEAKAGE TEST

The AC leakage from any exposed metal part to
earth ground and from all exposed metal parts to any
exposed metal part having a return to chassis, must
not exceed 0.5 mA (500 microampers). Leakage
current can be measured by any one of three
methods.

1. A commercial leakage tester, such as the
Simpson 229 or RCA WT-540A. Follow the
manufacturers instructions to use these instru-
ments.

2. A battery-operated AC milliammeter. The Data
Precision 245 digital multimeter is suitable for
this job.

3. Measuring the voltage drop across a resistor by
means of a VOM or battery-operated AC volt-
meter. The limit indication is 075 V, so
analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa
SH-63Trd are examples of a passive VOM that
is suitable. Nearly all battery operated digital
multimeters that have a 2 V AC range are
suitable. (See Fig. A)

To Exposed Metal
Part: on Set

A C
voltmeter
(0.75 V}

0. 75uF 1. 5k!)

1- /
L.

? Earth Ground

Fig. A. Using an AC voltmeter to check AC leakage.

SAFETY-RELATED COMPONENT WARNING

COMPONENTS IDENTIFIED BY MARK A OR DOTTED
LINE WITH MARK A ON THE SCHEMATIC DIAGRAMS
AND IN THE PARTS LIST ARE CRITICAL TO SAFE
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBA
LISHED BV SONY.

TABLE OF CONTENTS

Section Title ELIE
SECTION 1. GENERAL """""""" r - 3
SECTION 2. DISASSEMBLY """"""" 4
SECTION 3. ADJUSTMENTS -------- . ----- 6
SECTION 4. DIAGRAMS
4'1. Circuit Boards Location~ - ------ 1]
4-2. Semiconductor Lead Layouts - ----- 11
4-3. Printed Wiring Boards- - - - - . . . .12
4-4. Schematic Diagram ----------- 15
SECTION 5. EXPLODED VIEWS
5 I. Chassis Section ------------ 19
5-2 Front Panel Section ---------- 20
5-3. Mechanism Section-1 ---------- 21
5 4. Mechanism Section-2 --------- - 22
SECTION 6 ELECTRICAL PARTS LIST -------- 23

MODEL IDENTIFICATION

(Specification Label)
TC-KSTO
TC-RXSTO

SONY»

STEREO CASSETTE DECK

WW

MODEL NO. Wm

US. Canadian model: ACIZOV 60Hz 20W
UK, Australian model: A0240v~50/60Hz
Germany, AEP model: A0220-230V~50/60Hz

ATTENTION AU COMPQSANT AYANT RAPPORT
A LA secumréi

LES coMPOSANrs IDENTIFIES PAR UNE MAROUE A
sun LES DIAGRAMMES SCHEMATIOUES ET LA LISTE
DES PIECES SONT CRITIQUES POUR LA sécumré
DE FONCTIONNEMENT. NE REMPLACER CES COM-
POSANTS QUE PAR DES Piécss SONV DONT LES
NUMEROS SONT DONNés DANS cs MANUEL ou
DANS LES SUPPLEMENTS PUBLIES PAR SONY.