background image
MICROFILM
SERVICE MANUAL
FM/AM CLOCK RADIO/
HOME SECURITY LIGHT
CONTROL SYSTEM
US Model
Canadian Model
E Model
SPECIFICATIONS
ICF-C900HS
Ver 1.0 1998. 07


background image
­ 2 ­
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
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFIÉS PAR UNE MARQUE
! SUR
LES DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES
PIÈCES
SONT
CRITIQUES
POUR
LA
SÉCURITÉ
DE
FONCTIONNEMENT. NE REMPLACER CES COM- POSANTS
QUE PAR DES PIÈCES SONY DONT LES NUMÉROS SONT
DONNÉS DANS CE MANUEL OU DANS LES SUPPLÉMENTS
PUBLIÉS 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.
CF3
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 it's 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, "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
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 "limit" 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
0.15
µF
AC
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Earth Ground


background image
­ 3 ­
SECTION 1
GENERAL
This section is extracted from
instruction manual.


background image
­ 4 ­
Note: Follow the disassembly procedure in the numerical order given.
SECTION 2
DISASSEMBLY
1 three screws
(BTP3
× 20)
2 knob (alarm)
3 cabinet (upper) section
1 two screws
(BTP3
× 20)
1 two flat wire
(CN1, 3)
1 speaker wire
(CN1)
6 MAIN board
7 battery snap
3 two claws
5 three claws
2 holder (transformer)
4 SWITCH board
CABINET (UPPER) SECTION
MAIN/SWITCH BOARD


background image
­ 5 ­
2 power cord
1 transformer (T102)
power cord
FM wire antenna
1 pointer
2
3
6 three claws
4 knob (tuning)
When installing, knob (tuning) adjust the
marking (B) hole and pointer boss.
5 Turn variable capacitor
(CV1) shaft and
knob (tuning) in the
arrow direction fully.
boss
B
7 MAIN board
variable capacitor
(CV1)
knob (tuning)
marking (B) hole
TRANSFORMER (T102)
DIAL POINTER SETING
Note: Follow the assembly procedure in the numerical order given.
Note: When installing, position the power coad as shown in the figure.