Casio TV-1450C User manual

Seavice MANUAL
& PARTS LIST soo
POCKET TELEVISION
TV=-1450C
TV=-1450N
TV=-1450D
MAY 1991
Page
Specifications
---------------------------------2-ecn
cc
nnnn
nnn
nnnn
ncn
cn
nnn
nccn
ne
nananncnnnnncncencnns
|
Block
DiaQram
--------------en20n=--nnnn
nnn
nnn
nn
nnn
nnn
nnn
nnn
nro
rn
rn
nnn
nnnnnannn
a
mir
2
Circuit
Operations
----------------------------nnnennnnn
nnn
nnn
nner
nen
nnnn
enon
nnn
onnonmnnnnnnnnnn
sane
3
Adjustment
ee a Oo a a 5
Linear PCB ------------------n2-n-n-nn-nennnnnnn ence nc cenceneennnnncnnnnnnennnnnnencesccsenen &
AID PCB ~----------n--n-nnnnn nnn manne nnn n nner nner nennncnnnccnncncnnncenanmmnnnnnnanans 10
Troubleshooting
------------------n-nn-n
nmr
nnn
nnn
nn
nner
nnn
nnn
nnn
nen
mn
nna
nnn
cn
emnnmnnnnns
12
Wiring
Diagram
-----------------------------n
enn
nnnn
nn
nn
nnnn
nnn
nnn
nnn
nnn
nnn
nmnnnnn
nnn
nnnn
on
17
PCB
Diagrams
----------------7--------nn
nn
nnnnn
none
nn
enn
nnnnnnnncennnnnnnnnnnnnrnnannnnnannnnenes
18
Exploded
View:/
Disassembly
==--<-s--2-+---=-sse
retire
mene
seen
eerce
ese
areeeen
eee
24
Electrical
Parts
List
-----------------------------
ns
-nn
nnn
nnn
nnn
nnn
nnn
nnn
nnn
nme
25
Mechanical
Parts
List
---------------~------------------
nnn
nn
nn
nnn
nnn
nn
nnn
ne
nnn
er
een
cnn
nnn
34
Lead
Identification
------------------------------------e---o2ncenecenccenceencees
eid
ceoeee
se
35
Schematic
Diagram
+S
37

SPECIFICATIONS
Specification
TV-1450C : VHF 2~12ch UHF : 21 ~ 69ch
TV-1450N : VHF 2~12ch UHF : 21 ~ 69ch
TV-1450D : VHF — UHF : 21 ~ 68ch
2. Power voltage DC 6.0V
3. Power consumption Approx. 3.8 W
4. Current consumption Approx. 630 mA
‘| 5. Battery life (with alkaline batteries) Approx. 2.0 hours
6. Power supply
7. Connection terminals
1. Reception channels
Batteries: 4AA size batteries
Car adaptor: CA-K65
AC adaptor: AD-K65
Earphone jack: 3.56 mini
External power jack: 6.0V DC IN
External antenna jack: 3.5@ mini
Audio/Video jack: 3.58
9. No. of picture element 118,580 (220 x 539) dots
: 11. Weight
12. Standard accessories Soft case, Ear phone and Test batteries (R6 x 4)
TV-1450C,TV-1450D TV-1450N
140 mm (H) x 87mm (W) x 37 mm (D)
5-1/4" (H) x 3-1/2" (W) x 1-1/2" (D)
300g excepting batteries
10.6 oz excepting batteries
AC adaptor: AD-K65 AD-K65
13. Options Car adaptor: CA-K65 CA-K65
RF connector: CF-13 —
Antenna matching device: AS-35S —
14. Body clolor

