Samsung SC-452 User manual

II
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14”
COLOR
MONITOR
SAMSUNG
SERVICE
MANUAL
Electron
Devices
80-452
SPECIFICATIIONir-I'
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tube
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Dimension--------.-
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TABLE
OF
CONTENTS
SECTION
I
GENERAL
INFORMATIONS
[1]
SAFETY
PRECAUTION
........................................................................................
3
[2)
DOCUMENT
DESCRIPTION
..........
’
.....
”L
__________________________________________________________________
4
[3]
PRODUCT
DESCRIPTION
.......................
-
_____________________________________________________________
4
[41
OPERATING
INSTRUCTION
..................................................................................
5
[5]
ELECTRICAL
CHARACTERISTIC
_____________________________________________________________________________
5
[6]
MECHANICAL
CHARACTERISTIC
___________________________________________________________________________
5
[7]
DISPLAY
CHARACTERISTIC
.................................................................................
5
[8]
CPT
CHARACTERISTIC
......................................................................................
5
{9]
ENVIRONMENTAL
SPECIFICATION
.........................................................................
5
[10]
WEIGHT
......................................................................................................
5
SECTION
II
SERVICE
INFORMATION
(1)
ADJUSTMENT
...............................
'
..............................................................
7—8
[2]
TROUBLE
SHOOTING
...................................................................................
9#12
('3)
SERVICE
NOTE----‘
...............................
-_
.....................................................
13-14
[4)
BLOCK
DIAGRAM---"
...................................................................................
15-17
[5)
THEORY
OF
OPERA.TION_--_-;
......................
.
........................................................
18
SECTION
III
FIGURES
'
(13
TIMING
CHART
....................................
.....................................................
20
[21
ADJUST
AND
CONNECTORS
FOR
PCB
..........
'
.......
_-;
.......................
_
.........................
21
[33
.MAINPC
BOARD
ASS’Y
DIMENSIONS---_-_-----____--;
................
'
______________________________
._-__22
'
(.4);
MECHANICAL
DIMENSIONS
FOR
CPT
................
____________________________________________
23:24
(5]
'
SCHEMATIC
AND
VOLTAGE
WAVE
FORM
_______________________________________________________________
25
[6]
P03
COMPONENT
LOCATION
.....................
‘
.................
.
...................................
26*28
.
SECTION
IV
ATTACHMENTS
I
_[11EXPLODED
VIEw
................................
_
............................................................
30
-
£2)
PARTS
LIST
...........................................
I
.......
;
..........................................
31—37
MEMQ:—_—_-—;§——_.
...........
.................................................................
38
'HEAD
OFFICE
&.
OVERSEAS
BRANCH
OFFICES
-----------
'
-------------------------------------------------------
_-__
-----------------
39

SECTION
I
GENERAL
INFORMATION
[1]
SAFETY
PRECAUTION
WARNING:
Service
should
not
be
attempted
anyone
unfamiliar
with
the
necessary
precautions
on
this
unit.
The
following
precautions
are
necessary
during
servicing.
1.
Some
parts
such
as
a
picture
tube
in
this
unit
have
special
safety-related
charaeristics
for
X-RAY
RADIATION
protection.
For
continued
safety,
the
parts
replacement
should
be
undertaken
referring
to
item
2
below.
.
Many
electical
mechanical
parts
in
this
unit
have
special
safety-related
characteristics
for
protection
against
shock
hazard
and
others.
These
characteristics
are
often
passed
unnoticed
by
a
visual
inspection
and
the
protection
afforded
by
them
cannot
necessarily
be
obtained
by
using
replacement
components
rated
for
higher
voltage
wattage,
etc.
Replacement
parts
which
have
these
special
characteristics
are
identified
in
the
manual
and
supplements
by
shading
on
the
schematic
diagram
and
the
parts
list.
Before
replacing
of
these
components
read
the
parts
list
in
this
manual,
carefully.
.
When
replacing
chassis
in
the
cabinet,
always
be
certain
that
all
the
protective
devices
are
installed
properly,
such
as
insulating
covers,
strain
relief,
etc.
.
Before
replacing
the
back
cover
of
the
set,
thoroughly
inspect
inside
the
cabinet
to
see
that
no
stray
parts
or
tools
have
been
left
inside.
.
Before
returning
the
set
to
the
customer
always
perform
an
Ac
leakage
current
check
on
the
exposed
metallic
parts
of
the
cabinet,
such
as
terminal,
screwheads,
metal
overlays,
control
shafts,
etc.
To
be
sure
the
set
is
safe
to
operate
without
danger
of
electrical
shock.
Plug
the
AC
line
cord
directly
into
a
120V
AC
outlet
(do
not
use
a
line
isolation
transformer
during
this
check).
Use
an
AC
voltmeter
having
5000
ohms
per
volt
or
more
sensitivity
in
the
following
manner.
Connect
a
1500
ohm,
10
watt
resistor,
paralleled
by
a
0.15mfd(,u
F),
250V
AC
capacitor,
between
a
known
good
earth
ground
(water
pipe,
conduit,
etc.)
and
the
exposed
metallic
parts,
one
at
a
time.
Measure
the
Ac
voltage
across
the
combination
of
1500
ohm
resistor
and
0.15
mfd(p
F)
capacitor.
Reverse
the
AC
plug
at
the
AC
outlet
and
repeat
AC
voltage
measurements
for
each
exposed
metailic
part.
Voltage
measured
must
not
exceed
0.3V
RMS.
This
corresponds
to
0.2mA
AC
any
value
exceeding
this
limit
constitutes
a
potential
shock
hazard
and
must
be
corrected
immediately.
(50000hmper
volt
or
more
Sensitivity)
'
Reading
”Should
not
exceed
0.3V.
Place
this
probe
on
each
-
exposed
metallic
part.
.
voltmeter
Heck-up
for
Leakage
Current-Check.
02'5“)“
.2_50YA07=
Good
earth
ground
such
as
a
water
pipe,
conduit
etc.

