Samsung CS762ANT/SEHX User manual

COLOR
TELEVISION
RECEIVER
CHASSIS: SCT55A
MODEL: CS762ANT/SEHX
CS762ANT/POLX
S
FRVICE
Manual
i!
1. Precautions
exe) Mo) =u d=] @=AV/ 0-110) \\ ni) 0d a
2. Reference information
3. Specifications
4. Disassembly and Reassembly
ae
5.
Alignment
and
Adjustments
6. Troubleshooting
7. Exploded Views and Parts List
8. Electric Parts List
9. Block Diagrams
10. PCB Layout
11. Wiring Diagram
12. Schematic Diagrams

Precautions
a
1. Precautions
Follow
these
safety,
servicing
and
ESD
precautions
to
prevent
damage
and
protect
against
potential
hazards
such
as
electrical
shock
and
X-rays.
1-1
Safety
Precautions
1.
Be
sure
that
all
of
the
built-in
protective
devices
are
replaced.
Restore
any
missing
protective
shields.
2.
When
reinstalling
the
chassis
and
its
assemblies,
be
sure
to
restore
all
protective
devices,
including:
nonmetallic
control
knobs
and
compartment
covers.
3.
Make
sure
that
there
are
no
cabinet
openings
through
which
people--
particularly
children--might
insert
fingers
and
contact
dangerous
voltages.
Such
openings
include
the
spacing
between
the
picture
tube
and
the
cabinet
mask,
excessively
wide
cabinet
ventilation
slots,
and
improperly
fitted
back
covers.
If
the
measured
resistance
is
less
than
1.0
megohm
or
greater
than
5.2
megohms,
an
abnormality
exists
that
must
be
corrected
before
the
unit
is
returned
to
the
customer.
4.
Leakage
Current
Hot
Check
(Figure
1-1):
Warning:
Do
not
use
an
isolation
transformer
during
this
test.
Use
a
leakage-
current
tester
or
a
metering
system
that
complies
with
American
National
Standards
Institute
(ANSI
C101.1,
Leakage
Current
for
Appliances),
and
Underwriters
Laboratories
(UL
Publication
UL1410,
59.7).
5.
With
the
unit
completely
reassembled,
plug
the
AC
line
cord
directly
into
the
power
outlet.
With
the
unit's
AC
switch
first
in
the
ON
position
and
then
OFF,
measure
the
current
between
a
known
earth
ground
(metal
water
pipe,
conduit,
etc.)
and
all
exposed
metal
parts,
including:
antennas,
handle
brackets,
metal
cabinets,
screwheads
and
control
shafts.
The
current
measured
should
not
exceed
0.5
milliamp.
Reverse
the
power-plug
prongs
in
the
AC
outlet
and
repeat
the
test.
Fig. 1-1 AC Leakage Test
6. Antenna Cold Check:
With
the
unit's
AC
plug
disconnected
from
the
AC
source,
connect
an
electrical
jumper
across
the
two
AC
prongs.
Connect
one
lead
of
the
ohmmeter
to
an
AC
prong.
Connect
the
other
Jead
to
the
coaxial
connector.
. X-ray Limits:
The
picture
tube
is
especially
designed
to
prohibit
X-ray
emissions.
To
ensure
continued
X-ray
protection,
replace
the
picture
tube
only
with
one
that
is
the
same
type
as
the
original.
Carefully
reinstall
the
picture
tube
shields
and
mounting
hardware;
these
also
provide
X-ray
protection.
High Voltage Limits:
High voltage must be measured each time
servicing
is
done
on
the
B+,
horizontal
deflection
or
high
voltage
circuits.
Correct
operation
of
the
X-ray
protection
circuits
must
be
reconfirmed
whenever
they
are
serviced.
(X-ray
protection
circuits
also
may
be called "horizontal disable" or “hold-
down".)
Heed the high voltage limits. These include
the X-ray Protection Specifications Label, and
the
Product
Safety
and
X-ray
Warning
Note
on
the service data schematic.
OB
nS
8
a
See
Samsung Electronics
1-1

1-1 Safety Precautions (Continued)
9.