BLOCK DIAGRAM
Antenna
@ Ic200
Video
Sound } Det.
FM
AFT Circuit
AGC Circuit
Speaker
@ TU
Volume
Control
@ 10400
Tuning
Voltage
Generator
® 1C300
Chroma .
Circuit
©
D
Driver
tt
Driver
OSC
Display
Control
A/D Converter
Auto-tuning
Control
1C800,1C801
Display
Voltage.
Generator
Power
VCC2
(4.3V)
VR800
-
Supply
—
VCC7
(45V)
bg
—
VEEN
Brightness
Control
@)
—
Color
Tuner
TU
TEPE5-01(TV-1450C,
TV-1450N),
TEPB5-02(TV-1450D)
Selects
a
desired
radio
wave,
and
changes
it
to
the
video
IF
signal.
(2) - Video IF Amp. Q200 28C4238
Amplifies the video IF signal output from the tuner TU by 10 times (20dB).
()- Video, Sound, FM, AFT Det., AGC 1C200 M51348FP
Eliminates
the
carrier
wave
in
the
video
IF
signal,
and
picks
up
the
video
signal
and
the
sound
IF
signal.
Also
the
sound
signal
is
picked
up
from
the
sound
IF
signal
by
FM
detection.
(4) - Audio Amp. IC600 TA7368F
Sound amplification.
() - Chroma Circuit 1C300 M51403FP
Generates
the
tricolor
of
red,
green
and
blue
from
the
video
signal.
(@)- OSC, A/D Converter IC700 MSM6348GS-K
Converts the color signal into digital signal.
Also generates the clock pulse for the display, and controls the display.
@) — Tuning Voltage Generator IC400 MSC1169MS-K
Generates the tuning voltage from the tuning pulse (TU) output of 6).
(8) — Display Voltage Generator |C800 BA10358F, IC801 MSM6362MS-K
Generates the display voltages VO ~ V4 from VEE1 and VCC7 outputs of the power supply.

CIRCUIT OPERATIONS
Tuning Voltage Generator
= S49
”
2
3
3
<
Es
TV-1450C, TV-1450N TV-1450D
Fig. 1
This
circuit
generates
the
DC
tuning
voltage
BT
for
selecting
a
channel
from
TU
pulse
being
output
from
iC700.
iC400
has
3
circuits
for
converting
pulses
to
voltages,
selects
one
of
VHF-L,
VHF-H
or
UHF,
and
causes
the
tuning
voltage
to
be
output
from
the
TUO
terminal
(pin
no.12).
Fig.
2
and
Table
1
show
the
conditions
for
selection.
a
Function
Table — 1
BEG

Power supply
TIOO
LCI2U-I7
Wee eee ee
OC IN6V
Fig. 3
The
power
supply
consists
of
DC-DC
converter,
and
causes
the
voltages
to
be
output
as
shown
in
Table
2.
a
Table -— 2

ADJUSTMENT
SUB PCB
1) Items to be adjusted:
Measuring Instrument
Voltmeter
2) Adjustment and Test Point Locations
(TOP VIEW)
L-CONECT
C620
OO TP1
T100 FU
PHONE JACK
| TR-CONECT gai c110_Lb
VR300
DB ¢-) 382 SUB-B
3) Equipment connection / Procedure
Vcc2 voltage setting
Voltmeter
Adjust for
Input Output Output
Connection Connection | Point
See : aad
Adjust for 4.3 + 0.02V
reading on voltmeter.

Linear PCB
1) Items to be adjusted:
Video
detection
coil
adj.
TV
signal
generator,
Pattern
generator,
Oscilloscope,
Low-pass
filter
AFT
coil
adjustment
Sweep
generator,
Oscilloscope,
Voltmeter
AGC
adjustment
TV
signal
generator,
Pattern
generator,
IF
levelmeter
2) Adjustment and Test Point Locations
(TOP VIEW)
Contrast
adjustment
TV
signal
generator,
Pattern
generator,
Oscilloscope

(BOTTOM VIEW)