TTL
Drive
mode
in
put
a
highlight
of
these
is
provided
[2]
DOCUMENT
DESCRIPTION
below.
0
Resolution
:
480
dots
(H)><200
line
This
is
technical
Specification
for
a
80-452
Color
(V)
display
monitor.
0
Display
capability
:
2000
Characters
(80X
This
document
contains
information
on
all
technical
25)
details
Of
the
monitor.
‘
Active
display
area
:
Horizontal~252mmi
4mm Vertical 174mmfh
[3]
PRODUCTION
DESCRIPTION
4mm
Horizontal
frequency
:
15.75KH2
Vertical
frequency
:
6OHz/50Hz
This
SC-452
Color
diSplay
monitor
to
be
Operated
in
USING
SC—452
COLOR
DISPLAY
MONITOR
Meeting
80452,
Color
display
monitor.
Refer
to
the
diagram
below
to
be
sure
that
your
SC-452,
package
includes
all
the
items
in
this
picture.
Save
the
original
box
and
packing
materials
in
case
you
have
to
ship
or
transport
80-452.
@ @
(D
®
@
6)
Color
display
monitor
(SC-452)
(2)
Power
cord
(3)
Signal
cable:
Connects
IBM
PC
or
Compacibles
@
User's
manual
®
Swivel/Tilt
stand:
Enables
you
to
position
SC-452
at
the
best
angle
and
tilt
for
easy
viewing.
‘

£4]
OPERATING
INSTRUCTION
1.
External
instruction
>1:
Front
Power
switch
contrast,
brightness,
green
switch
(option)
>1:
Rear
Horizontal
hOld,
vertical
hold,
vertical
size
2.
Service
instruction
(internal
controls)
Supply
voltage,
sub
brightness,
Horizontal
center,
vertical
center,
brown
color
controls.
[5]
ELECTRICAL
CHARACTERISTICS
1.
AC
Power
input
AC
115V:15%,
60Hz
AC
220~240V,
50Hz
(Optional)
Power
consumption
is
70W
under
nomal
viewing
condition
and
be
used
internal
fuse
protection.
2.
Video
input
Video
:
RG81
TTL
Level,
Positive
Sync
:
TTL
Level,
Positive
Band
width
:
15MHz
(-3dB)
3.
Horizontal
electronics
Frequency
Retrace
time
4.
Vertical
electronics
Frequency
Retrace
time
:
15.2KH2~16.3KHZ
:
11.1608
:
47Hz~63Hz
:
9.55uS
[6]
MECHANICAL
SPECIFICATION
Figure—Shows
the
mechanical
specification
for
the
CPT
display
monitor.
[7]
DISPLAY
CHARACTERISTICS
1.
Display
size
:
H;
252i4mm
V;
147i4mm
: 5
><7dot
matrix
Character
pattern
2000
Characters,
80
X
24
lines.
2.
Display
capability
[8]
CPT
CHARACTERISTICS
1.
Type
:14”
in-line
GUN
(37JGG68X)
90
degree
deflection
angle
2.
Phosphor
:
P22
C.l.E
Cordinates
3.
Neck
diameter
:
29.1q6
4.
Phosphor
dot
pitch
:
0.52mm
Maximum
5.
Implosion
protection
to
be
approved
by
UL
and
C.
SA
6.
Degaussing
:
Automatic
degaussing
shall
be
provided
>1:
Deflection
yoke
and
neck
components
are
preset
in
CPT
factory,
SO
there
is
no
need
for
purity
adjustment.
[9]
ENVIRONMENTAL
SPECIFICATION
1.
Operating
temperature:
5°C
to
40°C
Centigradein
side
enclosure
:
20%
to
80%
Enclosure
convection
cooled
(non
condensing)
:
-20°C
to
60°C
out
Side
enclosure
2.
Relative
humidity
3.
Temperature
storage
[I0]
WEIGHT
Weight:
13.5kg

