Sony str av 270x service manual

Page 2

STR-AV23/AV270X/AV370X/AV57OX

General
System

Tuner section:PLL quartz»locked digital synthesizer system
Preamplifier sectionflowmoise NF type equalizer amp
Power amplifier sectionzquasicomplemetary SEPP

Power requirements

120V AC. 80 Hz

Power consumption
us model Canadian model
STR STR-AV370X - 155W
srR-sza _
AV270X W

STR~AV570XIAV231 In standby condition: 5W

AC outlets

One switched (120 W/1A Max)

Dimensions

Approx. 430 x 122.5 x 300mm (th/d)
(17 X 4 7/8 X 11 7/8 inches)
including projecting parts and controls

Weight
sTR-AV570X Approx. 8.5 lg (14 lb 5 oz)
STR-AV23
AV270X Approx. 6 kg (l3 lb 4 oz)
AV370X

Accessories supplied

FM wire antenna (1)

AM loop antenna (1)

Remote Commander RM-5103 (1) (STR-AVZSIAV37oX/AV57OX)
Sony batteries SUM 3 (NS) (2) (STR-AV23/AV370XIAV570X)

Design and specifications subject to change without notice.

TABLE OF CONTENTS

Section M Page
1. GENERAL

Location and Function of Controls ~~~~~~~~~~~ 3

Receiving FM/AM Broardcasts ~~~~~~~~~~~~~ 4
2. ELECTRICAL ADJUSTMENTS ---------- 6
3. DIAGRAMS
3.1. Block Diagram ........................... 7
3-2. Printed Wiring Boards -- Main Section - ~ 11
3-3. Schematic Diagram - Main Section - 15
3-4. Printed Wiring Boards - Tuner Section -- ~ ~ 19
3-5. Schematic Diagram - Tuner Section - ~~~~~ 20
36. Explantion of IC301 ( flPD75206) ---------- 23
4. EXPLODED VIEWS . A - . --------------- 25
5. ELECTRICAL PARTS LIST ~~~~~~~~~~~~ 27

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, metaliized
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 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 at 2V AC range are
suitable. (See Fig. A)

To Exposed Metal
Part: on Set

AC
voltmeter
(0, 75 V)

0.75pF

Earth Ground

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