Sony tc k 490 service manual

Page 1

-K490

SERVICE MANUAL

- Dolby noise reduction and HX Pro headroom extension maniactured under
license from Dolby Laboratories Licensing Corporation. HX Pro originated by

Bang & Oiuisen.

DOLBY, the doublevD symbol DD and HX PRO" are trademarks of Dolby

sow:

Laboratories Licensing Corporation,

AEP Model
UK Model

Recording system
Fast winding time
Bias

Heads

Motors

SPECIFICATIONS

4vtrack 2-channel stereo

Approx, 90 sec (with Sony 0-60 cassette)
AC bias

Erasing head x 1 (S&F head)

Recording head x 1 (SD head)

Playback head x 1 (SD head)

capstan motor x 1 (DC servo motor)
Reel motor x 1 (DC motor)

Model Name Using Similar Mechanism NEW

Tape Transport Machanism Type TOM-1 90VB11

SignaHo-noiso ratio (at peak level)

Cassette
(Dolby NR OFF)

Type IV (Sony Type II Type I
Metal-S) (Sony UX-S) (Sony HF-S)
60 dB 59 dB 57 dB

Measured at peak level weighted without NFt. The SIN is improved by about
15 dB at 500 Hz and by about 20 dB about 1 kHz with Dolby-C NFi on, and by

5 dB at 1 kHz and by 10 US about 5 kHz with Dolby-B NFt ont

Harmonic distortion

031% (with Sony Type l, 160 nWb/m

315 Hz,.3rd H.D.)

15% (with Sony Type W. 250 nWb/m

315 Hz, 3rd HD)

Frequency response (DOLBY NFt OFF)

Type IV cassette
(Sony Metal-S)

30 - 19,000 Hz (:3 dB. IEC)
30 ~ l6,000 Hz [:3 dB (-4dB recordin9)j

Type II cassette
(Sony UX-S)

30 - 18,000 Hz (:3 dB, IEC)

Type I cassette
(Sony HF~S)

30 - 17.000 Hz (:3 dB( IEC)

Wow and flutter

i 0.15% WPeak (IEC)
007% WtRMS (NAB)
i 0.18% W.Peak (DIN)

Inputs
Line inputs Sensitivity (116 V
(phono lacks) Input impedance 47 k ohms

Outputs
Line outputs Rated output level 0.5 V at a load impedance
(phone jacks) of 47 k ohms

Load impedance Over 10 k ohms

Headphones Output level 1 mW at a load impedance
(stereo phone jack) pl 32 ohms

General

Power requirements AEP Model :

Power consumption
Dimensions
Weight

Supplied accessories
Optional accessory

220 - 230 V AC, (or 240 V AC
adjustable by Sony personnel),
50/60 Hz
UK Model :
240 V AC (or 220 V AC adjustable by
Sony personnel). 50/60 Hz
18 W
Approx 430 x 123 x 300 mm (w/h/d)
(17 x 47/; x 117/9 inches)
including projecting parts and controls
Approx. 4 kg (8 lbs 14 02)

Audio connecting cords (2)

Wireless remote control unit RM-J701

Design and specifications are subject to change without notice,

Note

This appliance coniorms with EEC Directive 87/308/EEC regarding

intenerence suppression.

STEREO CASSETTE DECK
S 0 NM

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TC-K490

TABLE OF CONTENTS
Section E 5%: Section [Lt-l: Eagl
Specifications ............................................................... 1 3. DIAGRAMS
6-1, Circuit Boards Location ------------------------------------- 14
1 GENERAL 6-2, Printed Wiring Boards . 15
Identifying the Parts 6-3. Shemaric Diagram ~~~~~~ ~~ 19
Recordingiii
. DISASSEMBLY . EXPLODED VIEWS
2_l , Front Panel ....................................................... 5 7,1 Chassis Section ................................................ 25
2-2. Mechanism Deck ~~ ~-~5 7-2, Front Panel Section
2-3. Head ~~~~~~~~~~~~~~~~ ~~~6 7-3. Mechanism Sectionl- ~-
2-4. Fitting Base Block "'6 7-4. Mechanism SectionZ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 28
2-5. Motor ~~~~~~~~~~~~~~~ W6
. ELECTRICAL PARTS LIST ................................... 29
. BLOCK DIAGRAM ................................................. 7
. EXPLANATION OF IC TERMINALS ~~~~~~~~~~~~~~~~~~~~~~~ 9

A ADJUSTMENTS
5-1, Mechanical Adjutmentsm
5-2. Electrical Adjustments ~

MODEL IDENTIFICATION
(Specification Label)

SONYa

STEREO CASSETTE DECK

MODEL NO. Tc-K490

AEP model 2 AC 220-230V~50 / 60HZ
UK model 2 AC 240V~50 / 60HZ

SAFETY-RELATED COMPONENT WARNINGII

COMPONENTS IDENTIFIED BY MARK A OR DOTI'ED
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.