SECTION
II
SERVICE
INFORMATION
:1:
Control
and
terminal
identification
[Important
notice
for
service
personel
before
servicing]
PLEASE
READ
BEFORE
ATTEMPTING
SERVICE
@
Line
voltage
must
be
kept
with
in
:15%
of
the
rated
voltage.
®
Do
not
discharge
ARC
or
measure
high
voltage
when
high
voltage
lead
is
connected
to
CPT.
Discharge
2ND
anode
of
OPT
only
after
high
voltage
lead
has
been
disconnected.
Do
not
discharge
high
voltage
lead
at
any
time,
damage
to
transistors
may
result.
(3)
While
the
monitor
is
in
operation,
do
not
attempt
to
connect
or
disconnect
any
wires.
GD
Disconnect
all
power
before
attmepting
any
repairs.
69
When
the
power
is
on
do
not
attempt
to
short
any
portion
of
the
circuit.
This
shorting
may
cause
demage
to
the
transistor
in
receiver.
,

[I]
ADJUSTMENT
Apply
power
and
TTL
video"3ignal
to
the
data
display
l.
ADJUSTING
THE
FRONT
CONTROLS
FRONT
VIEW
WT"
L
V
J
L
1
\
Riffs—.7
//
SIT)
3.
Contrast
45-1.
On—Olf
Siw
\\
~4.
Brightness
2
Power
indicator-~53
(D
Power
switch
2)
The
maxium
brightness
(fully
clock
wise)
level
USGd
t0
PUSh
the
power
on
0"
Off-
shall
be
limited
with
the
internal
sub
brightness
When
the
power
is
on
the
power
indicator
(LED)
is
factory
adjustment.
lit.
3)
Control
shall
adjust
the
ground
raster
to
the
®
Bright
control
point
of
extinction.
1)
The
brightness
control
knob
shall
provide
the
@
Contrast
control
customer
With
means
for
adjusting
the
display
Adjusts
the
display
to
the
contrast
preferred
by
the
intensity off set level as viewing conditions
user.
vary.
2.
ADJUSTlNG
THE
REAR
CONTROLS
QQQQQQ
,
f ,
ZV-Size
ZV-Hold
K-—H-Hold
[SELECTOR
SKW
-—-~Signal
input
Power
input

®
H-Hold
control
Adjusts
the
horizontal
stability
of
the
display.
®
V-Hold
control
Adjusts
the
vertical
stability
of
the
display.
C3) V-Size control
Turn
this
knob
for
the
proper
vertical
size
of
the
display.
Turn
the
knob
clock
wise
for
a
larger
‘
display,
turn
it
counter
clock
wise
for
a
smaller
display.
@
Selector
switch
(H-center
switch)
If
you
are
using
the
monitor
with
the
APPLE
compatible,
the
SEW
501,
should
be
to
the
right
side.
If
you
are
using
the
monitor
with
the
IBM
compatibe,
the
SW
501,
should
be
to
the
left
side.
3.
ADJUSTING
THE
INTERNAL
CONTROLS
HORIZONTAL
ADJUSTMENT
(D
Received
the
cross
hatch
pattern.
®
Turn
VR
502
and
adjust
it
until
synchronization
is
secured.
(3)
Signal
and
turn
the
power
switch
ONIOFF
and
this
confirm
the
stability
of
sync.
G1)
If
picture
positions
is
left
or
right
at
center
of
CPT
face,
adjust
the
H-shift
of
VR501
properly.
VERTICAL
ADJUSTMENT
Q
Received
the
cross
hatch
pattern.
(9
Turn
VR401,
and
adjust
it
until
sync
secured.
(3)
The
pattern
position
is
up
or
down
at
the
center
of
CPT
face
by
adjust
the
V-shift
of
VR452
properly.
FOCUS
ADJUSTMENT
(D
Received
the
bull's
eye
(@)
pattern.
(2)
Adjust
the
brightness
V/‘R
control
for
generally
bright.
(3)
Adjust
the
focus
WR
control
for
best
condition.
COLOR
PURITY
ADJUSTMENT
@
Operate
the
receiver
for
15Min.
With
brightness
control
at
maximum
to
warm
up
the
CPT.
(2)
Degauss
the
receiver
fully
by
using
an
external
degaussing
coil.
(3)
Roughly
adjust
convergency.
@
Receive
a
black
and
white
signal.
69
Turn
red
and
blue
low
light
controls
fully
counter
clock
wise,
if
green
field.
Adjust
drive
controls,
if
green
field
is
not
obtained.
©
Loosen
the
deflection
yoke
clamp
screw,
and
move
.the
DY
to
the
purity
magnet
as
close
as
possible.
®
‘Loosen
purity
magnet
clamper
and
adjust
the
purity
magnet
to
set
the
vertical
green
raster
precisely
as
the
center
of
screen,
then
tighten
the
clamper.
C8)
Slowly
move
the
deflection
yoke
forward
and
adjust
for
the
best
overall
green
screen.
(9)
Tighten
the
deflection
yoke
clamp
screw.
(9
Produce
the
blue
and
raster
by
low.
Light
controls
and
observe
that
good
purity
is
obtained
on
the
respective
field.
®
Observe
that
uniform
white
raster
is
obtained
by
adjusting
R.G.B
low
light
controls.
It
screen
is
not
uniformly
white,
repeat
above
procedure.
WHITE
BALANCE
ADJUSTMENT
®
Turn
in
a
black
and
white
program.
(2)
Turn
the
brightness
controller
fully
counter
clock
wise
and
adjust
VR351.352.353.354.355
in
the
mechenical
center.
(3)
Slowly
turn
the
screen
control
clock
wise
from
the
full
counter
clock
wise
position,
until
two
colors
out
of
three
R.G.B
appear
horizontal
on
the
picture
tube.
@
Extinguish
the
two
horizontal
all
colors
on
the
picture
tube
by
turning
the
two
repective
low
light
controls
fully.
counter
clock
wise.
6)
Turn
the
screen
control
further
clock
wise
until
the
three
color
appears
as
a
faint
horizontal
line
on
the
picture tube.
©
Make
the
horizontal
line
white
by
turning
the
two
low
light
controls
white
were
previously
set
fully
counter
clock
wise
as
step
3.
®
Alternately
adjust
the
red
blue
drive
controls
to
produce
a
normal
black
and
white
picture,
check
the
black
and
white
picture
detail
proper
black
and
white
condition
(no
coloration)
form
low
lights
to
highlights
at
all
brightness
level
for
proper
tracking.
Proper
tracking
at
all
brightness
levels
can
be
obtained
when
the
controls,
low
light
controls,
and
drive
controls
are
properly
adjust,
if
the
results
are
unset
is
factory,
repeat
all
the
above
steps.
CONVERGENCE
ADJUSTMENT
>l<
Note;
Before
adjusting
covergence,
vertical
size,
linearity
and
focus
adjustment
must
be
completed.
@
Received
the
cross
pattern.
(2)
The
brightness
level
should
be
on
higher
than
necessary
to
obtain
a
clear
pattern.
®
Loosen
the
convergence
magnet
clamp
and
converge
the
red
and
bl'ue
at
the
center
of
the
screen,
by
rotating
the
RB
static
convergence
magnet.
@
Alight
the
converged
red/blue
dots
wite
the
green
static
convergence
magnet.
©
Tighten
the
convergence
magnet
clamp.
09
Remove
the
DY
wedges,
and
slightly
tilt
the
DY
for
horizontal
and
vertical
to
obtain
good
overall
convergence.
®
Secure
the
deflection
by
inserting
the
wedge.
If
purity
error
is
found,
repeat
the
purity
_.
adjustment.
”5*.
.

