Sony tc rx 70 service manual

Page 1

SERVICE MANUAL

Dolby noise reduction manufactured under license from

Dolby Laboratories Licensing Corporation.
"DOLBY and the doubleAD symbol DI] are trademarks of
Dolby Laboratories Licensing Corporation.

SPECIFICATIONS

Recording system 4~track Zchannel stereo

Fast winding Approx. 90 sec. (with 060 cassette)
Bias AC Bias
Signal-to-noise ratio (NAB. at peak level)
DOLBY ,NR BvTYPE GTYPE
swnch OFF ON ON
Cassette
Type IV (Sony
MET AL-ES) 59 dB 67 dB 74 dB
Type II (Sony UX-S) 58 dB 66 dB 73 dB
Type I (Sony HF-S) 56 dB 64 dB 71 dB

Total harmonic distonion
1.0 % (with Sony METALES cassettes)

Frequency response
DOLBY NFl OFF
0 With Type IV cassette (Sony
MET ALES)
RX7OE$ : 20-20000 Hz (i3 dB)
RX70 : 25-19000 Hz (1' 3 dB)
30-15900 Hz (:8 dB, OVU recording)
- With Type II cassette (Sony UX~S)
25-11000 Hz (:3 dB)
15- 18,000 Hz
0 With Type | cassette (Sony HF-S)
25-1e,ooo Hz(13 dB)
15-17900 Hz
006% WRMS (NAB)
Microphone inputs (phone jacks)
Sensitivity 0.25 mV (-70 dB)
For a low-impedance microphone
Line inputs (phono jacks)
Sensitivity 77.5 mV (- 20 dB)
Input impedance 47k ohms

Wow and flutter
lnputs

US Model
Canadian Model
UK Model

TC - RX7OES

AEP Model

TC-RXIO

Model Name Using Similar Mechanism New Mechanism

Tape Transport Mechanism Type TCM-200D2

Outputs

Line outputs (phono jacks)
Output level of 0.44 V (~5 dB) at
a load impedance of 47k ohms
Load impedance of over 10k ohms
Headphones output (stereo phone jack)
Output level of -28 dB at a load
impedance of 8 ohms

General

Power r

equirements
RX70E$ 2120 V AC. 60H: (US, Canadian models)
240 V AC. 50H: (UK model)
RX70:220 V AC. 50/60Hz (AEP model)

Power consumption

Dimens

Weight

23 W
Approx. 430 x 123x 285 mm (wlh/d)

(17 X4, x1174 inches)
including projecting parts and controls
Approx. 4.6 kg (10 lbs 3 oz)

IONS

Supplied accessory

Connecting cord (2)

Optional accessory

Design
notice.

Remote commander RM0901

and specifications are subject to change without

STEREO CASSETTE DECK
SONY;

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TC- RX70/ RX70ES

TABLE OF CONTENTS

Section Title Page
Specification ........................ . ................. 1
Model Identification. -
Safety Check-Out .................................... 2
1. GENERAL .......................................... 3
2, DISASSEMBLY ..................................... 4
3.ADJUSTMEN1-s ..................................... 7
8- 1. Mechanical Adjustment --------------------- 7
3-2. Electrical Adjustment ........................ 7
4. DIAGRAMS
4- l. SemiconductorLead Layout ~~~~~~~~~~~~~~~~ 11
4-2. Circuit Boards Location -------------------- 12
4~3. Printed Wiring Boards ~~~~~~~~~~~~~~~~~~~~~ 13
4-4. Schematic Diagram - 17
5. EXPLODED VIEWS ............................... 19
5- 1 Front Panel Section ........................ 23
5-2. Chassis Section 24
5-3. Mechanism Section (TCM-ZOORZ) ---------- 25
5-4. Mechanism Section (TCM-ZOORZ) ---------- 26
6. ELECTRICAL PARTS LIST ....................... 27

MODEL IDENTIFICATION
~ Specification Label -
TC- RXIO

TC- RX70ES

SAFETY CHECK-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.

I. A commercial leakage tester, such as the
Simpson 229 or RCA WT-54OA. 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 voll-
meter. The limit indication is 0.75V, 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 2V AC range are
suitable. (See Fig. A)

SONYG

MODEL No. ///////////,

To Exposed Metal
Part: on Set

-_l

AC
0.15uF 1.5km / voltmeter
I0. 75 VI

7" Earth Ground

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

STER EO CASSETTE DECK

SERIAL NO.
MADE [N JAPAN

US, Canadian Models: AC 120V 60Hz 23W
UK Model: AC 240v rUse/60H:
AEP Model: Ac 220v mac/60H:

SAFETY-RELATED COMPONENT WARNINGII

COMPONENTS IDENTIFIED BV 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 PUB-
LISHED BY SONY.

ATTENTION AUCOMPOSANT AVANT RAPPORT
A LA SECURITEI

LES COMPOSANTS IDENTIFIES PAR UNE MAROUE A
SUR LES DIAGRAMMES SCHEMATIOUES ET LA LISTE
DES PIECES sour camoues POUR LA sécumré
DE FONCTIONNEMENT. NE REMPLACER ces COM-
POSANTS oue PAR DES PIECES sonv DONT LES
NUMéRos sour DONNES DANS ce MANUEL ou

__2_ DANS LES SUPPLEMENTS Puaués PAR SONY.