Sony ICF-C793 / ICF-C793L Service Manual ▷ View online
MICROFILM
SERVICE MANUAL
ICF-C793
FM/AM PLL SYNTHESIZED CLOCK RADIO
ICF-C793L
FM/MW/LW PLL SYNTHESIZED CLOCK RADIO
US Model
Canadian Model
E Model
Australian Model
ICF-C793
AEP Model
ICF-C793/C793L
UK Model
ICF-C793L
SPECIFICATIONS
ICF-C793/C793L
Photo: ICF-C793L
Ver 1.1 1999. 06
– 2 –
TABLE OF CONTENTS
1.
SERVICING NOTES
................................................
3
2.
GENERAL
...................................................................
4
3.
DISASSEMBLY
.........................................................
6
4.
ELECTRICAL ADJUSTMENTS
.........................
7
5.
DIAGRAMS
5-1. Block Diagram ................................................................
9
5-2. IC Pin Function Description ........................................... 11
5-3. Schematic Diagram ......................................................... 13
5-4. Printed Wiring Boards (SUFFIX-11) ............................. 15
5-5. Printed Wiring Boards (SUFFIX-12) ............................. 17
5-3. Schematic Diagram ......................................................... 13
5-4. Printed Wiring Boards (SUFFIX-11) ............................. 15
5-5. Printed Wiring Boards (SUFFIX-12) ............................. 17
6.
EXPLODED VIEWS
................................................ 19
7.
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.
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.
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.
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 microamperes).
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 microamperes).
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
– 3 –
CF2
CF3
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 CF2 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.
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.
SECTION 1
SERVICING NOTES
•
Discrimination of MAIN board
– MAIN BOARD (Component Side) –
1-671-839-11
or
1-671-839-12
– 4 –
SECTION 2
GENERAL
This section is extracted from
instruction manual.
instruction manual.
LOCATION OF CONTROLS