[2]
TROUBLE
SHOOTING
-|.
TROUBLE
SHOOTING
INFORMATION
CHART
>i<
INTRODUCTION
This
is
the
trouble
shooting
section.
It
consists
of
a
symptom
chart,
showing
the
symptom
and
an
action
to
be
taken
to
rectify
the
problem.
The
best
way
to
use
this
section
is;
(D
Look
on
the
chart
to
find
the
symptom
that
matches
what
the
defective
monitor
is
doing
C2) Try the recommended action.
CD NO RASTER
Check
AC
voltage
between
terminal
“L”
and
”N”
on
SMPS
board
(PCB:
17-01—028)
AC
voltage
is
normal
115V
AC
voltage
is
on
-
Failure
of
AC
cap
plug
~
Power
cord
open
Check
fuse
F601
(3A)
-
Failure
of
switch
(SW601)
-
Failure
of
fuse
Connected
Disconnected
(:>
Check
Check
8+
between
0506
and
GND
(103V
DC)
I
I
I
I
l
I
B+Line
ok
Abnomal
B+Line
If:
Normal
- H-out
put transistor
(Q552)
-
Shorted:
Failure
of
H~output
transistor
-Failure
of
B+(103V)
power
regulator
circuit
-
103V
DC
Line
shorted
Check
B+(24V
DC)
between
D452
“K"
and
GND
-Fai|ure
of
H-OSC
I
circuit
I
I
0K
Abnormal
24Vline
-w
-
240V
DC
Line
shorted
-Fai|ure
of
H-Drive
-
Failure
of
H-drive
circuit
circuit
-Failure
0f
«
Failure
of
F.B.T
B'H24V)
ROW?
-Fai|ure
of
high
voltage
This
condition
regmator
C'rcwt
prOteCtiO”
Circu”
-
Failure
of
R557
R558
is
-Fai|ure
of
multifailure
ambient
FBT
circuit

i2}
B
i
(115V)
NORMAL,
NO
RASTER
Check
CPT
heater
Lighted
Check
CPT
cathode
voltage
High
Normal
NO
CPT
heater
disconnected
Failure
of
heater
circuit
Failure
of
FBT
Check
emitter
of
TR
0351~Q353
Check
screen
voltage
Low
Normal
Failure
of
TR
(0351
~Q353)
and
associated
circuit
on
socket
board
Failure
of
TR
(Q301-Q304)
a
nd
associated
circuit
-Fai|ure
of
OPT
G2
circuit
-
Failure
of
OPT
{3)
ABNORMAL
BRIGHTNESS
OF
SCREEN
Nomal
—--
Abnomal
Failure
of
CRT
G2
circuit
This
condition
is
,
-Failure
of
OPT
multifailure
Check
12
voltage
line
Low
Normal
Does
R408,
409
open
failure
of
12V
Line
circuit
Failure
of
Q401,
402
Check
emitter
of
TR
Q351,352,353
Low
Normal
Failure
of
video
circuit
.
Failure
of
TR
Q401,
402,
351,
352,
353
-
Failure
of
associated
circuit