3) Equipment connection / Procedure
* Open solering pad A.
Pattern
generator
Video detection coil adjustment
Signal
generator
ee sce | ea | Se | Aen
Connection °
Pattern
generator
Signal
generator
* Open soldering pad A.
Sweep
generator
Low-pass
filter
Color bar
38.9MHz(TV-
1450C,N) T200
39.5MHz(TV- Oscilloscope
1450
43+.
AFT coil adjustment
Oscilloscope
38.9+5MHz(Sweep)
39.5+5MHz(Sweep)
Marker:38.9(TV1450C,N)
Marker:39.5(TV-1450D)
70dBu
* Open soldering pad A,
Pattern
generator
Pattern
generator
:TV-1450C,N
Voltmeter
:‘TV-1450D} T2094
Oscilloscope
Contrast adjustment
and grand pad B.
Signal
generator
Color bar
38.9MHz
(TV-1450C,N)
39.5MHz
signal
generator
(TV. 14800)
OdBu
Oscilloscope
Low-pass
fitter
Adjust for DC level at minimum.
Voltmeter
Adjust for 1.8 + 0.2V reading on
voltmeter.
Confirm that the marker is at
the middie of S-curve on oscillo-
scope.
Oscilloscope
Adjust step form wave to read
0.8 + 0.05 Vp-p.

AGC adjustment
Pattern Signal
generator
generator
IF
levelmeter
Output Output
*
Connection
{Point
Pattern
generator
Color
bar
Pads
Make
adjustment
according
to
65+5dBu
|
A/B/C
|
IF
levelmeter
TP2
|
the
next
table
with
reading
the
TV
signal
IF
levelmeter.
generator
Pads to be short-circuited.
ThE a eer ee se
i No Pad shorting required.
If short-circuiting of pads B or C does not
set the IF levelmeter within 81 ~ 87 dBu

A/D PCB
1) Item to be adjusted:
2) Adjustment and Test point locations:
(TOP VIEW)
Input
Output
Output
Connection
g
Connection
(Point
VR700
|_
Voltmeter
TP7
Adjust
for
2.10
+
0.05V
reading
on
voltmeter.
—-10—

ADJUSTMENT
(when
appropriate
measuring
instruments
are
not
available.)
VCC
2
voitage
*O
Make
this
adjustment
whenever
repairing.
Sub
O
Adjust
VR100
so
that
VCC2
is
4.3
+
0.02V
Video
detection
coil
*O
Make
this
adjustment
when
sensitivity
or
receiving
is
poor.
Linear
.
O
Adjust
T200
with
watching
the
screen.
'
|
AFT
coil
*O
Make
this
adjustment
when
the
auto-tuning
does
not
stop.
Linear
O
Adjust
T201
so
that
the
auto-tuning
stops.
Contrast
*O
Make
this
adjustment
when
the
contrast
is
not
good.
Linear
O
Adjust
VR300
with
watching
the
screen.
*O
Make
this
adjustment
when
no
reception
is
possible
at
all
or
the
sensitivity
is
extremely
bad.
Linear
O
Adjust
soldering
pads
A
~
C.
Clock
pulse
*O
Make
this
adjustment
when
no
synchronization
is
gained.
A/D
O
Adjust
VR700
with
watching
the
screen.
(AGC Adjustment)
AGC
By
closing
or
opening
the
adjustment
pads
C,
D
and
E,
adjust
‘Tuner’
output
pin
2
voltage
at
1
.2V.
ea
ee
ais
ate
ae
ee
ee
ae
a
ae
ae
Oe
Pa
[II
\\
To M51348 pin No.4
R234 R235 R236
R231 R232
GND
VCC2-2
=

1.
TROUBLESHOOTING
No
receiving
(The
power
supply
works
correctly,
and
each
IC
receives
correct
voltages.)
(1) Check the tuner voltage
|
PinNo.
|
Terminals
|
Voltages
|
Measuring
conditions
Next
step
when
NG
| 2 | acc | to-ts |
BU
Measure
the
voltage
with
setting
Replace
SW100
the selector SW to UHF
5
33.0
When
the
indicator
is
at
channel
Go
to
B-1
“TV-14500,N 2~6 ch of VHF.
4.0 Measure the voltage with setting Replace SW100
the selector SW to VHF
Go to the step of
“No voltage”
(2) Measure the collector waveforms of IF Amp. Q200
Check
that
the
waveforms
as
below
appear
when
the
indicator
does
not
stop.
ATOM
— 4— 16.7 msec
if the waveforms does not appear: Replace the tuner.
l Varies between 50 to 500mV.
(3) Check the waveforms at pin no.18 of IC200.
Check
that
the
waveforms
as
below
appears
when
the
indicator
passes
the
receiving
channel.
| | 12V
— 64.0 psec
When the waveforms appear: Go to (5).
(4) Measure the waveform at pin no.19 and 20 of 1C200.
Check
that
the
waveforms
as
below
appear
when
the
indicator
pases
the
receiving
channel.
TT
aan «— 16.7 msec
if
the
waveforms
do
not
appear:
Replace
component
in
order
of
C268,
T200
and
IC
200.
| | Varies between 20 to 50 mV.
4