10.
11.
12.
13.
High voltage is maintained within specified
limits by close-tolerance, safety-related
components and adjustments. If the high
voltage exceeds the specified limits, check
each of the special components.
Design Alteration Warning:
Never alter or add to the mechanical or
electrical design of this unit. Example: Do
not add auxiliary audio or video
connectors. Such alterations might create
a safety hazard. Also, any design changes
or additions will void the manufacturer's
warranty.
Hot Chassis Warning:
Some TV receiver chassis are electrically
connected directly to one conductor of the
AC power cord. If an isolation transformer
is not used, these units may be safely
serviced only if the AC power plug is
inserted so that the chassis is connected to
the ground side of the AC source.
To confirm that the AC power plug is
inserted correctly, do the following: Using _
an AC voltmeter, measure the voltage
between the chassis and a known earth
ground. If the reading is gteater than 1.0V,
remove the AC power plug, reverse its
polarity and reinsert. Re-measure the
voltage between the chassis and ground.
Some TV chassis are designed to operate
with 85 volts AC between chassis and
ground, regardless of the AC plug polarity.
’ These units can be safely serviced only if
an isolation transformer inserted between
the receiver and the power source.
Some TV chassis have a secondary
ground system in addition to’ the main
. chassis ground. This secondary ground
14,
system is not isolated from the AC power
line. The two ground systems are
electrically separated by insulating
material that must not be defeated or
altered.
Components, parts and wiring that
appear to have overheated or that are
otherwise damaged should be replaced
with parts that meet the original
specifications. Always determine the
cause of damage or overheating, and
correct any potential hazards.
15.
16.
17.
18.
Observe the original lead dress,
especially near the following areas:
Antenna wiring, sharp edges, and
especially the AC and high voltage power
supplies. Always inspect for pinched,
out-of-pliace, or frayed wiring. Do not
change the spacing between components
and the printed circuit board. Check the
AC power cord for damage. Make sure
that leads and components do not touch
thermally hot parts.
Picture Tube Implosion Warning:
The picture tube in this receiver employs
"integral implosion" protection. To
ensure continued implosion protection,
make sure that the replacement picture
tube is the same as the original.
Do not remove, install or handle the
picture tube without first putting on
shatterproof goggles equipped with side
shields. Never handle the picture tube by
its neck. Some “in-line” picture tubes are
equipped with a permanently attached
deflection yoke; do not try to remove
such "permanently attached" yokes from
the picture tube.
Product Safety Notice:
Some electrical and mechanical parts
have special safety-related characteristics
which might not be obvious from visual
inspection. These safety features and the
protection they give might be lost if the
replacement component differs from the
original--even if the replacement is rated
for higher voltage, wattage, etc.
Components that are critical for safety are
indicated in the circuit diagram by
shading, (A\) or (A\).
Use replacement components that have ©
the same ratings, especially for flame
resistance and dielectric strength
specifications. A replacement part that
does not have the same safety
characteristics as the original might create
shock, fire or other hazards.
Samsung Electronics
1-2 Servicing Precautions
WARNING1:
First
read
the
“Safety
Precautions”
section
of
this
manual.
If
some
unforeseen
circumstance
creates
a
conflict
between
the
servicing
and
safety
precautions,
always
follow
the
safety
precautions.
WARNING2:
An
electrolytic
capacitor
installed
with
the
wrong
polarity
might
explode.
1.
Servicing
precautions
are
printed
on
the
cabinet.
Follow
them.
Always
unplug
the
unit's
AC
power
cord
from
the
AC
power
source
before
attempting
to:
(a)
Remove
or
reinstall
any
component
or
assembly,
(b)
Disconnect
an
electrical
plug
or
connector,
(c)
Connect
a
test
component
in
parallel
with
an
electrolytic
capacitor.
Some
components
are
raised
above
the
printed
circuit
board
for
safety.
An
insulation
tube
or
tape
is
sometimes
used.
The
internal
wiring
is
sometimes
clamped
to
prevent
contact
with
thermally
hot
components.
Reinstall
all
such
elements
to
their
original
position.