@
NOMAL
RASTER,
PICTURE
ABNOMAL
>i< NOTE: Apply positive signal as input
for R881 TTL
Check video process circuit
TR
Q
301,
IC 301, 302, 303, 304, 305
302,
303,
304,
305,
351,
352,
353
(5) NO VERTICAL SWEEP
Check
B+(24V)
Voltage
on
FBT
circuit
Low
voltage
or
over
voltage
condition
Apply
ii
14pin
sync
signal
to
Ii
llpin
of
l0501
Failure
of
24V
rectifier
circuit
Without effect
Vertical height
©
FAILURE
OF
WHITE
BALANCE
Failure of lCSOl
.
Failure
of
IC501
Failure of DY
Re-adjust
white
balance
OK
+
Good
ON
Check
CPT
cathode
voltage
Abnormal
Normal
-Fai|ure of video output
Tr 0351, 352,
353
-Failure
of
video
output
TR
associated
circuit
‘
Failure
of
OPT
Failure
of
video
circuit
Al

®
UNSTABLE
VERTICAL
Check
frequency
variation
with
rotating
V-HOLD
60Hz
appears
but
unstableness
’4
Failure
of
IC
401
-—-—.—-
Oscillation
frequency
shift
Failure
of
lC40l,
501
Failure
of
|C401,
501
associated
circuit
UNSTABLE
HORIZONTAL
Check
frequency
variation
with
rotating
H-HOLD
Lock
of
horizontal
sync
Failure
of
ICSOl
-——*—
Oscillation
frequency
shifts
Failure
of
10501
Failure
of
|0501
associated
circuit

2.
TROUBLE
SHOOTING
FOR
RESPECTIVE
SYMPTOMS
2.!
NO
RASTER
(I)
Turn
the
brightness
control
clockwise
fully.
If
raster
does
not
apper,
check
up
next
item.
® Check CPT heater
it
is
not
on;
CPT
heater
disconnect
&
failure
heater of FBT
OK;
Proceed
to
next
check
item
(3)
Check
high
voltage
by
HV
voltage
meter
High
voltage
is
not
obtained
;
Check
of
FBT
(T501)
Check
of
Q552
Collector
Check of Q552 Base
Check of HDT
Check
of
pin4
lC501
Check of pin3 of |C501
OK
;
Proceed
to
next
check
item
GD
Check
CPT
electrode
voltage
as
follow.
G2
;
300i50V
G4
;
6Ki500V
G1 ; 0V
K
;
180:10V
Voltage
of
G2
and
G4
are
not
obtained;
check
of
T501.
Voltage
of
K
is
not
obtained;
Check
of
video
amp.
and
ambient
circuit.
Voltage
of
G2,G4,G1
and
K
are
normal;
CPT
is
faulty.
OK
;
Proceed
to
next
check
item.
(5)
Check
AC
voltage
at
AC
input
point
on
SMPS
AC
voltage
abnormal;
Failure
of
A0
line
OK
;
Proceed
to
text
check
item
©
Check
fuse
F601
Disconnected;
Failure
of
switching
power
transformer.
Failure
of
bridge
diode
Failure
of
degaussing
circuit
0K
;
Proceed
to
next
check
item
Q)
Check
DC
output
voltage
Abonormal;
Failure
of
|C60l
and
ambient
circuit.
OK
;
Proceed
to
next
check
item.
2.2
ONLY
ONE
RASTER
LINE
APPEARS
IN
HORIZONTAL
DIRECTION.
®
Check
of
deflectin
yoke
vertical
coil;
Vertical
coil
open
and
shorted.
C2)
Check
of
pin
7
of
l0501
when
voltage
is
not
obtained;
Check
of
0451
®
Check
of
pin
2
of
IC
401
2.3
UNSTABLE
VERTICAL
6)
Check
frequency
varition
with
rotating
V-Hold.
®
Check
of
pin
7,
8,
9
of
lC501.
2.4
UNSTABLE
HORIZONTAL
CD
Check
of
frequency
variation
with
rotating
H-Hold.
®
Check
of
pin
3
of
lC501.
2.5
NO
PICTURE
The
nearly
square
pulses
output
of
the
oscillator
applies
it
the
base
of
Q551
to
switch
on
and
off
this
transistor,
there
by
passing
pulse
current
through
the
primary
side
transformer
(HDT).
With
each
turning
on
and
off
of
the
transistor
spiking
occur
because
of
inductance.
The
horizontal
out
put
transistor
Q552
is
simply
a
switch
which
is
truned
on
and
off
at
the
horizontal
scan
rate
by
the
drivcing
signal
applied
to
its
base,
a
sawtooth
current
through
the
deflection
coil
is
required
to
sweep
the
beam
linearly
across
the
CPT
screen.
This
happen
when
Q552
is
turned
on
and
its
collector
voltage
droops
to
near
zero,
and
the
0556
begins
discharging
through
the
deflection
coil
which
deflect
the
beam
to
the
reigh
edge
of
the
CPT.
At
that
time,
Q552
cuts
off
and
0556
ceases
to
supply
current
to
the
deflection
coil.
However,
an
induced
voltage
appear
across
the
deflection
yoke
coil
as
the
magnetic
field
collapes
and
an
oscillation
then
occurs
the
deflection
coils
and
0556.
During
the
first
half
cycle
of
this
oscillation,
the
induced
voltage
is
felt
across
the
collector
of
Q552
with
cut
off
0556
and
the
primary
T501.
This
voltage
is
stepped
up
T501
rectified
to
produce
high
voltage
that
is
applied
to
anode
of
the
CPT.
[3JSERVICE
NOTE
Servicing
precautions
The
following
precautions
should
be
observed
when
service is required.
1.
Replacment
parts
which
have
special
safety
characteristics
are
identified
by
shading
on
the
schematics.
Replace
these
critical
components
with
recommended
replacement
parts.
Don’t
degrade
the
safety
of
the
set
through
improper
servicing.
2.
Comply
with
all
cautions
and
safety-related
notes
on
or
inside
the
monitor
cabinet,
on
the
monitor
chassis
or
on
the
picture
tube.
3.
Maintain
correct
lead
dress
and
part
placement.
Extra
caution
should
be
taken
to
assure
proper
dress
in
the
high
voltage
circuit
area.
Where
a
malefaction
has
occured,
those
components
or
circuits
that
indicate
evidence
of
abnormality
should
be
replaced
or
corrected.
Always
use
the
manufacturer’s
safety
specified
replacment
components.

