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TABLE OF CONTENTS
1. GENERAL
.................................................................. 3
2. DISASSEMBLY ......................................................... 4
3. ELECTRICAL ADJUSTMENTS ........................ 6
4. DIAGRAMS ................................................................ 8
4-1. Block Diagram ................................................................ 8
4-2. Printed Wiring Boards ..................................................... 10
4-3. Schematic Diagram ......................................................... 13
4-4. IC Pin Function Description ........................................... 17
5. EXPLODED VIEWS ................................................ 19
6. ELECTRICAL PARTS LIST ............................... 21
ATTENTION AU COMPOSANT AYANT RAPPORT
Ë LA SƒCURITƒ!
LES COMPOSANTS IDENTIFIƒS PAR UNE MARQUE ! SUR
LES DIAGRAMMES SCHƒMATIQUES ET LA LISTE DES
PIéCES SONT CRITIQUES POUR LA SƒCURITƒ DE
FONCTIONNEMENT. NE REMPLACER CES COM- POSANTS
QUE PAR DES PIéCES SONY DONT LES NUMƒROS SONT
DONNƒS DANS CE MANUEL OU DANS LES SUPPLƒMENTS
PUBLIƒS PAR SONY.SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR 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 PUBLISHED BY SONY.
CF 3
CF1 mark
Mark Center frequency
red 10.70 MHz
blue 10.67 MHz
orange 10.73 MHz
black 10.64 MHz
white 10.76 MHz
HOW TO CHANGED THE CERAMIC FILTERS
This model is used two ceramic filters of CF1 and CF3.
You must used same type of color marked ceramic filters in order
to meet same specifications.
Therefore, the ceramic filter must changed two pieces together
since itÕs supply two pieces in one package as a spare parts.
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing safety check before releasing the set to the customer:
Check the antenna terminals, metal trim, ÒmetallizedÓ 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 manufacturersÕ instructions to use these
instruments.
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 voltmeter. The ÒlimitÓ indica-
tion is 0.75 V, so analog meters must have an accurate low-
voltage scale. The Simpson 250 and Sanwa SH-63Trd are ex-
amples of a passive VOM that is suitable. Nearly all battery
operated digital multimeters that have a 2 V AC range are suit-
able. (See Fig. A)
Fig. A. Using an AC voltmeter to check AC leakage.
1.5 k W 0.15 µF AC
voltmeter
(0.75 V) To Exposed Metal
Parts on Set
Earth Ground