After servicing, always check that the
screws,
components
and
wiring
have
been
correctly
reinstalled.
Make
sure
that
the
portion around the serviced part has not
been damaged.
5.
Check
the
insulation
between
the
blades
of
the
AC
plug
and
accessible
conductive
parts
(examples:
metal
panels,
input
terminals
and
earphone
jacks).
Insulation
Checking
Procedure:
Disconnect
the
power
cord
from
the
AC
source
and
turn
the
power
switch
ON.
Connect
an
insulation
resistance
meter
(500V)
to
the
blades
of
the
AC
plug.
The insulation resistance between each
blade of the AC plug and accessible
conductive
parts
(see
above)
should
be
greater than 1 megohm.
.
Never
defeat
any
of
the
B+
voltage
interlocks.
Do
not
apply
AC
power
to
the
unit
(or
any
of
its
assemblies)
unless
all
solid-state
heat
sinks
are
correctly
installed.
Always
connect
a
test
instrument's
ground
lead
to
the
instrument
chassis
ground
before
connecting
the
positive
lead;
always
remove
the
instrument's
ground
lead
last.
1-3
Precautions
for
Electrostatically
Sensitive
Devices
(ESDs)
1.
|
Some semiconductor ("solid state") devices
are
easily
damaged
by
static
electricity.
Such
components
are
called
Electrostatically
Sensitive
Devices
(ESDs);
examples
include
integrated
circuits
and
some
field-effect
transistors.
The
following
techniques
will
reduce the occurrence of component
damage caused by static electricity.
Immediately before handling any
semiconductor
components
or
assemblies,
drain the electrostatic charge from your
body by touching a known earth ground.
Alternatively, wear a discharging
wrist-strap device. (Be sure to remove it
prior
to
applying
power--this
is
an
electric
shock precaution.)
After
removing
an
ESD-equipped
assembly,
place
it
on
a
conductive
surface
such
as
aluminum
foil
to
prevent
accumulation
of
electrostatic
charge.
Do
not
use
freon-propelled
chemicals.
These
can
generate
electrical
charges
that
damage
ESDs.
Samsung Electronics
5.
Use
only
a
grounded-tip
soldering
iron
when soldering or unsoldering ESDs.
6.
Use
only
an
anti-static
solder
removal
device.
Many
solder
removal
devices
are
not
rated
as
“anti-static”;
these
can
accumulate
sufficient
electrical
charge
to
damage
ESDs.
Do
not
remove
a
replacement
ESD
from
its
protective
package
until
you
are
ready
to
install
it.
Most
replacement
ESDs
are
packaged
with
leads
that
are
electrically
shorted
together
by
conductive
foam,
aluminum
foil
or
other
conductive
materials.
Immediately
before
removing
the
protective
material
from
the
leads
of
a
replacement
ESD,
touch
the
protective
material
to
the
chassis
or
circuit
assembly
into
which
the
device
will
be
installed.
Minimize body motions when handling
unpackaged replacement ESDs. Motions
such
as
brushing
clothes
together,
or
lifting
a
foot
from
a
carpeted
floor
can
generate
enough
static
electricity
to
damage
an
ESD.
1-3

Reference Information
a
MEMO
2.
Reference
Information
0
2-1
Tables
of
Abbreviations
and
Acronyms
Table 2-1 Abbreviations
Ampere
Megavolt
Ampere-hour
Megawatt
Angstrom
Megohm
Decibel
Meter
Decibel
Referenced
to
Microampere
One
Milliwatt
Microfarad
Degree
Celsius
Microhenry
Degree
Fahrenheit
Micrometer
degree
Kelvin
Microsecond
Farad
Microwatt
Gauss
Milliampere
Gigahertz
Milligram
Gram
Millihenry
.
v4
Henry
Milliliter
Hertz
Millimeter
Hour
Millisecond
Inches
Per
Second
Milfivolt
Kilowatt-hour
Nanofarad
Kilogram
Ohm
Kilohertz
Picofarad
Kilohm
Pound
Kilometer
Revolutions
Per
Minute
Kilometer
Per
Hour
Revolutions
Per
Second
Kilovolt
Second
(Time)
Kilovolt-ampere
Volt
Kilowatt
Volt-ampere
Liter
Watt
Megahertz Watt-hour
22a222ERR ERE S
Be az
<o 83a
a
Samsung
Electronics
I
Samsung
Electronics
2-1

Reference information
Table 2-2 Table of Acronyms
ABL
ACC
AF
AFC
AFT
AGC
AM
ANS!