4.
When
replace
a
chassis
in
the
cabinet,
always
make
certain
that
all
the
protective
devices
are
back
in
thier
proper
place,
such
as:
non
metallic
control
knobs,
insulating
fishpapers,
component
cover/shields,
isolation
resister
capacitor
networks
etc.
.
Before
returning
the
monitor
to
the
owner,
be
sure‘
that
no
protective
device
built
into
the
set
by
the
manufacturer
has
become
defective,
or
inadvertently
defeated
during
servicing.
Therefore,
the
following
checks
are
recommended
for
the
continued
protection
of
the
cutomer
and
service
engineer.
LEAKAGE
CURRENT
HOT
CHECK
Plug
the
AC
line
cord
directly
into
a
115V
AC
outlet
(do
not
use
an
isolation
transformer
in
this
check)
Use
a
leakage
current
tester
which
complies
with
American
National
Standars
Institute
(ANSl
0101.1-1971,
LEAKAGE
FOR
APPLIANCE),
and
UNDERWRITERS
LABORATORIES
(UL,
1410).
Meaure
current
form
all
the
exposed
metal
parts
of
the
cabinet,
(screwheads,
metal
overlays,
etc.)
to
earth
ground,
particularly
any
exposed
metal
part
having
a
return
path
to
the
chassis.
The
test
should
be
conducted
with
AC
switch
“ON"
and
then
repeated
with
“OFF".
Any
current
measured
must
not
exceed
O.5mA
with
to
AC
line
cord
inserted
in
the
AC
supply
circuit
receptacle.
Any
measurement
not
within
the
limits
outlined
above
are
indicative
of
a
potential
shock
hazard
and
corrective
action
must
be
taken
before
returning
the
set
to
the
customer.
.
X-RADIATION
PRECAUTION
This
product
contains
critical
electrical
and
mechanical
parts
essential
for
X-RAY
protection,
see
CRITICAL
COMPONENT
LIST
and
other
service
adjustment.
Anode
voltage
normal
is
22.8KV
at
115V
line
and
must
not
exceed
28KV
under
any
operating
condition.
To
measure
anode
voltage,
set
brightness
for
a
very
dim
picture.
Use
a
high-voltage
meter
between
the
chassis
and
the
anode
lead
to
measure
HV.
If
high
voltage
exceeds
the
specified
limits,
check
each
components
on
the
chassis
and
take
necessary
corrective
action.
.
Do
not
remove,
install
or
handle
the
picture
tube
in
any
manner
unless
shatter-proof
goggles
are
worn.
People
not
so
equipped
should
be
kept
away
while
a
picture
tube
is
handled.
Keep
the
picture
tube
away
from
body
while
handhng.