(5)
(6
~—
(7
—
(8
—
(9)
(10)
Check the voltage at pin no. 17 of 1200.
Check the voltage varies between about 0 to 4V when the indicator does not stop.
When the voltage varies: Go to (7).
Adjusting the transformer T201.
Mark
the
initial
position,
and
turn
to
the
right
and
the
left
slightly.
At
this
condition,
check
that
voltage
amplitude
varies
at pin
no. 17 of
IC200.
if the amplitude does not vary: Replace components in order of C267 to C273, T201 and IC200.
Measure the waveform at pin no. 29 of IC300.
Check that the waveform as below appear when the indicator passes the receiving channel.
|
|
320mV
— 64.0 psec —»
If
the
waveform
do
not
appear:
Check
a
line
cutting
from
pin
no.
18
of
IC200
to
pin
no.
29
of
IC300,
and
poor
soldering
on chip
resistors
etc.
Measure the waveforms at pin no.21 to 23 of IC300.
Check the waveforms as below appear when the indicator passes the receiving channel.
|
|
Lay
— 64.0 psec
When the waveforms appear: Go to (12).
Measure the waveforms at pin no. 18 of IC300.
Check the waveforms as below appear when the indicator passes the receiving channel.
3.4V
— 64.0 usec k—
When the waveforms appear: Go to (12).
Measure the waveforms at pin no. 22 of 1C200.
Check the waveforms as below appear when the indicator passes the receiving channel.
0.8V
k— 64.0 psec—
if the waveforms do not appear: Check a line cut from pin no. 18 to pin no. 22 of IC200, and poor
soldering on chip resistors, etc.
pny OC eae

(11)
(12)
(13)
(14)
Measure
the
waveforms
at
pin
no.
23
of
1C200.
Check
the
waveforms
as
below
appear
when
the
indicator
passes
the
receiving
channel.
3.4V
—» 64.0 usec k—
If
the
waveforms
do
not
appear:
Replace
|C200
(M51348FP).
Check
that
signals
C-Sy,
AFT
and
R-G-B
from
the
Linear
PCB
go
to
pin
no.
25,
70
and
62-64
of
IC
700
respectively.
If
IC700
does
not
receive
signals:
|
Check
a
signal
line
cutting
or
poor
soldering
on
all
terminals
of
iC¢700.
Measure
the
waveforms
at
pin
no.
18
of
|C700.
Check
the
waveforms
as
below
appear.
#——» 90 psec
If
no
waveforms
appear:
Check
poor
soldering
on
OSC
block
or
replace
components
L701,
D730,
or 1C700
etc.
Measure
the
voltage
pin
no.
36
and
37
of
IC700.
If one or both is/are GND:
1)
Check
solder
bridge
on
C754
or
C755,
or
replace
components.
2)
Replace
the
UP/DOWN
KEY
SW101
or
SW102
or
IC
700.
A-1 Measure the waveforms at pin no. 11 of IC400.
Check
that
the
waveforms
as
below
appear
when
the
indicator
does
not
stop.
mr ie
— | 34psec K—
If
the
waveforms
do
not
appear,
unsolder
pin
no.
10
of
IC400,
and
check
the
waveform
at
the
solder
pad
again.
1) When the waveforms appear: Replace IC400.
2)
If
the
waveform
do
not
appear:
Check
poor
soldering
on
1C700
or
replace
it.
A-2
Remove
R420,
and
check
the
voltage
at
pin
no.
14
of
IC400
varies
between
0
to
30V.
When the voltage varies: Replace the tuner.
If does not vary: Replace IC400.
—14—