APC
APC
AVC
BAL
BPF
B-Y
CATV
ecb
CCTV
Ch
CRT
Cw
bc
EIA
ESD
ESO
FBP
FBT
FM
GNO
G-Y
HF
HI-FI
Ic
Ic
IF
Automatic Brightness Limiter
Alternating Current
Automatic Chroma Control
Audio Frequency
Automatic Frequency Contro!
Automatic Fine Tuning
Automatic Gain Control
Amplitude Modulation
American Nationa! Standards Institute
Automatic Phase Control
Automatic Picture Control
Audio-Video
Automatic Volume Control
Balance
Bandpass Filter
Blue-Y
Community Antenna Television (Cable TV)
Citizens Band
Charge Coupled Device
Closed Circuit Television
Channel
Cathode Ray Tube
Continuous Wave
Direct Current
Digital Volt Meter
Electronics Industries Association
Electrostatic Discharge
Electrostatically Sensitive Device
Feedback Pulse
Flyback Transformer
Flip-Flop
Frequency Modulation
Fail Safe
Ground
Green-Y
High
High-Frequency
High Fidelity
Inductance-Capacitance
Integrated Circuit
Intermediate Frequency
i/0
L
L
LED
LF
MOSFET
MTS
NAB
NEC
NTSC
oso
PCB
PLL
PWM
QiF
R
RC
RF
RY
SAP
SAW
SIF
SMPS
S/N
sw
TP
™
wv
UHF
UL
Uv
vcD
vco
VCXO
input/output
Left
Low
Light Emitting Diode
Low Frequency
Metal-Oxide-Semiconductor-Field-Effect-Tr
Multi-channel Television Sound
National Association of Broadcasters
National Electric Code
National Television Systems Committee
On Screen Display
Printed Circuit Board
Phase-Locked Loop
Pulse Width Modulation
Quadrature Intermediate Frequency
Right
Resistor & Capacitor
Radio Frequency
Red-Y
Second Audio Program
Surface Acoustic WavelFilter)
Sound Intermediate Frequency
Switching Mode Power Supply
Signal/Noise
Switch
Test Point
Transistor Transistor Logic
Television
Ultra High Frequency
Underwriters Laboratories
Ultraviolet
Variable-Capacitance Diode
Voltage Controlled Oscillator
Voltage Controlled Crystal Oscillator
Very High Frequency
Video Intermediate Frequency
Variable Resistor
Video Tape Recorder
Vacuum Tube Voltmeter
Transistor .
Samsung Electronics
2-21C Line Up
atch
A
UT
see
IF processing
200
SOTieS
o..ceessscseeeccsecesncesstsssecsvecsnnecasessnecnsensuacuncasesnecsusssnsenscnscnanecanecnsatacserensseneegnensseneeere
Video,
Chroma
Processing
300
Series
oc
esssescsesssscssssecsseccacscesscarecuvecuecsscasessseesneceseeaequnssneceanssessaneensgnuenansnseansnnssessstnenseeseseneenee
ges
Vertical
Deflection
RV,CV,LV,QV
..»
V/M
Section
RCI
OJAI
cesscecsesscesccssssssssessesscsenseutsussstmnnersnssseseecnecennncennennnnsensansanssnssssssseenennassneeeeeeenseeen
eee
eeeae
ee
NICAM
Section
RP,CP,LP,XP,ICP
RC,CC,DZC,QC
COMB
Filter
Section
RP,PD
cessccosscccnessssuseccesnscssnscccnvesonvessnesseneccenscesaseecusceavecsnecsscsanrecsussennsaunscanscnsssenncconecnasscanaseenseeses
POWER-S/W
Section
a
Samsung
Electronics
2.3