[4]
BLOCK
DIAGRAM
T
COLOR
MATRIX
CIRCUIT
|0301~305
VIDEO
DRIVER
CIRCUIT
“ VIDEO AMP. OUTPUT CIRCUIT
II
r
h...
r'
TR
Q301~
303
TR
Q351~353
LEI—II
VIDEO
PROCESS
CIRCUIT
SYNC
SYNC
PROCESS
(H-OSC,
+—
RECEIVER
V-OSC
V-DRIVER,
AFC)
ICSOl
DC
OUTPUT
103V
5V
H H
IA
,5
BLANKING
*
VERTICAL
OUTPUT
CLIP
ED
I I
VERTICAL
PUMP-UP
IC401
II
V-DY
S/W
TR
TRANS
REGULATOR
I.C
RECTIFIRE
HORIZONTAL
DRIVER
CIRCUIT
TR
Q551
~—-—-—->~—
OUTPUT
TR
Q552’
1
H-DY
HIGH
VOLTAGE
CIRCUIT
HORIZONTAL
AMP.
FBT
T501
LINE
FILTER
AC
INPUT
I
II

COMPONENT
POWER
DISSIPATION
l.|C
Test
Data
No.
Circuit
No
Description
Function
Vi
‘
V0
lo
Ptot
Remark
|0306
L78050V
5V
REG.
9.3V
4.99V
678mA
0.29W
l0502
L78812CV
12V
REG.
14.9V
12.02V-
-_
. .
0.14A
0.4W
'
|C301
74LSO4
TTL
4.99V
_3L2mA
74L806
TTL
4.99V
'3L7mA
|C303
74L826
TTL
4.99V
4.4mA
1
2
3
4
|C302
5
6
|C305
74L811
TTL
4.99V
6.6mA
No
Circuit
No
Description
function
Test
Data
Remark
Ver.
/
Hor
Iccl6
|o4
Pd
V13
V16
Process
Circuit
12.02V 12.65V
1
lC501
LA7823
128mA
7.8mA
2.13W
Vertical
V6
V3
|12
Pd
2
|C401
LA7830
Pumpup
Process
24.3V
26.6V
0.66A
2.13W
2.
TRANSISTOR
Test
Data
No.
Circuit
No
Description
Function
Vcno
[V]
ICEmA]
PcEmW]
Remark
Video
Driver
0301
~Q303
25C1815
H
17.36
16.34
154.9
0304
”'
Contrast
15.54
_ _
32.70
159.6
Q305
”
Circuit
16.60
8.60
.
86.89
0401,402
”
Blanking
8.42
1.82
15.35
Clip
0403
2SA1015
Circuit
8.57
52.76
201.54
0351
2SC1507
Video
Amp
171.9
189
756
0352
”
”
171.8
187
748
0353
”'
”
171.2
186
744
QW‘QG‘lU'Ih-UJN
0551
”
H-Driver
167.0
99.40
346
I—‘
C)
Q552
2801397
H-Output
880--
.
2.72
21.7ow

SEMICONDUCTORS
BASING
74LSO4
O6
11
26
LA7823
TRANSISTOR
I
1.
EMITTER
2.
COLLECTOR
3.
BASE
I
III
w
2SC1815
2SC1015
if)
Q)
DIODE
K:
KATHODE
A:
ANODE
fit
[/71
123
L
REGULATORIC
LA7805
LA7812
PIN
1.
COMMON
2.
INPUT
3. OUTPUT
TDA
4601
L
BASE
2. COLLECTOR (HEAT SINK)
3. EMITTER
28C
1507
%#—%fi
{—
.5"
K
A

