Sony tc wr 620 service manual

Page 1

SERVICE MANUAL

US Model
UK Mode/

Recording system

4-track 2»channe| stereo

SPECIFICATIONS

Model Name Using
Similar Mechanism

TC-W320
TC-WR520

Tape Transport

deck A: TOM-190RA12

Mechanism Type

deck B: TCM-lBORBlZ

Fast winding time Approx. 90 sec, (with HF-6O cassette)

Bias AC bias
Signal-to-noise ratio (NAB, at peak level)

Dolby NFi switch OFF B-TYPE C-TYPE
Cassette ON ON
TYPE IV
(Sony METAL-ES) 58 dB 66 dB 73 dB
TYPE ll
(Sony UX-S) 57 dB 65 dB 72 dB
TYPE |
(Sony HES) 55 dB 63 dB 70 dB

Wow and flutter
Inputs

0.07% WRMS (NAB)

Line inputs

Sensitivity

77.5 mV (20 dB)

(phono jacks)

Input impedance

50 kohms

Outputs

Line outputs
(phono jacks)

Rated output
level

0.44 V (-5 dB) at a
load impedance
47 kohms

Load impedance

Over 10 kohms

Total harmonic distortion
1.0% (with Sony METAL-ES
cassettes)

Frequency response (DOLBY NR OFF)

TYPE IV cassette 30-15,000 Hz (:3 dB)
(Sony METAL-ES) ISO-13,000 Hz (OVU recording)

TYPE ll cassette 30-15000 H2 (:3 dB)
(Sony UX-S)

TYPE l cassette
(Sony HF-S)

($014,000 Hz (:3 dB)

Headphones
(stereo phone
jack)

Output level

03 mW at a load
impedance of 32
ohms

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Dolby noise reduction manufactured under license from
Dolby Laboratories Licensing Corporation.
"DOLBY" and the doubleD symbol DU are trademarks of
Dolby Laboratories Licensing Corporation.

STEREfl CASSETTE DECK

SONY®

Page 2

' TC-WR620

General

Power requirements US model:
120V AC, 60Hz
UK model:
240V AC, 50Hz

Power consumption 26 Watts
Dimensions Approx. 430x135><285 mm (w/h/d)
(17x53/3x 111/. inches)
including projecting parts and controls
Weight Approx. 4.5 kg (9 lbs 15 oz)

Supplied accessory
Audio connecting cord (2)

MODEL IDENTIFICATION
-Specification Label-

SONYo MODEL N0. TC»WR620

STEREO CASSETTE DECK

W/l/ll/I/l/ll/d

SERIAL Nor
MADE IN JAPAN

US model: AC 120V 60Hz 26W
UK model: AC 240V~50Hz 26W

SAFETY-RELATED COMPONENT WARNING

COMPONENTS IDENTIFIED BY MARK & 0R DOTTED
LINE WITH MARK & 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.

SAF ETY CH EC K-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-540A. Follow the
manufacturers' instructions to use these instru-
ments.

to

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

3. Measuring the voltage drop across a resistor by
means of a VOM or batteryeoperated AC volt-
meter. The limit" indication is 0.7SV, 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)

To Exposed Metal
Part: on Set

AC

0. I5uF $1.5 m voltmeter
{0.75 VI

____l

'4 Earth Ground

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