Sony str av 770x service manual

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STR-AV770X

AM tuner section

Frequency range US. Canadian model: 530 -- 1,7Io kHz

UK model: 531 - 1.602 kHz

Antenna Loop antenna

Usable sensitivity 50 dB/m (at 1.000 kHz or 999 kHz)

SIN 54 dB (at 50 mV/m)

Harmonic distortion 0.5% (50 mV/m, 400 Hz)

Selectivity 35 dB (9 Id-Iz). 40 dB (10 kHz)

Auto tuning threshold 55 dBlm

Video section

Inputs VIDE01.2: 1 Vp-p 75 ohms
Outputs VIDEO 1. MONITOR: 1 Vp-p 75 ohms
General

System Tuner section

PLL quartz-locked digital synthesizer system

Preamplifier section Low-noise NF type equalizer

Power amplifier Quasi-complimentary SEPP
section

Power requirements USr Canadian model: 120 VAC. 60 Hz

UK model: 240 VAC. 50 Hz

Power consumption 200 watts
AC outlets One switched. total 100 W Max
Dimensions 430 x 135 x 355 mm

(7 X 5 3/8 x 14 inches)
Weight 9.7 kg (21 lb 6 oz)

TABLE OF CONTENTS

Section M Page
Specifications .................................. 1
Safety Check-out ............................... 2
1. GENERAL
Pans Identification ........................ 3
Connections . . ............... . ..... . . . . . . 5

2. ELECTRICAL ADJUSTMENTS

FM SCCIIOH .............................. 6
3. DIAGRAMS
3.1 Block Diagram ........................... 9
3-2. MAIN Section Printed Wiring Boards - l4
3-3. MAIN Section Schematic Diagram ---------- 19
3-4 DISPLAY Section Printed Wiring Boards

and Section Schematic Diagram ~~~~~~~~~~~~~ 24
3-5. TUNER Section Schematic Diagram . 27
3-6. TUNER Section Printed Wiring Board - 29
4. EXPLODED VIEWS -------------------- 3O
5. ELECTRICAL PARTS LIST ------------ 32

SA FETV-RELATED COMPONENT WARNING

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.

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 aeross a resistor by
means of a VOM or battery-operated AC volt-
meter. The limit" indication is 0.75 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 2V AC range are
suitable. (See Fig. A)

To Exposed Metal
Part: on Set

Ac
0.15mr gum / voltmeter
(0.75VI

? Earth Ground

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

ATTENTION AUCOMPO'SANT AYANT RAPPORT
A LA SECURITE!

LES COMPOSANTS IDENTIFlés PAR um: MAROUE A
sun LES DIAGRAMMES SCHEMATIOUES ET LA LISTE
DES PIECES sou-r CRITIQUES POUR LA sécunrre
DE FONCTIONNEMENT. NE REMPLACER ces cOM-
POSANTS cue PAR DES PIECES sonv DONT LES
NUMEROS sour ooNNés DANS cs MANUEL ou
DANS LES SUPPLEMENTS PUBLIES PAR SONY.

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