Read Sony ICF-C121 Service Manual online
MICROFILM
SERVICE MANUAL
FM/AM CLOCK RADIO
US Model
Canadian Model
E Model
SPECIFICATIONS
ICF-C121
FEATURES
Ver 1.2 1999. 11
With SUPPLEMENT-1
(9-925-799-81)
With SUPPLEMENT-2
(9-925-799-82)
With SUPPLEMENT-1
(9-925-799-81)
With SUPPLEMENT-2
(9-925-799-82)
– 2 –
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.
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 PUB-
LISHED BY SONY.
OPERATION. REPLACE THESE COMPONENTS WITH
SONY PARTS WHOSE PART NUMBERS APPEAR AS
SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUB-
LISHED BY SONY.
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.
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
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.
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)
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
Ω
0.15
µ
F
AC
voltmeter
(0.75 V)
voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Parts on Set
Earth Ground
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-
• Notice that the minus side of a tantalum capacitor may be dam-
aged by heat.
SECTION 1
SERVICING NOTES
Mark 1 Mark 2
Center
frequency
red
—
10.70MHz
blue
—
10.67MHz
orange
—
10.73MHz
black
—
10.64MHz
white
—
10.76MHz
white
white
10.75 MHz
yellow
—
10.79 MHz
HOW TO CHANGE THE FM CERAMIC FILTERS
This model is used two ceramic filters of CF1 and CF3.
You must use same type of color marked ceramic filters in order
to meet same specifications.
Therefore, the ceramic filter must change two pieces together since
it's supply two pieces in one package as a spare parts.
You must use same type of color marked ceramic filters in order
to meet same specifications.
Therefore, the ceramic filter must change two pieces together since
it's supply two pieces in one package as a spare parts.
CF1
mark 2
CF3
mark 2
mark 1
CORD DRESSING
(POWER, ANTENNA, BATTERY)
(POWER, ANTENNA, BATTERY)
1) Connect the power cord, antenna cord, and battery cord as
shown in the figure.
2) Mount the chassis with screws (PTP3
×
10).
Note: Tighten completely the screws (PTP3
×
10).
battery cord
screw (PTP3
×
10)
antenna cord
power cord
chassis
– 3 –
SECTION 2
GENERAL
This section is extracted from
instruction manual.
instruction manual.
– 4 –
Note:
Follow the assembly procedure in the numerical order given.
SECTION 3
DIAL POINTER SETTING
1
pointer
5
As shown in figure,
marking
marking
A
of TUNE
knob and marking
B
of VOL knob setting.
4
screw
(P3
(P3
×
10)
8
RADIO board
2
Set the pointer to
the guide line.
the guide line.
3
chassis
7
Turn CV1 and RV1 shaft in
the arrow direction fully.
the arrow direction fully.
6
speaker
pointer
guide line
knob (TUNE)
knob (VOL)
marking
A
CV1
RV1
RADIO board
(Conductor Side)
(Conductor Side)
marking
B