B-1 Measure the voltage at pin no. 10 of IC400.
Check
that
the
voltage
is
GND
level
when
the
indicator
is
between
2
to
6
channel.
Check
that
the
voltage
is
4
volt
level
when
the
indicator
is
between
7
to
13
channel.
If
the
voltage
is
not
in
above
voltage
level,
unsolder
pin
no.
10
of
C400,
and
measure
the
voltage
at
the
solder
pad
again.
1) When the voltage appears: Replace 1C400.
2)
If
the
voltage
does
not
appear:
Check
soldering
condition
of
1C700,
or
replace
1C700.
B-2 Measure the voltage at pin no. 15 of IC400.
Check
that
the
voltage
is
22V
when
the
indicator
is
between
2
to
6
channel.
Check
that
the
voltage
is
GND
when
the
indicator
is
between
7
to
13
channel.
1) If the voltage appears: Replace the tuner.
2) Ifthe voltage does not appear: Replace IC400.
2.
No
voltage
(Turn
off
the
power
switch
immediately
if
a
desired
voltage
does
not
appear.)
(1) Check that each voltage appears when the power line to the FL trans unit is cut.
No voltage appears: Defective back-light.
(2) Check conductivity of D115.
No conductivity: Replace D115.
(3)
Check
conductivity
between
1
and
2,
8
and
9,
3
and
5,
and
3
and
7
without
supplying
power
voltage.
lf
any
does
not
have
conductivity:
Replace
T100.
(4) Check that the voltage at pin no. 2 of T100 is 6V.
lf
the
voltage
does
not
appear,
unsolder
pin
no.
1
and
2
of
T100,
and
measure
the
voltage
at
solder
pad
of pin 2 side.
1)
If
no
voltage
appears:
Replace
SW100
or
check
the
line
from
VCC
1-1
of
SW100
to
pin
no.2
2)
When
the
voltage appears:
eae
no.1 and 2
of
T100,
and go
to
(5).
(5)
Unsolder
pin
no.
3,
5 and 7
of
T100,
and
check
the
voltage
again.
If
no voltage
appears:
Replace
all
of
Q100 ~
Q102
and
D100.
(6)
Solder
pin
no.
3
of
T100,
and
measure
the
voltage
at
pin
no.
2.
If
no voltage appears:
Turn
off the power,
and
check
the
conductivity
of
D115.
1)
If
it
is
not
normal:
Replace
D110.
2)
If
it
is
normal:
Replace
IC400.
(7)
Solder
pin
no.7
of
T100,
and
measure
the
voltage
at
pin
no.
2.
if
the
voltage
does
not
appear: Turn off
the
power,
and check
the conductivity
of
D113.
1) Ifnot normal: Replace D113.
2) If normal: Replace IC800.
—~15—

(8) Solder pin no.5 of T100 and check the voltage at pin no. 2.
If
no
voltage
appears:
Tum
off
the
power,
and
check
the
conductivity
of
D112.
if
not
normal:
Replace
D112.
(9) Unsolder L102, and measure the voltage at pin no. 2.
When the voltage appears: Replace components in order of the tuner, 1C400 and IC200.
(10) Unsolder L103, and measure the voltage at pin no. 2 of T100.
When the voltage appears: Replace IC300
If no voltage appears: Replace IC700.
—16—

WIRING DIAGRAM
re
fea Sint ‘a
Zp
Rui
hate
.
Uy
ADPcB OS rep
Ee Zi: i
+
4

PCB
DIAGRAMS
(Top
and
Bottom
Views)
Linear PCB (Top View) TV-1450C,N
Naovinmenesnctnwa
1
acer
te
iew)
TR PCB (Top V
—18—

Linear PCB (Top View) TV-1450D
—19—-—