[Si
THEARY
OF
OPERATION
(CIRCUIT
DESCRIPTION)
I.
General
This
monitor
contains
two
idependent
circuits.
This
first
is
the
power
supply
section,
and
the
second
is
the
sweep
or
CPT
drive
section.
2.
Power
supply
circuits
LF601
and
ambient
capacitors
from
a
line
filter
whose
function
is
to
protect
the
power
supply
from
power
line
surges
and
noise,
and
to
prevent
the
power
supply
from
radiating
noise
back
out
to
series
with
the
degaussing
coil
which
is
across
the
AC
line,
initially,
when
the
receiver
is
turned
”on”
and
the
resistance
of
the
posistor
is
low.
Causing
the
current
to
flow
through
the
degaussing
coil
and
the
demagentizing
action
occure
at
CPT.
As
the
posistor
heats,
its
resistance
increases
to
the
point
that
the
current
flow
through
the
degaussing
coil
becomes
negligiblity.
The
TAD4601
has
been
controlled
DC
out
put
voltage
and
has
been
designed
for
driving,
controlling,
and
protecting
the
switching
transistor
in
blocking
converter
power
supplies.
At
the
input
of
pin
2
the
zero
crossings
of
the
frequency
provided
by
feed
back
coil
(T602)
are
registered
and
forwarded
to
the
control
logic.
Pin
3
receives
the
rectified
amplitude
fluctuations
of
the
feed
back
coil.
The
requlating
amplifier
operates
with
an
input
voltage
of
approx.
2V
and
a
current
of
approx.
1.
4mA
depending
on
the
internal
voltage
reference,
the
over
load
recognition
simulator
pin
4
the
operating
range
of
the
control
amplifier.
The
collector
current
is
simulated
by
an
external
RC
combination
present
at
pin4
and
internally
set
throughold
voltages.
The
out
put
levels
of
the
control
amplifier
as
well
as
those
of
the
overload
recongnition
and
the
collector
current
simulator
are
compared
in
the
trigger
and
forwarded
to
the
control
logic.
Via
pin
5
it
is
possible
to
externally
inhibit
the
operation
of
the
TDA4601.
3.
Video
section
The
section
amplifiers
the
output
signal
of
the
generator
to
a
level
high
enough
to
drive
the
video
output
circuit.
Input
signal
contains
R,G,B
video
signal
and
H.V
sync.
intensity.
These
TTL
level
signals
are
positive
polarity.
Video
signal
which
applied
to
IC
301.302.303.
304.305
and
drived
via
contrast
volume,
and
connected
0301.302.303.
Finally,
drived
signals
are
applied
to
CPT
cathode
though
output
amplifier
Q351.352.353.
The
intensity
signal
which
applied
to
IC301.303.
304
and
deived
signal
is
applied
0305.
b
When
the
level
digital
signal
is
0,
0305
is
cut
off
and
emitter
of
0304
is
high
level.
The
intensity
signal
from
0304
applied
to
0301.
302.303
and
mixed
R.G.B
signal.
The
socket
board
is
a
collection
point
for
the
voltage
and
signals
required
to
operate
the
CPT.
The
board
contains
bias
and
drive
controls.
The
R.G.B
signal
are
directly
coupled
from
amplifier
of
R.G.B
main
PCB.
4.
Horizontal
and
vertical
processor
circuit
The
|C501
contains
all
the
circuits
for
sync.
separation,
vertical
oscillation,
horizontal
oscillation
AFC
and
X—RAY
protection.
The
input
signal
applies
first
to
the
sync.
separation
circuit.
and
the
sync.
signals
seprated
and
taken
out
apply
to
the
horizontal
AFC
and
vertical
sync.
separation
circuits.
VR401,
R405,
C403
conneted
to
pin
10,
provide
the
time
contant
in
the
vertical
oscillation
circuit,
the
frequency
of
oscilaton
can
be
varied
by
adjusting
VR401.
The
60Hz
signal,
originating
in
the
IC401,
and
amplified,
comes
to
pin
6
and
is
then
amplified
further
by
the
vertical
output
curcuit.
The
amplified
60Hz
signal
goes
out
through
pin
2
of
lC401
to
vertical
deflection
yokecausinga
a
sawtooth
current
to
flow
in
the
yoke
coil.
The
frequency
of
horizontal
oscillation
can
be
changed
by
means
of
VR502.
The
pulses
occurring
in
the
secondary
winding
of
FBT
are
admittred
as
the
pulses
for
sawtooth
wave
generation
through
C502
of
IC501.
These
pulses
under
integration
connected
to
pin
1
of
l0501,
and
apply
as
comparison
signal
to
the
horizontal
AFC
circuit.
The
voltage
resulting
from
comparison
and
detection
is
taken
out
through
pin
(2),
smoothened
by
C508,
R508
and
forwarded
as
the
horizontal
AFC
voltage
to
the
oscillation
circuit.
The
X-Ray
protection
circuit
operates
by
shutting
down
the
horizontal
oscillator
in
reference
to
a
voltage
produced
by
rectifying
the
fly
back
pulses.
This
scheme,
based
on
the
proportionality
between
flyback
pulses
and
high
voltage,
is
put
to
work
in
the
following
manner.
Flyback
pulses
of
positive
polarity
are
rectified
0551
and
C551,
and
resulting
DC
voltage
is
applied
to
pin
5
of
IC501.
When
the
high
voltage
exceeds
the
limit,
the
DC
voltage
will
be
high,
so
to
shut
down
the
horizontal
oscillator.
The
loss
of
this
oscillation
in
loss
off
rester,
but
the
DC
power
supply
remains
unaffected.
The
0550
and
T551
is
horizontal
drive
circuit.
This
circuit
is
located
oscillator
circuit
and
horizontal
output
circuit
and
serves
to
amplify
the
output
of
the
oscillator
and
to
drive
the
output-
transistor.
1-.
fl
.—
_
0‘“.
.

QQPSANr
SECTION
III
FIGURES
Timing
chart
Adjust
&
Connector
for
PCB
Main
PCB
Ass’y
dimension
Mechanical
dimension
for
C.P.T
Schematic
and
Voltagewave
form
PCB
Component
location

I.
TIMING
CHART
18.8,us
44.7;15
HORIZONTAL
3.94pts
6.62;;5
HOR.
SYNC
63.5;15
3.89ms
‘
12.78'ms
VERTICAL
0.19ms
1.53ms
VER.
SYNC
fl—ww—m—w—u—h’
—fl——*—flmh_
-—_——
16.67ms
a;